PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.
This PDF file contains the front matter associated with SPIE Proceedings Volume 8175, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Presently, there are already Indonesian coral reefs experiencing massive destruction caused by anthropogenic localscale
sources (sedimentation, eutrophication) and/or natural climatic global-scale sources (temperature) which can
inflict acute and/or chronic impacts on these ecosystems. This study was carried out with the aim of identifying
possible sources of impact in coral reef systems associated with two of the most populated Indonesian cities
(Makassar and Jakarta). MODIS/AQUA satellite-derived Ocean Colour (Chl a in mg m-3) and Sea Surface
Temperature (SST in °C) data were used for the 2002-2011 period. These were related with large-scale atmospheric
climatic indices, namely the Southern Oscillation Index (SOI), the Dipole Mode Index (DMI), and the North Atlantic
Oscillation Index (NAOI). Beyond the expected influence of the El Niño Index over the Indonesian region, we
present first evidence of the significant influence of the NAOI in Indonesian ecosystems. The results show strong
seasonal correlation between the NAOI and two key parameters for the coral reef health: chlorophyll a (at Jakarta)
and SST (at Makassar). During the dry season, and especially over the Spermonde coral reef system, a seasonal SST
uptrend was observed culminating in the first bleaching event registered in this area during the hottest year (2010)
since 2002.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Multispectral satellite data (WordView-2, IKONOS, QuickBird) are used to map bathymetry and spectral sea floor
classes in a range of coastal areas. The standardized physics-based data processing integrates MODIS satellite data for
the radiometric intercalibration and estimates of turbidity. This process includes corrections for sunglitter, the adjacency
and the atmospheric effect. The water depth is calculated iteratively in combination with the spectral unmixing of the
respective bottom reflectance on base of the subsurface reflectance. The final step of the processing classifies the bottom
reflectance due to the spectral signature of different bottom types and biota using a specific cluster and classification
approach. The comparison with in situ data at different sites worldwide proves the approach, but also emphasizes the
necessity of radiometric well calibrated satellite data.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Water quality monitoring in the Baltic Sea is of high ecological importance for all its neighbouring countries. They are
highly interested in a regular monitoring of water quality parameters of their regional zones. A special attention is paid to
the occurrence and dissemination of algae blooms. Among the appearing blooms the possibly toxicological or harmful
cyanobacteria cultures are a special case of investigation, due to their specific optical properties and due to the negative
influence on the ecological state of the aquatic system. Satellite remote sensing, with its high temporal and spatial
resolution opportunities, allows the frequent observations of large areas of the Baltic Sea with special focus on its two
seasonal algae blooms. For a better monitoring of the cyanobacteria dominated summer blooms, adapted algorithms are
needed which take into account the special optical properties of blue-green algae. Chlorophyll-a standard algorithms
typically fail in a correct recognition of these occurrences.
To significantly improve the opportunities of observation and propagation of the cyanobacteria blooms, the Marine
Remote Sensing group of DLR has started the development of a model based inversion algorithm that includes a four
component bio-optical water model for Case2 waters, which extends the commonly calculated parameter set chlorophyll,
Suspended Matter and CDOM with an additional parameter for the estimation of phycocyanin absorption. It was
necessary to carry out detailed optical laboratory measurements with different cyanobacteria cultures, occurring in the
Baltic Sea, for the generation of a specific bio-optical model.
The inversion of satellite remote sensing data is based on an artificial Neural Network technique. This is a model based
multivariate non-linear inversion approach. The specifically designed Neural Network is trained with a comprehensive
dataset of simulated reflectance values taking into account the laboratory obtained specific optical properties of the algae
species, according to the wavelengths of MERIS VIS/NIR bands. The input to the inversion neural network are
atmospheric corrected (Level2) MERIS bottom of atmosphere reflectances as well as viewing geometries of the sensor
from which the output maps for chlorophyll concentration, Suspended Matter concentration, CDOM absorption and
phycocyanin absorption are generated.
The paper demonstrates the theoretical basis and development of the algorithm together with a number of example
results obtained from MERIS scenes in the Baltic Sea. Furthermore it compares the phycocyanin-algorithm with the
standard DLR PCI algorithm based on the related inversion technique "Principal Component Analysis" and discusses the
different inversion approaches.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Optical remote sensing of coastal waters from space is a basic requirement for monitoring global water quality and
assessing anthropogenic impacts. However, this task remains highly challenging due to the optical complexity of the
atmosphere-water system in coastal areas. In order to support present and future multi- and hyper-spectral
calibration/validation activities for the Ocean Color Radiometry (OCR) satellites, as well as the development of new
measurements and retrieval techniques for coastal waters, City College of New York along with the Naval Research
Laboratory (Stennis) has established a scientifically comprehensive observation platform, the Long Island Sound
Coastal Observatory (LISCO). As an integral part of the NASA AERONET - Ocean Color Network, LISCO is equipped
with a multispectral SeaPRISM system. In addition, LISCO expands its observational capabilities through hyperspectral
measurements with a HyperSAS system. The related multi- and hyperspectral data processing and data quality analysis
are described. The three main OCR satellites, MERIS, MODIS and SeaWiFS, have been evaluated against the LISCO
dataset of quality-checked measurements of SeaPRISM and HyperSAS. Adjacency effects impacting satellite data have
been analyzed and found negligible. The remote sensing reflectances retrieved from satellite and in situ data are also
compared. These comparisons show satisfactory correlations (R2 > 0.91 at 547nm) and consistencies (median value of
the absolute percentage difference ~ 7.4%). It is also found that merging of the SeaPRISM and HyperSAS data at LISCO
site significantly improve the overall data quality which makes this dataset highly suitable for satellite data validation
purposes or for potential vicarious calibration activities.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
We propose a methodology to quantify errors and produce uncertainty maps for satellite-derived ocean color bio-optical
products using ensemble simulations. Ensemble techniques have been used by the environmental numerical modeling
community to propagate initialization, forcing, and algorithm error sources through-out the full simulation process, but
similar approaches have not yet been applied to satellite optical properties. Uncertainties in retrievals of bio-optical
properties from satellite ocean color imagery are related to a variety of factors, including sensor calibration, atmospheric
correction, and the bio-optical inversion algorithms. Errors propagate, amplify, and intertwine along the processing path,
so it is important to understand how the errors cascade through each step of the analysis, to assess their impact and
identify the main factors contributing to the uncertainties in the final products. Also, we are interested in producing
short-term forecasts of the bio-optical property distributions, by coupling the satellite imagery with physical circulation
models. So, in addition to the uncertainties in the satellite-derived bio-optical properties due to the above-mentioned
factors, the uncertainties in the model currents used to advect the bio-optical properties add another layer of complexity
to the problem. We outline these processes and present preliminary results for this approach.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
We examine the impact of incorrect atmospheric correction, specifically incorrect aerosol model selection, on
retrieval of bio-optical properties from satellite ocean color imagery. Uncertainties in retrievals of bio-optical properties
(such as chlorophyll, absorption and backscattering coefficients) from satellite ocean color imagery are related to a
variety of factors, including errors associated with sensor calibration, atmospheric correction, and the bio-optical
inversion algorithms. In many cases, selection of an inappropriate or erroneous aerosol model during atmospheric
correction can dominate the errors in the satellite estimation of the normalized water-leaving radiances (nLw), especially over turbid, coastal waters. These errors affect the downstream bio-optical properties. Here, we focus on only the
impact of incorrect aerosol model selection on the nLw radiance estimates, through comparisons between Moderate-
Resolution Imaging Spectroradiometer (MODIS) satellite data and in situ measurements from AERONET-OC (Aerosol
Robotic NETwork - Ocean Color) sampling platforms.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Over the past few decades, various algorithms have been developed for the retrieval of water constituents from the
measurement of ocean color radiometry, and one of those approaches is spectral optimization. This approach defines an
error function (or cost function) between the observed spectral remote sensing reflectance and an estimated spectral
remote sensing reflectance over the range of observed wavelengths, with the latter modeled using a few variables that
represent the optically active properties (such as the absorption coefficient of phytoplankton and the backscattering
coefficient of particles). The values of the variables when the error function reaches a minimum are the optimized
properties. The applications of this approach implicitly assume that there is only one global minimum condition, and that
any local minimum (if exist) can be avoided through the numerical optimization scheme. Here, with data from numerical
simulations, we show the shape of the error surface as a mechanism to visualize the solution space for the model
variables. Further, using two established models as examples, we demonstrate how the solution space changes under
different model assumptions as well as the impacts on the quality of the retrieved water properties.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Increasing efforts are devoted by the Ocean Color Radiometry community to explore the polarization features of the underwater light field in order to enhance possibilities for retrieving inherent optical properties (IOPs) of coastal waters. New instrumentations and data inversion algorithms are being developed to take into account the supplementary information contained in polarization data. However, estimating the Stokes vector components of the polarized water radiance from above water measurements is a challenging task, mainly because of their small magnitude and the strong contamination by the polarized sky light reflected from the sea surface. In this study, above-water measurements are used to assess the feasibility of such retrievals and their utility for retrieving IOPs.
The Long Island Sound Coastal Observational platform (LISCO) near Northport, NY, was established in October 2009 to support satellite data validation. In June 2010, three customized hyperspectral HyperSAS systems (HyperSAS-POL) were added to LISCO platform enabling polarization measurements. A data processing algorithm, which includes vector radiative transfer computations, was developed and used to remove the polarization signal due to sky light reflected from the sea surface (sky glint) and derive the underwater polarization field. The spectral shape of the retrieved underwater degree of polarization was then evaluated against theoretical radiative transfer computations and in situ underwater measurements. The results confirmed the validity of the polarization measurements by the LISCO site, thus validating a continuous time series starting from the beginning of June 2010 to the present which can be used for retrievals of IOPs from polarization measurements.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Remote sensing by aerial surveillance and from satellites is used operationally as a combined tool for detection and
characterization of maritime pollution by oil spills. For Germany, the Central Command for Maritime Emergencies
(CCME) applies two aircraft of the type Dornier 228 with multi-sensor systems. In addition, radar satellite images are
received via the CleanSeaNet Service.
By these means, important information is gained as a support for oil spill response and for advanced monitoring: Among
other things the existence, location and distribution of spills are delivered. This is valuable input for numerical models
for drift prediction. As part of the German "DeMarine-Environment" project a prototype for a processing chain has been
developed, validated and tested quasi operationally by the Federal Institute of Hydrology (BfG) in cooperation with the
Federal Maritime and Hydrographic Agency (BSH). In this way, a partly automatic coupling of remote sensing and
operational drift modelling has been realized.
By using this prototype, a method for drift model validation was developed: Chains of several observations by satellite or
aircraft of one individual spill are compared to the results of the drift prognosis started from the first observation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Collection of pushbroom sensor imagery from a mobile platform requires corrections using inertial measurement units
(IMU's) and DGPS in order to create useable imagery for environmental monitoring and surveillance of shorelines in
freshwater systems, coastal littoral zones and harbor areas. This paper describes a suite of imaging systems used during
collection of hyperspectral imagery in northern Florida panhandle and Gulf of Mexico airborne missions to detect
weathered oil in coastal littoral zones. Underlying concepts of pushbroom imagery, the needed corrections for directional
changes using DGPS and corrections for platform yaw, pitch, and roll using IMU data is described as well as the
development and application of optimal band and spectral regions associated with weathered oil. Pushbroom sensor and
frame camera data collected in response to the recent Gulf of Mexico oil spill disaster is presented as the scenario
documenting environmental monitoring and surveillance techniques using mobile sensing platforms. Data was acquired
during the months of February, March, April and May of 2011. The low altitude airborne systems include a temperature
stabilized hyperspectral imaging system capable of up to 1024 spectral channels and 1376 spatial across track pixels
flown from 3,000 to 4,500 feet altitudes. The hyperspectral imaging system is collocated with a full resolution high
definition video recorder for simultaneous HD video imagery, a 12.3 megapixel digital, a mapping camera using 9 inch
film types that yields scanned aerial imagery with approximately 22,200 by 22,200 pixel multispectral imagery (~255
megapixel RGB multispectral images in order to conduct for spectral-spatial sharpening of fused multispectral,
hyperspectral imagery. Two high spectral (252 channels) and radiometric sensitivity solid state spectrographs are used
for collecting upwelling radiance (sub-meter pixels) with downwelling irradiance fiber optic attachment. These sensors
are utilized for cross calibration and independent acquisition of ground or water reflectance signatures and for
calculation of the bi-directional reflectance distribution function (BRDF). Methods are demonstrated for selecting
optimal spectral regions and bands for discrimination, detection and characterization of weathered oil in the Northern
Gulf of Mexico waters and littoral zones in response to the Deepwater Horizon oil spill disaster. The techniques allow
for the use of sun and sky glint regions in imagery to identify water surface wave field characteristics as well as oil
slicks. The systems described provide unique data sets for remote sensing algorithm development and future testing of
radiative transfer models useful in studying weathered oil fate, distribution and extent.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper presents the new-generation airborne remote sensing systems SETHI and SYSIPHE, developed by ONERA,
the French Aerospace Lab, and dedicated to environmental, scientific and security applications.
Today, many scientists from climatologists to agronomists, need specific types of information that cannot be provided in
full by conventional observation systems to solve complex problems. Onera offers them a solution to use the huge
potential of multispectral and hybrid radar/optronics data.
The SETHI remote sensing system is dedicated to provide a unique combination of radar and optronics images, including
polarimetric SAR, visible and short wave infrared, multispectral images, ... This all-in-one system is operational from
2008 in radar configuration, its optronics capability becomes operational gradually.
The SYSIPHE system is the state of the art airborne hyperspectral imaging system developed in European cooperation.
With a unique wide spectral range and a fine spatial resolution, its aim is to validate and quantify the information
potential of hyperspectral imaging in military, security and environment applications.
The first section of the paper introduces the objectives of the projects and their general architecture. The second one
describes the sensors, their implementation onboard the platforms, the data processing chain and gives an overview of
the projects planning. The third section presents some significant results.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Modulation of short wind gravity-capillary waves (SGCW) due to long surface and internal waves in the presence of
surface films of different surfactant concentrations has been studied in wave tank and field experiments using Ka-band
radar. Wave tank experiments were carried out in the oval wind wave tank of the Institute of Applied Physics RAS at
different wind velocities (2 m/s to 5 m/s) and at two fetches. It was obtained that the Modulation Transfer Function
(MTF) magnitude in film slicks was several times larger than in non-slick areas, the phase of MTF was also changed in
the presence of films. Similar conclusions were made from field observations of radar backscatter modulation due to long surface and internal waves, here the effect of enhanced surface waves modulation in slick zones was revealed, too. Different physical mechanisms were taken into account to explain experiment, namely, geometrical effects, modulation of surfactant concentration, transformation of the wind velocity over the long wave profile. Theoretical analysis has demonstrated that the effect of enhanced modulation could not be explained using only the mechanisms mentioned above. MTF is assumed to be determined by the effect of bound components of short wind-wave spectrum.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Biogeographical analyses provide insights on how the Deepwater Horizon oil spill impacted large pelagic fishes. We
georeferenced historical ichthyoplankton surveys and published literature to map the spawning and larval areas of
bluefin tuna, swordfish, blue marlin and whale shark sightings in the Gulf of Mexico with daily satellite-derived images
detecting surface oil. The oil spill covered critical areas used by large pelagic fishes. Surface oil was detected in 100% of
the northernmost whale shark sightings, in 32.8 % of the bluefin tuna spawning area and 38 % of the blue marlin larval
area. No surface oil was detected in the swordfish spawning and larval area. Our study likely underestimates the extend
of the oil spill due to satellite sensors detecting only the upper euphotic zone and the use of dispersants altering crude oil
density, but provides a previously unknown spatio-temporal analysis.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The use of high-resolution imagers for determination of solar-induced fluorescence of natural bodies by observing the infilling
of Fraunhofer lines has been frequently adopted as a tool for vegetation characterization. The option to perform
those measurements from airborne platforms was addressed in the past. In-field observations gave evidence of the main
requirements for an imaging spectrometer to be used for Sun-induced fluorescence measurements such as high spectral
resolution and fine radiometric accuracy needed to resolve the shape of observed Fraunhofer lines with a high level of
accuracy. In this paper, some solutions for the design of a high spectral resolution push-broom imaging spectrometer for
Sun-induced fluorescence measurements are analysed. The main constraints for the optical design are a spectral
resolution better than 0.01 nm and a wide field of view. Due to the fine instrumental spectral resolution, bidimensional
focal plane arrays characterized by high quantum efficiency, low read-out noise, and high sensitivity are requested. The
development of a lightweight instrument is a benefit for aerospace implementations of this technology. First results
coming from laboratory measurements and optical simulations are presented and discussed taking into account their
feasibility.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The study of spatio-temporal trends for key water quality parameters in the Maltese coastal waters is hindered
by the lack of systematic observations spanning over the full domain and for sufficiently long time periods.
Satellite data offers an alternative source of information, but requires ground truthing against in situ
measurements. The aim of this study is to attempt the statistical comparison of MODIS ocean colour data, for a
near-shore marine area off the north-east coastline of Malta, with in situ surface chlorophyll-a measurements,
and to extract a twelve-month ocean colour data series for the same marine area. Peaks in surface chlorophyll-a
concentration occurred in the January-February period, with lowest values being recorded during the early
spring period. Log bias values indicate that the MODIS dataset under-estimates the surface chlorophyll-a values,
whilst RMSD and r2 values suggest that the match-up between satellite and in situ values is only partly consistent.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Time series (1997-2008) of near-shore altimetry data and in-situ tide gauge records have been analyzed to investigate the
seasonal variability of sea level along the Gulf of Cadiz. A high level of agreement was obtained between altimeter and
in-situ observations, indicating that altimeter data can be a valuable tool to study the sea level seasonal cycle near the
coast. Harmonic analysis showed that more than 95% of the average seasonal cycle is explained by the annual and, to a
lesser extent, semiannual components. The average seasonal cycle of sea level anomalies is very similar at the four
coastal stations, with minimum values during winter and maximum during autumn. Atmospheric pressure accounts for
20-38% of the sea level variability, its effect diminishing toward the Strait of Gibraltar. The steric contribution is notable
at the westernmost stations (32-37%) and it also decreases eastward (9-17%). River discharge explains about 15% of the
sea level variability, indicating that its effects should be taken into account. The contribution of direct atmospheric
forcing for a section of the sea level time series (1997-2001) has also been explored using the output of a barotropic
oceanographic model (HIPOCAS project) forced with wind and atmospheric pressure, revealing that the contribution of
wind is generally small (6-12%) at seasonal time scales. Small but significant correlations are found between the time
series of winter-autumn mean sea level and the winter-autumn North Atlantic Oscillation (NAO) indices. Analysis show
that the effect of NAO is mainly reflected on atmospheric pressure, wind and river runoff.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The full-scale investigations of the action of internal waves and inhomogeneous currents on the wind waves and the
near-water layer of the atmosphere were carried out in the White Sea in 2009 - 2011 yr. Measurements were carried out
from onboard of the scientific research vessel "Ekolog" by optical, radar and acoustic equipment. Hydrometeorological
conditions during observations varied essentially. Wind speed varied from 0 to 15 m/s, speed of current from 0 to 1 m/s.
Data about the field of current during different phases of tide are received. Internal waves and their manifestations on the
sea surface are registered. The special features of the flow of the powerful tidal current (to 1 m/s) around the secluded
underwater elevation and the spatial structure of surface anomalies in the field of these two-dimensional- heterogeneous
currents are analyzed. Data about a change in the characteristics of reflected from the sea surface radar signal in process
of development of wind waves are received. Experiments on procedure finalizing of the determination of sub-surface current speed according to the numerical data of radar measuring complex on the base of ship radar Icom MR-1000 and FURUNO 1942 MK2are carried out.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
A TerraSAR-X Stripmap image over the North Sea shows significant spatial variations of sea surface wind field over the
offshore wind farm Alpha Ventus. In the present study, we demonstrate the tempting potential of using high resolution
SAR to investigate spatial variations of sea surface wind field over the offshore wind farms. A newly developed X-band
Geophysical Model Function (GMF) XMOD2 is applied on the TS-X data to retrieve sea surface wind speed. By
comparing the TS-X retrieved sea surface wind field to results of the DWD wind field, in situ observations on the FiNO
platform, as well as the satellite measurement derived from the polarimetric microwave radiometer WindSat, it is found
that the SAR estimated wind field not only agrees well with other measurements, but also presents the fine-scale features
of sea surface wind field over the offshore wind farm.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The current operational algorithm for the correction of bidirectional effects from the satellite ocean color data is
optimized for typical oceanic waters. However, versions of bidirectional reflectance correction algorithms, specifically
tuned for typical coastal waters and other case 2 conditions, are particularly needed to improve the overall quality of
those data. In order to analyze the bidirectional reflectance distribution function (BRDF) of case 2 waters, a dataset of
typical remote sensing reflectances was generated through radiative transfer simulations for a large range of viewing and
illumination geometries. Based on this simulated dataset, a case 2 water focused remote sensing reflectance model is
proposed to correct above-water and satellite water leaving radiance data for bidirectional effects. The proposed model is
first validated with a one year time series of in situ above-water measurements acquired by collocated multi- and
hyperspectral radiometers which have different viewing geometries installed at the Long Island Sound Coastal
Observatory (LISCO). Match-ups and intercomparisons performed on these concurrent measurements show that the
proposed algorithm outperforms the algorithm currently in use at all wavelengths.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Hurricanes Emily, Stan and Wilma made landfall along the Yucatan Peninsula (YP) in 2005 impacting regional coastal
environments. The effects of these hurricanes on the coastal and oceanic waters around the YP were examined using
multiple satellite sensor data such as winds from QuikSCAT, sea surface temperature (SST) from MODIS, and biooptical
properties from the SeaWiFS ocean color sensor. QuikSCAT wind data revealed the hurricane paths along with
typical changes in wind speed and direction and improved interpretation of the SST and ocean color data. SST imagery
before and after hurricanes landfalling indicated variable extent of upper ocean cooling that varied with the hurricane
track and its intensity. An examination of SeaWiFS-derived backscattering coefficient at 443 nm, an optical indicator of
suspended particulate matter concentrations showed elevated levels of surface suspended material following the hurricane passages in both nearshore and offshore waters, likely due to resuspension and offshore transport. The use of multi-satellite data provided a greater understanding of the response and changes in sea surface properties to hurricanes in the YP.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
During the past decade, the world's oceans have been systematically observed by orbiting spectroradiometers such as
MODIS and MERIS. These sensors have generated a huge amount of data with unprecedented temporal and spatial
coverage. The data is freely available, but not always accessible for marine researchers with no image processing
experience. In order to provide historical and current oceanographic parameters for the jellyfish forecasting in the
JELLYFOR project, a tool for the generalized processing and archiving of satellite data was created (GRIMAS). Using
this generalized software, the large amount of remote sensing data can be accessed, and parameters such as chlorophyll a
concentration (CHL), sea surface temperature (SST) and total suspended matter concentration (TSM) can be extracted
and gridded for any region on earth. Time-series and climatologies can be easily extracted from this data archive. The
products generated can be based on the standard products, as supplied by space agencies, or can be new or regionally
calibrated products. All available MODIS and MERIS L2 images from an eight year period (2003-2010) were processed
in order to create a gridded dataset of CHL, SST (MODIS only) and of TSM for the three JELLYFOR regions. For two
of the regions, data for an extended region was also processed. Multi-year composites (climatologies) of satellite data
and time-series can provide a wealth of information for different projects in any region. Climatologies from the two
sensors are in good agreement, while significant differences can occur on a scene per scene basis. Total suspended matter
concentrations match favourably with in situ data derived from sensors on autonomous buoys. MODIS sea surface
temperature corresponds closely to temperature continuously measured underway on research vessels.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Field observations co-located and simultaneous with satellite radar imagery of biogenic slick bands on the sea
surface aimed to study relation between slicks and marine stream currents were carried out in the coastal zone of the
Black Sea. Measurements of the current velocities at different depths were performed using an acoustic Doppler current
profiler (ADCP) and surface floats. Samples of surfactant films inside/outside slick bands were collected from the water
surface with nets. The sampled films were reconstructed in laboratory conditions and measurements of the damping
coefficient of gravity-capillary waves and the surface tension were carried out using an original parametric wave method.
It is obtained that the banded slicks are characterized by enhanced concentration of surfactants due to their compression
by convergent current components. The slicks are revealed to be oriented along the stream currents and are located in the
zones of current shears. Small convergent transverse velocity components are observed near slick boundaries and are
responsible for slick formation in stream shear currents. Different examples of slicks formed by stream shear current are
described. Results of a case study of two streams of different directions merging and forming a banded slick in a shear
zone with convergent transverse current components are presented. Another case study is when a flow below a thermocline coming to the shore meets a bottom slope and a vertical current occurs resulting in horizontal divergence and convergence on the surface.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The importance of satellite altimetry in monitoring the complex ocean-atmosphere system led to the approval of the
Sentinel-3 ocean topography mission. This mission is scheduled to be launched in 2013. It will incorporate new
instruments and measuring modes that are expected to provide high-accuracy measurements for the determination of sea
level as well as ocean and land color, sea and land surface temperature with improved spatial and temporal coverage.
Nevertheless, satellite altimeter measurements, as in also the case for Sentinel-3, of homogenous quality and reliability
have to be maintained over longer periods of time. Hence, the Sentinel-3 altimetry observations, such as sea-surface
heights and sea-level anomaly fields, need to be continuously and independently connected in a common, reliable but
also long-term manner. This can be achieved by satellite calibration using dedicated research infrastructures. A
permanent calibration facility for satellite altimeters has been operating in Gavdos island, Greece as of 2004. This
facility has already been successfully and continuously determined the OSTM/Jason-2 altimeter bias. This work presents
the plans and actions to be performed to calibrate the altimeter of Sentinel-3, using the existing Gavdos Cal/Val facility,
as well as the newly developed microwave transponder.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Synthetic aperture radar (SAR) can measure directional wave spectrum based on the closed nonlinear SAR-ocean
mapping mechanism. The according wave spectrum retrieval algorithm has been developing for decades, but some
limitations remain, like high wave number cut off in azimuthal direction and the need for the first guess spectrum. Wave
spectrometer is a kind of new satellite-based real aperture radar (RAR) operating at low incidence, which has a narrow
beam and scans complete 360° by antenna rotation. It derives wave spectrum by the simple linear relation between the
wave spectrum and the modulation spectrum from the wave spectrometer. The linear coefficient can be estimated by the
nadir beam or external wind speed information. This paper proposes a method on the wave spectrum estimation based on
the joint measurement from synchronous SAR and wave spectrometer. Firstly, the modulation spectrum is derived from
the signal spectrum of the wave spectrometer, from which the relative wave spectrum can be constructed. Then the
relative wave spectrum is seen as the first guess spectrum for the wave spectrum retrieval of SAR image. Because the
relative wave spectrum has the same pattern with the real wave spectrum but has different absolute energy, we can
retrieve the directional wave spectrum by the iteration way based on the relative wave spectrum from the SAR image.
This paper makes use of simulation technology to validate the joint measurement. The simulation compares the input
spectrum and the retrieved one in terms of peak direction, peak wavelength and significant wave height, which has a
deviation of 6°, 4m and 0.3m, respectively. Simulation results show the joint measurement has the feasibility for the retrieval of directional ocean wave spectrum.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
In this paper the results of simultaneous and spatially coincident, multi-frequency, polarimetric, spatio-temporally
collocated measurements of waved pool water surface microwave reflective (radar backscattering coefficient) and
emissive (brightness temperature) characteristics angular dependences at 5.6GHz, 15GHz and 37GHz are presented.
Angular measurements were carried out for various water surface roughness parameters at clear air, cloudy and rain
conditions. For these measurements C-, Ku and Ka-band, polarimetric, combined scatterometric-radiometric systems
were used, set jointly on a mobile buggy moving along the measuring platform. Structures, operational features and the
main technical characteristics of the utilized systems are presented too. The paper has an aim as well to attract attention
of interested researchers and to invite them to perform their own or joint researches using available devices and facilities.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Geostationary Ocean Color Imager (GOCI), a payload of the Communication, Ocean and Meteorology Satellite
(COMS), is the world's first ocean color observation satellite in geostationary orbit. It was launched at Kourou Space
Center in French Guiana in June 2010. The detector array in GOCI is custom CMOS Image sensor about 2 Mega-pixels,
featuring rectangular pixel size to compensate for the Earth oblique projection.
This satellite is being operated on geostationary orbit about 36,500km far from the earth; hence it can be more influenced
by sun activities than the other on low Earth orbit. Especially, the detector is sensitive of heat and it may give rise to
increasing the defective pixels. In this paper, radiometric performance variations have been analyzed through the time
series analysis, using the offset parameters and detector temperature estimated in GOCI radiometric model. It is essential
to monitor the overall sensitivity of GOCI sensor, and it will helpful to the radiometric calibration.
In the result, we notified there was no great variation in time series of offset parameters after operating the GOCI in July
2010, but we monitored an anomaly by an operational event. One of them related to thermal electron showed slightly
increasing trend and the diurnal variation by the sun energy. Although sun interferences are occurred sometimes, any
significant anomaly isn't found. With these results of characterization, we find that GOCI has been carrying out stably in
the aspect of radiometric performance, and expect that it will be kept during the mission life.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
On August 8, 2010 morning, a large debris flow occurred in Zhouqu County, Gannan Tibetan
Autonomous Prefecture, Gansu Province, China, which has damaged Zhouqu County and its
surrounding area seriously. An UAV and airplane were sent there the day after to acquire images of
disaster area; UAV image of 0.2 meter resolution and aerial remote sensing image of 1 meter
resolution were acquired. NDRCC compared pre-disaster and post-disaster remote sensing images of
disaster area, preliminary analyzed and judged the damage condition and disaster trend. We
partitioned the coverage and affected area of debris flow into 2457 girds in high resolution remote
sensing images, hazard assessment expert group were sent to implement field investigation
according to each grid. The disaster scope and extent of loss were defined again combined with field
investigation data. Then we assessed the physical quantity of housing, infrastructure, land resource
in detail and assessed the direct economic losses. It is for the first time that remote sensing images
are integrated into the national catastrophe assessment flow of China as a major data source.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The dynamics of Terra Nova Bay (TNB) winter polynya events has been investigated by means of Sea-Ice
Concentration (SIC) maps derived from the observations of the passive microwave sensor AMSR-E; these maps
are produced by the Institute of Environmental Physics of the University of Bremen and made available on a
daily basis through its web site.
The formation and persistence of TNB polynya are thought to be due to the combined effect of katabatic
winds, advecting eastward the new formed ice, and of the Drygalski Ice Tongue which inhibits northward ice
drift into TNB.
To measure polynya extents, an image window covering the area of TNB, approximately from 74.5 to 75.5°S
and from 163 to 167°E, was extracted from the whole Antarctic SIC data set. This image window, 20 x 20 pixel
size, i.e. 125 x 125 km, which almost exactly circumscribes the TNB polynya, is used for the computation of
polynya area. On the basis of previous studies, it is assumed that a SIC pixel is "open water" when its value
goes below 70%; polynya area is then computed by multiplying the number of "open water" pixels by the area
of one pixel (39.0625 km2).
As katabatic wind, blowing eastward down from the Presley Glacier, is considered the main forcing factor in
the opening of the polynya, wind data from AWS Eneide station, located in the vicinity of the Italian Antarctic
Base "Mario Zucchelli Station" (74.8°S 164.18°E), were retrieved. Eneide station takes measurements of wind
speed and direction and air temperature every hour; wind speed and direction were then composed in one single
figure defined as effective wind, i.e. the wind component pushing eastward or at 270°.
The correlation between effective wind and polynya extents was analyzed by means of the running correlationcoefficient function Ri which can reveal the consistency between the forcing factor of the polynya and its opening. Ri function demonstrates that water areas may correlate either positively or negatively with offshore winds. This
main result is analyzed and discussed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
In this paper, submarine sand wave imaging by SAR in Taiwan shoal and their relationships with sea surface wind and sea surface current are discussed. A total of 69 synthetic aperture radar (SAR) images over 11 years between 1996 and 2006 are collected and 496 profiles of sand wave SAR images are used for the observations of sand wave SAR images. The sea surface wind estimated from NCEP/QSCAT blended wind data and the sea surface current calculated form highfrequency (HF) radar system are utilized for the study on the observations of sand wave SAR images with the wind
speed and current speed. The results show submarine sand waves in Taiwan Shoal are mainly distributed from 117.75°E
to 118.70°E and 22.7°N to 23.35°N with a high percent of 72.2. About 91% of sand waves are observed by SAR under
wind speed of 9 m/s while only 6% of sand waves are imaged above wind speed of 10 m/s. And under the adverse wind
direction, the observed sand wave reaches its maximum, while the crosswind has its minimum. These support that low
and middle wind speed and adverse wind direction are favorable for SAR imaging submarine sand waves, high wind
speed and crosswind are unfavorable. The observations of sand wave SAR images reach its seasonal maximum with a percentage of 49 in summer and have its minimum in autumn with 8%, while spring and winter has percentage of 20 and 23 respectively. The comparisons for monthly mean sea surface wind speed and monthly mean sea surface current speed with observed sand waves also shows strong relationships, which are lower sea surface wind speeds and higher sea surface current speed, the higher probability of sand waves observed by SAR. This may indicate that the higher observation of the sand waves by SAR is partly due to wind speed and current speed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Oceanic internal waves are present on all levels of the water column in deep oceans as well as in marginal coastal seas.
They appear as elongated bright and dark features in synthetic aperture radar (SAR) images as they are associated with
variable surface currents that modify the sea surface roughness patterns via current-wave interaction. Because of the
influence of SAR noise and other factors, it will be disturbed when we use computer auto-detection technique to detect
the oceanic internal wave. In this paper, an automatic method has been developed for detection of oceanic internal wave
on satellite SAR images based on the nature of sea surface oceanic internal wave. The procedure includes the edge
detection, point joining and the determination and presentation of sea surface oceanic internal wave. Examples of
detection of the oceanic internal wave on SAR images by the procedure are illustrated. The results of the sea surface
oceanic internal wave detection shown that the procedure works well.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Secchi disc is often used to measure the clarity of water in oceans and lakes. In this study, an empirical model is
developed for the monitoring of secchi disc depth (SD) in the Caspian Sea using satellite images. In situ measurements
of secchi disc depth have been performed in the Caspian Sea between July and October 2005. The in situ water samples
were taken during 25 one-day campaigns at different distances to the coast. Totally 37 secchi depth data of Caspian Sea
were gathered. The database was divided to 25 and 12 data for training and testing of empirical models, respectively. A
total of 25 Level 1B and 25 Level 2 MERIS images acquired over the Caspian Sea between July and October 2005 were
used in this study. The level 1b and level 2 data are containing of remote sensing reflectance (Rrs) data of TOA (Top Of
Atmosphere) and BOA (Bottom Of Atmosphere), respectively. The relation between secchi depth and Rrs, logarithm of
Rrs, ratio of Rrs data and logarithm of ratio of Rrs data in different wavelengths for TOA and BOA data were
investigated and then the highest correlation coefficient between secchi depth and mentioned Rrs parameters were
selected and some empirical models were developed using them. The results showed that the modeling using BOA data
can lead to better results than TOA. The best developed model using BOA data is as 1/SD=-0.138
+2.08*[Rrs(681nm)/Rrs(560nm)] with 28% error and with correlation coefficient equal to 0.86.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Continuous monitoring of phytopigment concentrations and sea surface temperature in the ocean by space-borne
methods makes possible to estimate ecological condition of biocenoses in critical areas. In the papers of the
authors (Shevyrnogov A.P., Vysotskaya G.S., Gitelzon J.I. 1996) existence of zones, which are quasi-stationary
with similar seasonal dynamics of chlorophyll concentration at surface layer of ocean, was shown. Results were
obtained on the base of processing of time series of satellite images SeaWiFS. It was shown that fronts and
frontal zones coincide with dividing lines between quasi-stationary areas, especially in areas of large oceanic
streams. The usage of the seasonal dynamics gives a possibility to circumvent influence of high-frequency
component in investigation of dynamics of spatial distribution of surface streams. In addition, an analyses of
unstable ocean productivity phenomena, stood out time series of satellite images, showed existence of areas
with different types of instability in the all Global ocean. They are observed as adjacent nonstationary zones of
different size, which are associated by different ways with known oceanic phenomena. It is evident that
dynamics of a spatial distribution of biological productivity and sea surface temperature can give an additional
knowledge of complicated picture of surface oceanic layer hydrology.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The GlobWave project funded by the European Space Agency (ESA) is to improve the uptake of satellite-derived
wind-wave and swell data by the scientific, operational and commercial user community. The newly released GlobWave
data contain synthetic aperture radar (SAR) and altimeter wave data with collocated in situ measurements. While the
derived altimeter wave data consist of total significant wave height (SWH) of ocean waves (both wind-waves and swells),
the derived SAR wave data only consist of swell SWH. In this paper, data from 2006 to 2009 are used in the validation
of GlobWave SAR data. The results show that (1) the difference between sar_swh and buoy_swh has a very small mean
deviation (MD) and relative deviation (RD) which means the SAR retrieved total SWH data is very closed to the
non-partitioned buoy data; (2) sar_swh_cal_2 and sar_swh_cal_1 have very large RD, which means the results are very
sensitive to the choice of spectral partition; (3) the calibration of sar_swh from total SWH to swell SWH has many
manipulations and is not recommended, on the contrary, the calibration of sar_swh to reduce STD between is strongly
recommended. As a conclusion, it is possible to add total SWH of ocean waves to the Globwave SAR dataset.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This study investigated upper ocean responses to Category 5 Typhoon Megi, the most intense typhoon in 2010, using
MODIS ocean color data, GHRSST L4 data, sea level anomaly data and sea surface wind data. Remarkable sea surface
cooling(~6-7°C) with large area was observed mainly to the right side of typhoon track on 22 October, which was mainly
attributed to the vertical mixing and upwelling induced by typhoon Megi. However, the sea ace temperature along the
typhoon track increased after the landfall of typhoon and then decreased again. Two cold water patches were observed
on 29 October, which were well coincident with two cores with maximum SLA decline. Therefore, we attributed the
second cooling along the typhoon track to cyclonic eddies which were triggered by typhoon Megi. On the other hand,
Strong upwelling was induced by typhoon Megi, which provided perfect conditions for the growth of phytoplankton and
caused a significant phytoplankton bloom in the SCS. Relative to historical levels over the same period, the maximum
chlorophyll a concentration increased about 20-30 times.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
A cruise was conducted in the East China Sea (ECS) in autumn 2010 to collect Dissolved Organic Carbon (DOC) and
Colored Dissolved Organic Matter (CDOM) samples. The distribution of DOC mainly controlled by the hydrography
since the relationship between DOC and salinity was significant in both East China Sea. The biological activity had a significant influence on the concentration of DOC with a close correlation between DOC and Chl a. The absorption coefficient of CDOM (a355) decreased with the salinity increasing in the shelf of East China Sea (R2=0.9045). CDOM and DOC were significantly correlated in ECS where DOC distribution was dominated largely by the Changjiang diluted water. Based on the relationship of CDOM and DOC, we estimated the DOC concentration of the surface in ECS from satellite-derived CDOM images. Some deviations induced by the biological effect and related marine DOC accumulations were discussed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Concentration of suspended sediment directly affects the optical properties such as transparency and water color, and
aquatic environment as well. The paper selects the Minjiang Estuary, southeast coast of China as study area, and has
established inversion mode of suspended sediment by coupling field data with water-leaving radiation from MODIS data
in Minjiang Estuary. Monthly-averaged concentrations and seasonal changes of suspended sediment from 2002 to 2009
were calculated and analyzed by the mode. The main results are as follows: (1) Normalized water-leaving radiance
ratio(nLw667/nLw488) from MODIS data has high relativity with the field observed turbidity by regression equation of Y = 0.618X2 -5.720X + 18.94, in which Y is turbidity, X is nLW667/nLW488 and R2 is 0.716. (2)Suspended sediment in
the Minjiang Estuary has obviously spatial and temporal distribution characteristics, that higher concentration of
suspended sediment is in coastal water and decreases from shore to sea, and highest concentration happens in winter.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The absorption and particulate backscattering coefficients are the basic parameters of the water inherent optical
properties (IOPs), which are also the basic parameters for the development and validation of the semi-analysis models of
the ocean color remote sensing. In this work, the absorption and backscattering coefficients in the East China Sea (ECS)
were measured in the summer and winter of 2009 using the three in-situ optical instruments, including the WET Labs acs,
and the HOBI Labs HydroScat-6. Based on the in-situ measured data, the distribution of the absorption and
backscattering coefficients in the ECS are analyzed. The results show that in the summer the water absorption coefficient
at 440nm (a(440nm),excluding the absorption of the pure sea water) in the surface layer is ranged from 0.022 to 0.067
m-1, and the particulate backscattering coefficient at 442nm(bbp(442nm), is between 0.00064 and 0.03274 m-1. As a
whole, both of the absorption and backscattering coefficients decrease with the offshore direction, and the high values
located at the mouth of Changjiang River. In the winter, a(440nm) is between 0.051 and 0.887 m-1, and bbp(442nm) is
ranged from 0.000639 to 0.14614 m-1 at the surface layer. The spatial distributions in winter are similar as the summer,
with the high value in the coast and low value in the offshore. The absorption and backscattering coefficients in winter
are significantly larger than the summer's, especially in coastal area near the mouth of Changjiang River, which maybe
caused by the southward Fujian-Zhejiang coastal current occurring in winter. As the vertical profile distributions, we find
that both of the absorption and backscattering coefficients present a layer structure, which caused by the stratification of
the sea water in the summer; while in the winter, affected by the strong wind disturbing, both of the absorption and
backscattering coefficients are thoroughly vertical mixing. To our knowledge, it is the first time giving the distribution of
the absorption and backscattering coefficients in the East China Sea.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The paper is devoted to the development of remote optical methods for monitoring of sea surface. The technique for
creating of large scale optical range - time - intensity optical images (RTI images) of sea surface under grazing angles of
observation was developed and the optical system for monitoring of coastal zone and inland water up to some tens
kilometers was created;
Various manifestations of near surface wind on the sea surface were detected and its dynamic was observed;
The method for investigation of large scale structure of near water wind from RTI images of sea surface was proposed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The synthetic aperture radar (SAR) has been proven to be a valuable tool for high resolution ocean surface wind measurements, which is especially important for coastal waters. However, oceanic surface phenomena observed by SAR and oceanic processes which can cause the change of backscatter in SAR imagery will influence the SAR wind retrieval. Upwelling is one of the main factors and it is prevalent in summer along the Zhejiang Coast. It smoothes the sea surface
which results in the lower backscatter cross section in SAR imagery. In this article, using sea surface temperature (SST) and chlorophyll2-a data derived from EOS MODIS, the low backscatter features in ENVISAT ASAR imagery are analyzed along the Zhejiang Coast in the East China Sea. And then CMOD4 algorithm is adopted to retrieve the sea surface wind speed, using wind directions from interpolated NCEP / NCAR reanalysis data. The result of wind speed is
negatively biased due to the low Normalized Radar Cross Section (NRCS) associated with the Zhejiang Coastal Upwelling. In order to resolve impact of the coastal upwelling on SAR wind retrieval, combining high resolution numerical meteorological model wind field data, a wind speed correction model is proposed using linear robust
regression. Results show that the accuracy of SAR wind retrieval is improved in upwelling region.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The coastal area of East China Sea (ECS) suffers from the harmful algal blooms (HAB) frequently every year in the
warm season. The most common causative phytoplankton algal species of HAB in the ECS in recent years are
Prorocentrum donghaiense (dinoflagellates), Karenia mikimotoi (dinoflagellates which could produce hemolytic and
ichthyotoxins) and Skeletonema costatum (diatom). The discrimination between the dinoflagellates and diatom HAB through ocean color remote sensing approach can add the knowledge of HAB events in ECS and help to the precaution. A series of in-situ measurement consisted of absorption coefficient, total scattering and particulate backscattering coefficient was conducted in the southern coast of Zhejiang Province in May 2009, and the estuary of Changjiang River in August 2009 and December 2010, which encountered two HAB events and a moderate bloom. The Inherent Optical
Properties (IOPs) of the bloom waters have significant difference between phytoplankton species in absorption and
backscattering properties. The chlorophyll a specific absorption coefficient (a*phy(λ)) for the bloom patches (chlorophyll a concentration >6mg m-3) differ greatly from the adjacent normal seawater, with the a*phy(λ) of bloom water lower than 0.03 m2 mg-1 while the a*phy(λ) of the adjacent normal seawater is much higher (even up to 0.06 m2 mg-1). Meanwhile, the backscattering coefficients at 6 wavebands (420, 442, 470, 510, 590 and 700nm) are also remarkably lower for bloom waters (<0.01 m-1) than the normal seawater (> 0.02 m-1). The backscattering coefficient ratio (Rbp(λ)) is much lower for diatom bloom waters than for dinoflagellates types (0.01079 vs. 0.01227). A discrimination model based on IOPs is
established, and several typical dinoflagellates and diatom bloom events including Prorocentrum donghaiense, Karenia mikimotoi and Skeletonema costatum in the ECS are picked out for testing with the MODIS-L2 and L3 ocean color remote sensing products from NASA website. The result proves that the satellite-derived inherent optical properties can be used to HAB detection and the discrimination of HAB species from dinoflagellates and the diatom types in the ECS.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Internal waves are often observed by satellite remote sensing in South China Sea. In this paper, all ENVISAT ASAR
images and some ERS-2 SAR images from 2005 to 2010, which cover the whole South China Sea, are used to analyze
the spatial and temporal distribution of internal waves. The internal waves' distribution maps of whole South China Sea
will be given year by year from 2005 to 2010. And it shows that internal waves not only occur in the Northern South
China Sea (between Luzon Strait and Hainan Island), also occur in Western South China Sea (along the Vietnamese
coast) and Southern South China Sea. In the Central and Eastern South China Sea, internal wave has not been observed.
And most internal waves are seen in the shallow area. The distribution of observed internal waves is similar every year in
the South China Sea. Internal waves are observed all year, most during summer, least in winter. And internal waves can be seen all days, but most from May to August, least in December and January.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Geostationary Ocean Color Imager(GOCI) is one of three payloads on board the Communication, Ocean, and
Meteorological Satellite(COMS) launched 27th, June, 2010. For understanding GOCI imaging performance, we
constructed the Integrated Ray Tracing model consisting of the Sun model as a light source, a target Earth model,
and the GOCI optical system model. We then combined them in Monte Carlo based ray tracing computation.
Light travels from the Sun and it is then reflected from the Earth section of roughly 2500km * 2500km in
size around the Korea peninsula with 40km in spatial resolution. It is then fed into the instrument before reaching to the detector plane. Trial simulation runs for the GOCI imaging performance were focused on the combined slot images and MTF. First, we used modified pointing mirror mechanism to acquire the slot images, and then mosaiced them. Their image performance from the GOCI measurement were compared to the ray tracing simulation results. Second, we investigated GOCI in-orbit MTF performance with the slanted knife edge method applied to an East coastline image of the Korea peninsula covering from 38.04N, 128.40E to 38.01N, 128.43E. The ray tracing simulation results showed 0.34 in MTF mean for near IR band image while the GOCI image obtained 9th Sep, 2010 and 15th Sep, 2010, were used to produce 0.34 at Nyquist frequency in MTF. This study results prove that the GOCI image performance is well within the target performance requirement, and that the IRT end-to-end simulation technique introduced here can be applicable for high accuracy simulation of in-orbit performances of GOCI and of other earth observing satellite instruments.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper focuses on the coefficients in the retrieval model of wet troposphere path delay. The kind of microwave
radiometers with three frequency channels, such as TOPEX/Poseidon microwave radiometer (TMR) and Jason-1
microwave radiometer (JMR), is discussed. A process of extracting these retrieval coefficients from the data of bright
temperature and relevant physical quantities is presented. The data of JMR are used to extract the retrieval coefficients
and validate this extracting process. A good agreement is shown between the data retrieved with the retrieval coefficients
and the data of JMR.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Sea ice is a good indicator to monitor the global climate change. Many of previous studies using the satellite
observations show a steady decline in Arctic sea ice. The study investigates the characteristics of the averaged
surface roughness, and refractive index from March 2003 to July 2011 using the AMSR-E daily data. The surface
roughness and refractive index of the sea ice is retrieved using a unique inversion algorithm based on the
characteristics of the polarized reflectivities, the Hong approximation, and the incidence angles of the many current
passive microwave satellite sensors. The averaged roughness and refractive index show the downward trend and
opposite signature with an acceleration, respectively. From the seasonal variations, the averaged roughness and
refractive index show the minimum and maximum values in the summer period, respectively. In addition, the annual
peaks of two physical parameters exhibit the phase difference of a month. In conclusion, this research provides a
physical explanation that the sea ice is melting increasingly using the satellite observation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The development of algorithm for the detection and monitoring of red tides, using data from Medium Resolution
Imaging Spectrometer (MERIS), is discussed. The interpretation of in-situ measured remote-sensing reflectance spectra
above both waters is presented in this paper. And a radiative transfer model based on Matrix Operator techniques is used
to study feature of the reflectance peak near 700nm. Based on the analysis of measured and modeled spectrums, the redshift
phenomenon is obviously observed above the red tide water. The reflectance peak is observed to shift progressively
from a centre wavelength of 683nm (clear and green water) to longer wavelengths (red tide waters). By using MERIS
fluorescence bands, the line height at 681 nm (LH681) and 709 nm (LH709) above a baseline through the measurements
at 665 nm and 753 nm are calculated. It is found that due to the red-shift phenomenon the LH709 is much higher than
LH681 in red tide waters. So in this paper, the ratio of LH709 to LH681 is used as an index to detect the red tides. The
results of operational red tide detection in the East China Sea have been presented.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Asian dust often occurring in the spring can be transported to the China Sea, even far to the North Pacific region. In this
process, the dust deposition brings some nutrients and microelements into ocean and can affect the marine ecosystem
significantly, such as the phytoplankton populations. In this study, we firstly analyze the monthly variations of
chlorophyll a (Chla) concentrations and aerosol optical thickness (AOT), and then consider three major dust storm events
during April 2006 to study their impact on the chlorophyll concentrations along the track of the dust storm using satellite
observations over the Yellow Sea, including AOT and the Chla from Modis, composited sea surface temperature (SST)
from TRMM / TMI and AMSR-E, and sea surface winds (SSW) from Quikscat. The central of North Yellow Sea (38-
39°N,123-124°E) and South Yellow Sea (35-37°N, 123-125°E) are regions where Chla blooming frequently during
dust events. The Chla usually up to 5-12mg/m3 and the max value even greater than 30 mg/m3. Without high wind speed
and suitable temperature, dust deposition could also cause chlorophyll concentrations increased, but its impact region is
limited and intensity is small in the Yellow Sea. Due to the AOT usually overflow or failure over dust regions, the high
AOT can denote dust event. In the future, the dust aerosol optical thickness and other properties need to be estimated for
further study on the ocean biogeochemical response to Asian dust events.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
In this article, EOS MODIS sea surface temperature (SST) data are used to observe the Zhejiang Coastal Upwelling in
the East China Sea. MODIS SST data in summer from 2007 to 2009 are selected and processed. Based on the
upwelling's temperature features in SST imagery, a temperature threshold approach is established to measure the
physical parameters of the upwelling. And then the temporal and spatial characteristics of the upwelling are analyzed.
Results show that the upwelling distributes along the Zhejiang Coast running from south to northeast, and covers an
average area of 11,000 square kilometers. The mean temperature of the upwelling is about 25~28°C, and its temperature
difference from surrounding non-upwelling waters is in the ranges of 2~4°C. The upwelling appears in June and
develops to its strongest period in July and August, and then it weakens and vanishes in late September. Three years of
observational results reveal that the upwelling has short-time, seasonal and interannual variances. The upwelling is also
closely related to the coastal topography.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Hypoxia has been widely observed in estuarine area and some reports have focused on the East China Sea over the past
decade. With the increasing nutrient load from Changjiang (Yangtze) River, a severe hypoxia zone was found in
summer. The mechanism and maintenance of hypoxia is due to the large density stratification caused by the significant
salinity difference between the fresh plume and salty water. Consumption of oxygen in bottom waters is linked to
biological oxygen demand fueled by organic matter from primary production in the nutrient-rich river plume. Hypoxia
occurs when this consumption exceeds replenishment by diffusion, turbulent mixing or lateral advection of oxygenated
water. The margins off the Changjiang are affected the most by summer hypoxia. Physical thermohaline stratification
plays an important role in the Changjiang shelf during summer. In this study, we discusses the relationship between
hypoxia and the stratification according to the surface temperature reversed from satellite, in situ observed data and time
series of profile data obtained from hypoxia buoy, which was especially designed for hypoxia identification. We
examined the occurrence of seasonal hypoxia in the bottom waters of river-dominated ocean margins off the Changjiang
River and compared the stratification procedure leading to the depletion of oxygen. A simulation for stratification was
performed to calculate the seawater temperature vertical profile. By collecting the historical investigated data, we
constructed a parametric structural model between surface and bottom temperature. Based on the parameterization of the
layered structure of seawater temperature vertical profile, the simulation method was used to calculate the parameter
distributions of stratification structure. When the real time outputs of SST and buoy-based profile were received, the
parametric model figured a set of major characteristic parameters of each profile directly: sea surface temperature, mixed layer depth, thermocline depth, and temperature gradient. Hence, the approach would achieve the goal of reconstructing the regional thermocline profile directly. The thermocline reflects the ocean temperature field's important physics characteristics, and can be used in analysis of the influence on the exchange of the oxygen.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.