This PDF file contains the front matter associated with SPIE Proceedings Volume 9241, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

This paper provides an overview of ground based operational remote sensing activities that enable a broad range of missions at the Eastern Range (ER), which includes the National Aeronautics and Space Administration (NASA) Kennedy Space Center (KSC) and U.S. Air Force Cape Canaveral Air Force Station (CCAFS). Many types of sensors are in use by KSC and across the ER. We examine remote sensors for winds, lightning and electric fields, precipitation and storm hazards. These sensors provide data that are used in real-time to evaluate launch commit criteria during space launches, major ground processing operations in preparation for space launches, issuing weather warnings/watches/advisories to protect over 25,000 people and facilities worth over $20 billion, and routine weather forecasts. The data from these sensors are archived to focus NASA launch vehicle design studies, to develop forecast techniques, and for incident investigation. The wind sensors include the 50-MHz and 915-MHz Doppler Radar Wind Profilers (DRWP) and the Doppler capability of the weather surveillance radars. The atmospheric electricity sensors include lightning aloft detectors, cloud-to-ground lightning detectors, and surface electric field mills. The precipitation and storm hazards sensors include weather surveillance radars. Next, we discuss a new type of remote sensor that may lead to better tracking of near-Earth asteroids versus current capabilities. The Ka Band Objects Observation and Monitoring (KaBOOM) is a phased array of three 12 meter (m) antennas being built as a technology demonstration for a future radar system that could be used to track deep-space objects such as asteroids. Transmissions in the Ka band allow for wider bandwidth than at lower frequencies, but the signals are also far more susceptible to de-correlation from turbulence in the troposphere, as well as attenuation due to water vapor, which is plentiful in the Central Florida atmosphere. If successful, KaBOOM will have served as the pathfinder for a larger and more capable instrument that will enable tracking 15 m asteroids up to 72 million kilometers (km) away, about half the distance to the Sun and five times further than we can track today. Finally, we explore the use of Site Test Interferometers (STI) as atmospheric sensors. The STI antennas continually observe signals emitted by geostationary satellites and produce measurements of the phase difference between the received signals. STIs are usually located near existing or candidate antenna array sites to statistically characterize atmospheric phase delay fluctuation effects for the site. An STI measures the fluctuations in the difference of atmospheric delay from an extraterrestrial source to two or more points on the Earth. There is a three-element STI located at the KaBOOM site at KSC.

Earth’s changing environment impacts every aspect of life on our planet and climate change has profound implications on society. Studying Earth as a single complex system is essential to understanding the causes and consequences of climate change and other global environmental concerns. NASA’s Earth Science Division (ESD) shapes an interdisciplinary view of Earth, exploring interactions among the atmosphere, oceans, ice sheets, land surface interior, and life itself. This enables scientists to measure global and climate changes and to inform decisions by Government, other organizations, and people in the United States and around the world. The data collected and results generated are accessible to other agencies and organizations to improve the products and services they provide, including air quality indices, disaster prediction and response, agricultural yield projections, and aviation safety. ESD’s Flight Program provides the spacebased observing systems and supporting infrastructure for mission operations and scientific data processing and distribution that support NASA’s Earth science research and modeling activities. The Flight Program currently has 17 operating Earth observing space missions, including the recently launched Global Precipitation Measurement (GPM) mission and the Orbiting Carbon Observatory-2 (OCO-2). The ESD has 18 more missions planned for launch over the next decade. These include first and second tier missions from the 2007 Earth Science Decadal Survey, Climate Continuity missions to assure availability of key climate data sets, and small competitively selected orbital and instrument missions of opportunity belonging to the Earth Venture (EV) Program. The International Space Station (ISS) is being used to host a variety of NASA Earth science instruments. An overview of plans and current status will be presented.

The Global Precipitation Measurement (GPM) mission is an international partnership co-led by NASA and the Japan Aerospace Exploration Agency (JAXA). The mission centers on the GPM Core Observatory and consists of an international network, or constellation, of additional satellites that together will provide next-generation global observations of precipitation from space. The GPM constellation will provide measurements of the intensity and variability of precipitation, three-dimensional structure of cloud and storm systems, the microphysics of ice and liquid particles within clouds, and the amount of water falling to Earth’s surface. Observations from the GPM constellation, combined with land surface data, will improve weather forecast models; climate models; integrated hydrologic models of watersheds; and forecasts of hurricanes/typhoons/cylcones, landslides, floods and droughts. The GPM Core Observatory carries an advanced radar/radiometer system and serves as a reference standard to unify precipitation measurements from all satellites that fly within the constellation. The GPM Core Observatory improves upon the capabilities of its predecessor, the NASA-JAXA Tropical Rainfall Measuring Mission (TRMM), with advanced science instruments and expanded coverage of Earth’s surface. The GPM Core Observatory carries two instruments, the NASA-supplied GPM Microwave Imager (GMI) and the JAXA-supplied Dual-frequency Precipitation Radar (DPR). The GMI measures the amount, size, intensity and type of precipitation, from heavy-tomoderate rain to light rain and snowfall. The DPR provides three-dimensional profiles and intensities of liquid and solid precipitation. The French Centre National d’Études Spatiales (CNES), the Indian Space Research Organisation (ISRO), the U.S. National Oceanic and Atmospheric Administration (NOAA), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the U.S. Department of Defense are partners with NASA and JAXA. The GPM Core Observatory was launched from JAXA’s Tanegashima Space Center on an H-IIA launch vehicle on February 28, 2014 Japan Standard Time (JST). The mission has completed its checkout and commissioning phase and is in Operations Phase. The current status and early results will be discussed.

OCO-2 (Orbiting Carbon Observatory-2) is the first NASA (National Aeronautics and Space Administration) mission dedicated to studying atmospheric carbon dioxide, specifically to identify sources (emitters) and sinks (absorbers) on a regional (1000 km x 1000 km) scale. The mission is designed to meet a science imperative by providing critical and urgent measurements needed to improve understanding of the carbon cycle and global climate change processes. The single instrument consisting of three grating spectrometers was built at the Jet Propulsion Laboratory, but is based on the design co-developed with Hamilton Sundstrand Corporation for the original OCO mission. The instrument underwent an extensive ground test program. This was generally made possible through the use of a thermal vacuum chamber with a window/port that allowed optical ground support equipment to stimulate the instrument. The instrument was later delivered to Orbital Sciences Corporation for integration and test with the LEOStar-2 spacecraft. During the overall ground test campaign, proper function and performance in simulated launch, ascent, and space environments were verified. The observatory was launched into space on 02 July 2014. Initial indications are that the instrument is meeting functional and performance specifications, and there is every expectation that the spatially-order, geo-located, calibrated spectra of reflected sunlight and the science retrievals will meet the Level 1 science requirements.

Launched 10 June 2011, the NASA’s Aquarius instrument onboard the Argentine built and managed Satélite de Aplicaciones Científicas (SAC-D) has been tirelessly observing the open oceans, confirming and adding new knowledge to the not so vast measured records of our Earth’s global oceans. This paper reviews the data collected over the last 3 years, it’s findings, challenges and future work that is at hand for the sleepless oceanographers, hydrologists and climate scientists. Although routine data is being collected, a snapshot is presented from almost 3-years of flawless operations showing new discoveries and possibilities of lot more in the future. Repetitive calibration and validation of measurements from Aquarius continue together with comparison of the data to the existing array of Argo temperature/salinity profiling floats, measurements from the recent Salinity Processes in the Upper Ocean Regional Study (SPURS) in-situ experiment and research, and to the data collected from the European Soil Moisture Ocean Salinity (SMOS) mission. This all aids in the optimization of computer model functions to improve the basic understanding of the water cycle over the oceans and its ties to climate. The Aquarius mission operations team also has been tweaking and optimizing algorithms, reprocessing data as needed, and producing salinity movies that has never been seen before. A brief overview of the accomplishments, technical findings to date will be covered in this paper.

The Stratospheric Aerosol and Gas Experiment III on the International Space Station (SAGE III/ISS) mission will provide the science community with high-vertical resolution and nearly global observations of ozone, aerosols, water vapor, nitrogen dioxide, and other trace gas species in the stratosphere and upper-troposphere. SAGE III/ISS measurements will extend the long term Stratospheric Aerosol Measurement (SAM) and SAGE data record begun in the 1970s. The multi-decadal SAGE ozone and aerosol data sets have undergone intense scrutiny and are considered the international standard for accuracy and stability. SAGE data have been used to monitor the effectiveness of the Montreal Protocol. Key objectives of the mission are to assess the state of the recovery in the distribution of ozone, to reestablish the aerosol measurements needed by both climate and ozone models, and to gain further insight into key processes contributing to ozone and aerosol variability. The space station mid-inclination orbit allows for a large range in latitude sampling and nearly continuous communications with payloads. The SAGE III instrument is the fifth in a series of instruments developed for monitoring atmospheric constituents with high vertical resolution. The SAGE III instrument is a moderate resolution spectrometer covering wavelengths from 290 nm to 1550 nm. Science data is collected in solar occultation mode, lunar occultation mode, and limb scatter measurement mode. A SpaceX Falcon 9 launch vehicle will provide access to space. Mounted in the unpressurized section of the Dragon trunk, SAGE III will be robotically removed from the Dragon and installed on the space station. SAGE III/ISS will be mounted to the ExPRESS Logistics Carrier 4 location on the starboard side of the station. To facilitate a nadir view from this location, a Nadir Viewing Platform payload was developed which mounts between the carrier and the SAGE III Instrument Payload.

Understanding the causes and magnitude of change in the cryosphere remains a priority for earth science research. Over the past decade, NASA earth observing satellites have documented a decrease in both the extent and thickness of Arctic sea ice, and ongoing loss of grounded ice from the Greenland and Antarctic ice sheets. Understanding the pace and mechanisms of these changes requires long-term observations of ice sheets, sea ice thickness and sea ice extent. In response to this need, NASA’s Goddard Space Flight Center (GSFC) is developing the ICESat-2 mission, a nextgeneration laser altimeter designed to measure changes in ice sheet elevation, sea ice thickness, and vegetation canopy height. Scheduled for launch in late 2017 with a three year mission life, ICESat-2 will use a photon-counting micropulse laser altimeter, the advanced topographic laser altimeter system (ATLAS) instrument to collect these key data.

The NASA Earth Venture Cyclone Global Navigation Satellite System (CYGNSS) is a spaceborne mission scheduled to launch in October 2016 that is focused on tropical cyclone (TC) inner core process studies. CYGNSS attempts to resolve one of the principle deficiencies with current TC intensity forecasts, which lies in inadequate observations and modeling of the inner core. CYGNSS is specifically designed to address these two limitations by combining the all-weather performance of GNSS bistatic ocean surface scatterometry with the sampling properties of a constellation of satellites. CYGNSS measurements of bistatic radar cross section of the ocean can be directly related to the near surface wind speed, in a manner roughly analogous to that of conventional ocean wind scatterometers. The technique has been demonstrated previously from space by the UK-DMC mission in 2005-6.

The proposed spaceborne NASA-ISRO SAR (NISAR) mission would use the repeat-pass interferometric Synthetic Aperture Radar (InSAR) technique to measure the changing shape of Earth’s surface at the centimeter scale in support of investigations in solid Earth and cryospheric sciences. Repeat-pass InSAR relies on multiple SAR observations acquired from nearly identical positions of the spacecraft as seen from the ground. Consequently, there are tight constraints on the repeatability of the orbit, and given the narrow field of view of the radar antenna beam, on the repeatability of the beam pointing. The quality and accuracy of the InSAR data depend on highly precise control of both orbital position and observatory pointing throughout the science observation life of the mission. This paper describes preliminary NISAR requirements and rationale for orbit repeatability and attitude control in order to meet science requirements. A preliminary error budget allocation and an implementation approach to meet these allocations are also discussed.

The Meteosat Third Generation (MTG) Programme is the next generation of European geostationary meteorological systems. The first MTG satellite, MTG-I1, which is scheduled for launch at the end of 2018, will host two imaging instruments: the Flexible Combined Imager (FCI) and the Lightning Imager. The FCI will provide continuation of the SEVIRI imager operations on the current Meteosat Second Generation satellites (MSG), but with an improved spatial, temporal and spectral resolution, not dissimilar to GOES-R (of NASA/NOAA). Unlike SEVIRI on the spinning MSG spacecraft, the FCI will be mounted on a 3-axis stabilised platform and a 2-axis tapered scan will provide a full coverage of the Earth in 10 minute repeat cycles. Alternatively, a rapid scanning mode can cover smaller areas, but with a better temporal resolution of up to 2.5 minutes. In order to assess some of the data acquisition and processing aspects which will apply to the FCI, a simplified end-to-end imaging chain prototype was set up. The simulation prototype consists of four different functional blocks: - A function for the generation of FCI-like references images - An image acquisition simulation function for the FCI Line-of-Sight calculation and swath generation - A processing function that reverses the swath generation process by rectifying the swath data - An evaluation function for assessing the quality of the processed data with respect to the reference images This paper presents an overview of the FCI instrument chain prototype, covering instrument characteristics, reference image generation, image acquisition simulation, and processing aspects. In particular, it provides in detail the description of the generation of references images, highlighting innovative features, but also limitations. This is followed by a description of the image acquisition simulation process, and the rectification and evaluation function. The latter two are described in more detail in a separate paper. Finally, results from the prototype imaging chain are shown, including generated datasets, evaluation of results and conclusions derived from the first tests. An outline of planned extensions to the prototype and its role in the MTG Ground Segment development conclude the presentation.

EarthCARE is ESA’s third Earth Explorer Core Mission, with JAXA providing one instrument. The mission facilitates unique data product synergies, to improve understanding of atmospheric cloud–aerosol interactions and Earth radiative balance, towards enhancing climate and numerical weather prediction models. This paper will describe the payload, consisting of two active instruments: an ATmospheric LIDar (ATLID) and a Cloud Profiling Radar (CPR), and two passive instruments: a Multi Spectral Imager (MSI) and a Broad Band Radiometer (BBR). ATLID is a UV lidar providing atmospheric echoes, with a vertical resolution of 100 m, up to 40 km altitude. Using very high spectral resolution filtering the relative contributions of particle (aerosols) and Rayleigh (molecular) back scattering will be resolved, allowing cloud and aerosol optical depth to be deduced. Particle scatter co- and cross-polarisation measurements will provide information about the cloud and aerosol particles’ physical characteristics. JAXA’s 94.05 GHz Cloud Profiling Radar operates with a pulse width of 3.3 μm and repetition frequency 6100 to 7500 Hz. The 2.5 m aperture radar will retrieve data on clouds and precipitation. Doppler shift measurements in the backscatter signal will furthermore allow inference of the vertical motion of particles to an accuracy of about 1 m/s. MSI’s 500 m pixel data will provide cloud and aerosol information and give context to the active instrument measurements for 3-D scene construction. Four solar channels and three thermal infrared channels cover 35 km on one side to 115 km on the other side of the other instrument’s observations. BBR measures reflected solar and emitted thermal radiation from the scene. To reduce uncertainty in the radiance to flux conversion, three independent view angles are observed for each scene. The combined data allows more accurate flux calculations, which can be further improved using MSI data.

Sentinel-5 is an atmospheric monitoring mission planned in the frame of the joint EC/ESA Copernicus initiative, previously known as Global Monitoring for Environment and Security (GMES). The objective of the mission, due for launch in 2021, is the operational monitoring of trace gas concentrations for atmospheric chemistry and climate applications. It will provide accurate measurements of key atmospheric constituents such as ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide, methane, formaldehyde, and aerosol properties. The space segment will be implemented as an imaging spectrometer to be flown on EUMETSAT's Metop Second Generation satellites. From a sunsynchronous LEO orbit Sentinel-5 measurements will provide a daily global coverage at an unprecedented spatial resolution of 7x7 km at nadir and will complement the Sentinel-4 GEO data over Europe. The pushbroom imaging grating spectrometer will acquire continuous spectra of Earthshine radiance covering the UV (270-370 nm), VIS (370- 500 nm), NIR (685-773 nm) and SWIR (1590-1675 nm; 2305-2385 nm) spectral regions, with spectral resolution ranging from 0.25 nm to 1 nm.

Accurate, reliable and stable long term measurements of Earth’s Atmospheric Chemistry from Space are currently done by complex instruments, whose mass is in excess of 100 Kg. TROPOMI is the more recent instrument being developed jointly by ESA and NSO and due for launch in 2015. TROPOMI, consisting of four spectrometers ranging from UV to SWIR, is paving the way to the development of high performance spectrometers that will compose the backbone of the European Copernicus system. The objective of TROPOMI is to measure trace gases with an accuracy one order of magnitude better of what is currently done from Space. While teams of engineers are still busy finalizing TROPOMI, ESA, NSO, and TNO have launched an initiative along a different development axis: to explore the possibility of a lighter version of TROPOMI, to address a market valuing a cost effective instrument for Atmospheric Chemistry. TROPOLITE, as it is dubbed, leverages on all the technology developments and the lessons learnt from TROPOMI, but with the clear objective of a design to cost solution. Furthermore, mass and power of the instrument shall be within the envelope of a payload of a small satellite, namely 20kg and 30W and possibly within a volume of 20 x 20 x 40 cm3. The scope of TROPOLITE is to address a larger user base that is interested in an affordable instrument to perform from a small satellite some specific tasks relevant to Air Quality and/or Climate. The paper, after a short overview of the TROPOMI design and current status, presents the design philosophy of TROPOLITE, and shows what are the technologies and processes stemming from the experience gained with TROPOMI that make possible a simplified, but still very performing, version of TROPOMI. A comparison in terms of performance and functionalities of the two instruments is discussed. Finally, the development plan from the current development status of TROPOLITE up to Qualification Model is presented.

We report the results of a preparatory study aimed at exploring candidate applications that could benefit from a passive micro-satellite accompanying the L-band SAOCOM-1B satellite of Argentina, and to carry out a limited demonstration, based on data acquired during ESA airborne campaigns, of selected applications. In a first step of the study, the potential applications were identified and prioritized based on the mission context and strategic applications, scientific need, and feasibility. The next step of the study was to carry out some demonstrations using data sets acquired during the BioSAR 2007-2009, TropiSAR 2009 and IceSAR 2007 campaigns. A P-band InSAR digital elevation model was generated from BioSAR 2007 data. Time-series of interferometric coherence maps were obtained as a tool for change detection and monitoring. PolInSAR processing was carried out on BioSAR 2007 and IceSAR data.

Since the recent losses of several atmospheric instruments with good vertical sampling capabilities (SAGE II, SAGE III, GOMOS, SCIAMACHY,. . . ), the scientific community is left with very few sounders delivering concentration pro les of key atmospheric species for understanding atmospheric processes and monitoring the radiative balance of the Earth. The situation is so critical that at the horizon 2020, less than five such instruments will be on duty (most probably only 2 or 3), whereas their number topped at more than 15 in the years 2000. In parallel, recent inter-comparison exercises among the climate chemistry models (CCM) and instrument datasets have shown large differences in vertical distribution of constituents (SPARC CCMVal and Data Initiative), stressing the need for more vertically-resolved and accurate data at all latitudes. In this frame, the Belgian Institute for Space Aeronomy (IASB-BIRA) proposed a gap-filler small mission called ALTIUS (Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere), which is currently in preliminary design phase (phase B according to ESA standards). Taking advantage of the good performances of the PROBA platform (PRoject for On-Board Autonomy) in terms of pointing precision and accuracy, on-board processing ressources, and agility, the ALTIUS concept relies on a hyperspectral imager observing limb-scattered radiance and solar/stellar occultations every orbit. The objective is twofold: the imaging feature allows to better assess the tangent height of the sounded air masses (through easier star tracker information validation by scene details recognition), while its spectral capabilities will be good enough to exploit the characteristic signatures of many molecular absorption cross-sections (O3, NO2, CH4, H2O, aerosols,...). The payload will be divided in three independent optical channels, associated to separated spectral ranges (UV: 250- 450 nm, VIS: 440-800 nm, NIR: 900-1800 nm). This approach also offers better risk mitigation in case of failure in one channel. In each channel, the spectral filter will be an acousto-optical tunable filter (AOTF). Such devices offer reasonable étendue with good spectral resolution and excellent robustness and compactness. TeO2-based AOTF's have already been used in space missions towards Mars and Venus (MEX and VEX, ESA). While such TeO2 crystals are common in VIS-NIR applications, they are not transparent below 350 nm. Recent progress towards UV AOTF's have been made with the advent of KDP-based filters. Through collaboration with the Moscow State University (MSU), several experiments were conducted on a KDP AOTF and gave confidence on this material. Here, we present the general concept of ALTIUS and its optical design with particular attention on the AOTF. Several results obtained with optical breadboards for the UV and VIS ranges will be exposed, such as the O₃ and NO₂ absorption cross-section measurements, or spectral images. These results illustrate the spectral and optical performances to be expected from an AOTF-based hyperspectral imager. Their implications for ALTIUS will be discussed

Five programs, i.e. TRMM, AMSR-E, ASTER, GOSAT, GCOM-W1, GPM and ALOS-2 are going on in Japanese Earth Observation programs. ASTER has lost its short wave infrared channels. AMSR-E stopped its operation, but it started its operation from Sep. 2012. GCOM-W1 was launched on 18, May, 2012 and is operating well as well as TRMM and GOSAT. ALOS (Advanced Land Observing Satellite) was successfully launched on 24th Jan. 2006. ALOS carries three instruments, i.e., PRISM (Panchromatic Remote Sensing Instrument for Stereo Mapping), AVNIR-2 (Advanced Visible and Near Infrared Radiometer), and PALSAR (Phased Array L band Synthetic Aperture Radar). Unfortunately, ALOS has stopped its operation on 22^nd, April, 2011 by power loss. GOSAT (Greenhouse Gas Observation Satellite) was successfully launched on 29, January, 2009. GOSAT carries 2 instruments, i.e. a green house gas sensor (TANSO-FTS) and a cloud/aerosol imager (TANSO-CAI). The main sensor is a Fourier transform spectrometer (FTS) and covers 0.76 to 15 μm region with 0.2 to 0.5 cm^-1 resolution. SMILES (Super-conducting Millimeter wave Emission Spectrometer) was launched on September 2009 to ISS and started the observation, but stopped its operation on April 2010. GPM (Global Precipitation Mission) core satellite was launched on Feb. 2014. GPM is a joint project with NASA and carries two instruments. JAXA has developed DPR (Dual frequency Precipitation Radar) which is a follow on of PR on TRMM. ALOS F/O satellites are divided into two satellites, i.e. SAR and optical satellites. The first one of ALOS F/O is called ALOS 2 and carries L-band SAR. It was launched on May 2014. JAXA is planning to launch follow on of optical sensors. It is now called Advanced Optical Satellite and the planned launch date is fiscal 2019. Other future satellites are GCOM-C1 (ADEOS-2 follow on), GOSAT-2 and EarthCare. GCOM-C1 will be launched on 2016 and GOSAT-2 will be launched on 2017. Another project is EarthCare. It is a joint project with ESA and JAXA is going to provide CPR (Cloud Profiling Radar). EarthCare will be launched on 2018.

The ASTER Instrument is one of the five sensors on the NASA’s Terra satellite on orbit since December 1999. After 14 years on orbit, ASTER VNIR and TIR are still taking Earth images of good quality. The TIR radiometer has five bands from 8 to 12 μm with spatial resolution of 90 m. Each band has ten detectors. The detectors are cooled at 80 K precisely by using a Stirling cooler within 0.1 K. TIR is radiometrically calibrated by a single onboard blackbody. In the normal operation mode the blackbody is kept at 270 K, and once in 49 days the blackbody is heated up to 340 K for the gain calibration. The degradation at band 12 is largest and 48% and that at band 10 is smallest and 18%. One of the possible causes of the degradation is the contamination accretion by outgas of silicone SE9188 RTV used for TIR followed by the ultraviolet radiation. The absorption spectra of outgas of this silicon was measured at JAXA and the absorption spectra showed similar to the TIR degradation in the early days on orbit. ASTER science team is proposing the second lunar calibration at the end of terra mission for the estimation of the TIR optical characteristics. ASTER experienced first lunar calibration in April 2003 and many of the TIR bands were saturated. Due to the responsivity degradation the TIR dynamic range has extended to higher temperature. At least TIR four bands will not saturate in the next lunar calibration.

The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. JAXA and NICT developed the DPR through procurement. The contract for DPR was awarded to NEC TOSHIBA Space Systems, Ltd. The configuration of precipitation measurement using active radar and a passive radiometer is similar to TRMM. The major difference is that DPR is used in GPM instead of the precipitation radar (PR) in TRMM. The inclination of the core satellite is 65 degrees, and the flight altitude is about 407 km. The non-sun-synchronous circular orbit is necessary for measuring the diurnal change of rainfall similarly to TRMM. The DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). Both KuPR and KaPR have almost the same design as TRMM PR. The DPR system design and performance were verified through the development test and the proto flight test. DPR had handed over to NASA and integration of the DPR to the GPM core spacecraft had completed in May 2012. GPM core spacecraft satellite system test had completed in November 2013. The result of the satellite system test concerning to the DPR satisfied system requirements. GPM core observatory was shipped to Tanegashima Space Center, JAPAN and Launch Site Operations had started on November 2013 and GPM core observatory was launched at 18:37:00 (UT) on February 27, 2014 successfully. DPR orbital check out was completed in May 2014. The orbital check out and the initial calibration and validation operation result of DPR is reported.

The Advanced Land Observing Satellite-2 (ALOS-2) carries the state-of-the-art L-band Synthetic Aperture Radar (SAR) called PALSAR-2 which succeeds to the ALOS / PALSAR. PALSAR-2 has an enhanced performance in both high resolution and wide swath compared to PALSAR. It will allow comprehensive monitoring of disasters. Wider bandwidth and shorter revisit time will give better conference for interferometry SAR (INSAR) data analysis such as crustal deformation and deforestation. ALOS-2 was launched on 24th May 2014, and has been completed the initial functional verifications of onboard components and systems. This paper describes the initial operation and checkout results including the comparison with the previous SAR satellite image and the disaster monitoring. Some key features of orbit control and determination to improve the coherency of the repeat-pass INSAR observation are evaluated.

Hyperspectral Imager Suite (HISUI) is a Japanese future spaceborne hyperspectral instrument being developed by Ministry of Economy, Trade, and Industry (METI) and will be launched in 2016 or later. HISUI’s operation strategic study is described in this paper. In HISUI project, Operation Mission Planning (OMP) team will make long- and short-term observation strategy of the sensor. OMP is important for HISUI especially for hyperspectral sensor with narrow swath of 30 km. There are two major limitations on the operation of HISUI Hyperspectral Imager.　The first one is the maximum observation time per orbit. This is due to the cooling systems of the instrument to keep the instruments temperature within the design requirements. The maximum observation time per orbit is set to 15 minutes as the current baseline. The second one is maximum data downlink amount per day. This is a limitation given by communication link of the satellite bus and heavily depends on the operation of the platform satellite. The current baseline is 150 GB per day for hyperspectral sensor and 550 GB for multispectral sensor. We have developed observation coverage simulation program and studied the relationship between the limitations of sensor operation and the planned observation scenarios. The achievements of global mapping or regional monitoring need to be simulated precisely before launch. We have prepared daily global high resolution (30 second in latitude and longitude) cloud coverage data. The results of the simulations shows that HISUI will be able to acquire cloud free image of about 70 % of the terrestrial surface in three years (at the condition of 150 GB/day downlink rate).

This paper describes the activities managed by CNES (French National Space Agency) for the development of focal planes for next generation of optical high resolution Earth observation satellites, in low sun-synchronous orbit. CNES has launched a new programme named OTOS, to increase the level of readiness (TRL) of several key technologies for high resolution Earth observation satellites. The OTOS programme includes several actions in the field of detection and focal planes: a new generation of CCD and CMOS image sensors, updated analog front-end electronics and analog-to-digital converters. The main features that must be achieved on focal planes for high resolution Earth Observation, are: readout speed, signal to noise ratio at low light level, anti-blooming efficiency, geometric stability, MTF and line of sight stability. The next steps targeted are presented in comparison to the in-flight measured performance of the PLEIADES satellites launched in 2011 and 2012. The high resolution panchromatic channel is still based upon Backside illuminated (BSI) CCDs operated in Time Delay Integration (TDI). For the multispectral channel, the main evolution consists in moving to TDI mode and the competition is open with the concurrent development of a CCD solution versus a CMOS solution. New CCDs will be based upon several process blocks under evaluation on the e2v 6 inches BSI wafer manufacturing line. The OTOS strategy for CMOS image sensors investigates on one hand custom TDI solutions within a similar approach to CCDs, and, on the other hand, investigates ways to take advantage of existing performance of off-the-shelf 2D arrays CMOS image sensors. We present the characterization results obtained from test vehicles designed for custom TDI operation on several CIS technologies and results obtained before and after radiation on snapshot 2D arrays from the CMOSIS CMV family.

SOFRADIR is one of the leading companies involved in the development and manufacturing of infrared detectors for space applications. Among them, meteorological applications, meaning imagery and spectrometry, require detectors operating from medium wavelength up to high wavelength bands (around 14 μm) while having high radiometric and imaging performances. The purpose of the paper is to focus on developments made at SOFRADIR in order to answer specific needs of the infrared sounding instruments MTG IRS. Analysis of the main driven performances and constraints is presented. Then the proposed design and solutions are described and first results of the developments in progress are presented.

Energetic particles in space damage electronic components, and in particular affect the capability of Charge-Coupled Devices (CCD) to transfer photo-generated charge packets to the output node. If not properly accounted for either during the instrument design process or in the mission data processing pipeline, radiation-induced Charge Transfer Inefficiency (CTI) causes image distortion, decreases the signal-to-noise ratio, and ultimately leads to bias in the measurement carried out. CTI is a well-identified error budget contributor for mission operating in the photon-starving regime like space telescopes dedicated to Astronomy, but is less studied in the context of Earth Observation missions. We present a study conducted during the Sentinel-4/UVN CCD pre-development to provide a first assessment of the CTI effects on the Sentinel-4 measurements.

An ASIC is developed to control and data quantization for large format NIR/SWIR detector arrays. Both cryogenic and space radiation environment issue are considered during the design. Therefore it can be integrated in the cryogenic chamber, which reduces significantly the vast amount of long wires going in and out the cryogenic chamber, i.e. benefits EMI and noise concerns, as well as the power consumption of cooling system and interfacing circuits. In this paper, we will describe the development of this prototype ASIC for image sensor driving and signal processing as well as the testing in both room and cryogenic temperature.

MODIS is the key instrument for the NASA’s EOS Terra and Aqua missions, launched in late 1999 and early 2002, respectively. MODIS has 20 reflective solar bands (RSB) and 16 thermal emissive bands (TEB). MODIS RSB are calibrated on-orbit using an on-board solar diffuser and regularly scheduled lunar observations. For each instrument, the scheduled lunar observations are made through its space view (SV) port at nearly identical lunar phase angles via spacecraft roll maneuvers. Occasionally, unscheduled lunar observations at different phase angles are also collected by both Terra and Aqua MODIS. The PLEIADES system is composed of two satellites, PLEIADES-1A launched at the end of 2011 and PLEIADES-1B a year later. The PLEIADES has 5 reflective solar bands or channels (blue, green, red, nearinfrared, and panchromatic) that are calibrated on-orbit using observations of Pseudo Invariant Calibration Sites (PICS). Since launch, more than 1000 lunar images covering the phase angle range of ±115° have been acquired by PLEIADES- 1B for its on-orbit calibration and sensitivity study of lunar calibration methods. This paper provides an overview of MODIS and PLEIADES lunar observations and an assessment of their calibration difference based on lunar observations made over a range of phase angles. Also discussed in this paper are strategies and future effort that could potentially benefit other earth observing sensors and improve the calibration accuracy and consistency of existing lunar model(s).

PLEIADES is a dual Earth observation system composed of two satellites, PLEIADES-1A and PLEIADES-1B, respectively launched at the end of 2011 and 2012. This imagery system, led by CNES, has four spectral bands, blue, green, red and near infrared, with a spatial resolution of 2.8 m and a panchromatic band with a resolution of 0.7 m in vertical viewing. Its swath is about 20 km. In the framework of the PLEIADES radiometric calibration, studies took place in order to determine the calibration precision that could be reached from the acquisitions realized on the Moon. Indeed, the precisions reached from observations of calibration sites on Earth (African deserts, Antarctica, clouds, instrumented sites) are about 2-3% for most of the spectral bands in the visible and the near infrared spectra. It is very difficult to further improve this precision down to 1% because each method has its own limitations, generally due to atmospheric disturbances. In this context, the Moon seems to be an ideal calibration site: there is no atmosphere and its surface properties – thus its optical properties - are perfectly stable. Taking advantage of the high level of agility of PLEIADES, we performed an intensive observation campaign of the Moon in addition to the nominal acquisitions – when the Moon phase angle is about 40°. This intensive observation of the Moon, named POLO for Pleiades Orbital Lunar Observations, consists of a thousand acquisitions covering the phase angle range ±115 deg. The Moon was acquired as frequently as once every orbit, which represents acquisitions every 100 minutes. This paper provides an overview of these lunar experiments and an assessment of the variation of the irradiance of the Moon with phase angle. This paper also discusses a way to improve the phase angle dependence of existing lunar models.

In partnership with the European Commission and in the frame of the Copernicus program, the European Space Agency (ESA) is developing the Sentinel-2 optical imaging mission devoted to the operational monitoring of land and coastal areas. The Sentinel-2 mission is based on a satellites constellation deployed in polar sun-synchronous orbit. Sentinel-2 will offer a unique combination of global coverage with a wide field of view (290km), a high revisit (5 days with two satellites), a high spatial resolution (10m, 20m and 60m) and multi-spectral imagery (13 spectral bands in visible and shortwave infra-red domains). The first satellite is planned to be launched in mid-2015. In this context, the Centre National d’Etudes Spatiales (CNES) supports ESA to insure the calibration/validation commissioning phase during the first six months in flight. This paper provides first an overview of the Sentinel-2 system and a description of the products delivered by the ground segment associated to the main radiometric specifications to achieve. Then the paper will focus on the description of the Sentinel-2 Technical Expertise Center which is in charge of the radiometric and geometric activities during the commissioning phases of the Sentinel-2 satellites. The paper will finally address the radiometric methods and calibration sites used in this CNES image quality center to reach the specifications of the sensors, in term of absolute calibration, pixel to pixel relative sensitivity, MTF estimation and level 2 products accuracy.

Radiometric calibration of the RapidEye Multispectral Imager (MSI) and other remote sensing imaging systems is an essential task in the quantitative assessment of sensor image quality and the production of reliable data products for a wide range of geo-spatial applications. Spatially and temporally pseudo-invariant terrestrial targets have long been used to characterize Earth observation systems and provide a consistent record of their radiometric performance. This study focuses on the use of near-simultaneous acquisitions of calibration test sites by all of the RapidEye Multispectral Imagers (MSI) as a means to track the relative radiometric stability of the five sensors in the constellation. As the cameras acquired the sites with different image acquisition and solar illumination parameters, a compensation factor is derived to account for the site bidirectional-reflectance-function (BRDF) variations that occur with different sun-target-sensor acquisition conditions. The derived top-of-atmosphere reflectance is computed as a figure of merit to measure and track the constellation response to each of the test sites. The results show that the differences between the same bands on the different spacecraft are much smaller than what BlackBridge promises in the RapidEye product specifications.

Integrating sphere (IS) based uniform sources are a primary tool for ground based calibration, characterization and testing of flight radiometric equipment. The idea of a Lambertian field of energy is a very useful tool in radiometric testing, but this concept is being checked in many ways by newly lowered uncertainty goals. At an uncertainty goal of 2% one needs to assess carefully uniformity in addition to calibration uncertainties, as even sources with a 0.5% uniformity are now substantial proportions of uncertainty budgets. The paper explores integrating sphere design options for achieving 99.5% and better uniformity of exit port radiance and spectral irradiance created by an integrating sphere. Uniformity in broad spectrum and spectral bands are explored. We discuss mapping techniques and results as a function of observed uniformity as well as laboratory testing results customized to match with customer’s instrumentation field of view. We will also discuss recommendations with basic commercial instrumentation, we have used to validate, inspect, and improve correlation of uniformity measurements with the intended application.

Vacuum blackbodies have to combine performance of traditional infrared reference sources with specific features in order to operate in vacuum chamber. As their usual applications are calibration and tests of IR sensors to be loaded on satellites, earth or space radiation simulation and test of IR sensors for scientific applications, their usual features are emission over an ultra extended temperature range, knowledge of the radiated temperature with a high accuracy, extremely high uniformity of the emissive surface and extremely high emissivity. HGH developed tools to demonstrate such performances since they surpass the accuracy of usual tools.

The NASA / JPSS Airborne Sounder Testbed - Interferometer (NAST-I) is a well-proven airborne remote sensing system, which has flown in 19 previous field campaigns aboard the high altitude NASA ER-2, Northrop Grumman / Scaled Composites Proteus, and NASA WB-57 aircraft since initially being flight qualified in 1998. While originally developed to provide experimental observations needed to finalize specifications and test proposed designs and data processing algorithms for the Cross-track Infrared Sounder (CrIS) flying aboard the Suomi National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (SNPP) and the Joint Polar Satellite System, JPSS (formerly NPOESS, prior to program restructuring), its unprecedented data quality and system characteristics have contributed to a variety of atmospheric research and measurement validation objectives. This paper will provide a program overview and update, including a summary of measurement system capabilities, with a primary focus on postmission ground testing and characterization performed subsequent to the recently conducted Suomi NPP (SNPP) airborne field campaign.

Emirates Institution for Advanced Science and Technology (EIAST) was established by the Dubai Government in 2006. After three years of working together with Satrec Initiative (South Korea), EIAST was able to launch DubaiSat-1 on the 29th of July 2009. Building on the success of DubaiSat-1 and the roll out of the knowledge transfer program, UAE engineers were involved in almost 70% of the total build and design of DubaiSat-2. Targeting the commercial market, DubaiSat-2 was launched on the 21st of November 2013 for capturing 1-meter resolution images. The 1st Cal/Val phase was the most critical phase in the satellite life-time, where most of the initial measurements took place. This phase extended over the period of 25/11/2013 till 12/12/2013. Moreover, this phase included most of the relative calibration tasks, color balancing and band matching. 2nd Cal/Val phase included most of the debugging and the pointing accuracy calibration tests. This phase extended over the period of 11/02/2014 till 09/03/2014. This phase emphasized on the calibration of the pointing accuracy. The 3rd Cal/Val phase included fine tuning for the Gyro system to further increase the stability of the satellite and thus improve the pointing accuracy. Moreover, new techniques were implemented to the Pan-Sharpening and to the MTF compensation procedures to enhance the final product. This phase extended over the period of 04/05/2014 till 21/05/2014.

Meteorological satellites have become an irreplaceable weather and ocean-observing tool in China. These satellites are used to monitor natural disasters and improve the efficiency of many sectors of Chinese national economy. FY-2 series satellites are one of the key components of Chinese meteorological observing system and application system. In this paper, the operational satellite- FY-2D’s infrared channels were focused and analyzed. The instruments’ background was introduced briefly. The main payload SVISSR specifications were compared with its ancestral VISSR. The optical structure of the SVISSR was also expressed. FY-2D prelaunch calibrations methodology was introduced and the accuracies of the absolute radiometric calibration were analyzed. Some key optics on-orbit performance of FY-2D SVISSR were analyzed include onboard blackbody, cold FPA and detector noise level. All of these works show that FY- 2D’s main payload SVISSR was in a healthy status.

An evidence-led scientific case for development of a space-based polar remote sensing platform at geostationary-like (GEO-like) altitudes is developed through methods including a data user survey. Whilst a GEO platform provides a nearstatic perspective, multiple platforms are required to provide circumferential coverage. Systems for achieving GEO-like polar observation likewise require multiple platforms however the perspective is non-stationery. A key choice is between designs that provide complete polar view from a single platform at any given instant, and designs where this is obtained by compositing partial views from multiple sensors. Users foresee an increased challenge in extracting geophysical information from composite images and consider the use of non-composited images advantageous. Users also find the placement of apogee over the pole to be preferable to the alternative scenarios. Thus, a clear majority of data users find the “Taranis” orbit concept to be better than a critical inclination orbit, due to the improved perspective offered. The geophysical products that would benefit from a GEO-like polar platform are mainly estimated from radiances in the visible/near infrared and thermal parts of the electromagnetic spectrum, which is consistent with currently proven technologies from GEO. Based on the survey results, needs analysis, and current technology proven from GEO, scientific and observation requirements are developed along with two instrument concepts with eight and four channels, based on Flexible Combined Imager heritage. It is found that an operational system could, mostly likely, be deployed from an Ariane 5 ES to a 16-hour orbit, while a proof-of-concept system could be deployed from a Soyuz launch to the same orbit.

ELECNOR DEIMOS is a private Spanish company, part of the Elecnor industrial group, which owns and operates DEIMOS-1, the first Spanish Earth Observation satellite. DEIMOS-1, launched in 2009, is among the world leading sources of high resolution data. On June 19^th, 2014 ELECNOR DEIMOS launched its second satellite, DEIMOS-2, which is a very-high resolution, agile satellite capable of providing 75-cm pan-sharpened imagery, with a 12kmwide swath. The DEIMOS-2 camera delivers multispectral imagery in 5 bands: Panchromatic, G, R, B and NIR. DEIMOS-2 is the first European satellite completely owned by private capital, which is capable of providing submetric multispectral imagery. The whole end-to-end DEIMOS-2 system is designed to provide a cost-effective, dependable and highly responsive service to cope with the increasing need of fast access to very-high resolution imagery. The same 24/7 commercial service which is now available for DEIMOS-1, including tasking, download, processing and delivery, will become available for DEIMOS-2 as well, as soon as the satellite enters into commercial operations, at the end of its in-orbit commissioning. The DEIMOS-2 satellite has been co-developed by ELECNOR DEIMOS and SATREC-I (South Korea), and it has been integrated and tested in the new ELECNOR DEIMOS Satellite Systems premises in Puertollano (Spain). The DEIMOS-2 ground segment, which includes four receiving/commanding ground stations in Spain, Sweden and Canada, has been completely developed in-house by ELECNOR DEIMOS, based on its Ground Segment for Earth Observation (gs4EO®) suite. In this paper we describe the main features of the DEIMOS-2 system, with emphasis on its initial operations and the quality of the initial imagery, and provide updated information on its mission status.

The Emirates Institution for Advanced Science and Technology (EIAST) was established by the Dubai Government in 2006 with the goal of promoting a culture of advanced scientific research and technology innovation in Dubai and the UAE, and enhancing technology innovation and scientific skills among UAE nationals. EIAST launched in November 2013 the DubaiSat-2, its second Earth Observation satellite, and the first to provide VHR multispectral imagery. The satellite has successfully completed its in-orbit commissioning and it is now fully operational. ELECNOR DEIMOS is a private Spanish company, part of the Elecnor industrial group, which owns and operates DEIMOS-1, the first Spanish Earth Observation satellite, launched in 2009. ELECNOR DEIMOS launched in June 2014 its second satellite, DEIMOS-2, a VHR, agile satellite capable of providing 4-bands multispectral imagery. The whole end-to-end DEIMOS- 2 system has been designed to provide a cost-effective and highly responsive service to cope with the increasing need of fast access to VHR imagery. The two satellites, with a mass of 300 kg each, were developed in cooperation with Satrec-I (South Korea), and are based on the SpaceEye-1 platform. The two satellites have an identical payload, and produce 75- cm resolution pan-sharpened imagery across a 12-km swath. Together, they have a combined collection capacity of more than 300,000 sqkm per day. EIAST and ELECNOR DEIMOS have set up a unique, trans-national public-private partnership to operate the two satellites as a constellation, jointly commercialize the imagery of both satellites, and interchange technical and operational information to increase the efficiency of both systems. The operations of the constellation are based on four ground stations: Al Khawaneej (Dubai), Puertollano (Spain), Kiruna (Sweden) and Inuvik (Canada), which assure at least a contact per orbit with each satellite. The constellation functionalities of the ground segment were developed by EIAST and ELECNOR DEIMOS in cooperation, in order to provide a product which is exactly the same, independently of which satellite acquired the image. This paper describes the main features of the DubaiSat-2 and DEIMOS-2 systems, their combined use in constellation, and the products and services jointly offered to public and private customers worldwide. Moreover, it describes the cooperation agreement between EIAST and ELECNOR DEIMOS, and provides an update of the operational status of both missions at the time of writing.

This paper presents details of the SkySat-1 mission, which is the first microsatellite-class commercial earth- observation system to generate sub-meter resolution panchromatic imagery, in addition to sub-meter resolution 4-band pan-sharpened imagery. SkySat-1 was built and launched for an order of magnitude lower cost than similarly performing missions. The low-cost design enables the deployment of a large imaging constellation that can provide imagery with both high temporal resolution and high spatial resolution. One key enabler of the SkySat-1 mission was simplifying the spacecraft design and instead relying on ground- based image processing to achieve high-performance at the system level. The imaging instrument consists of a custom-designed high-quality optical telescope and commercially-available high frame rate CMOS image sen- sors. While each individually captured raw image frame shows moderate quality, ground-based image processing algorithms improve the raw data by combining data from multiple frames to boost image signal-to-noise ratio (SNR) and decrease the ground sample distance (GSD) in a process Skybox calls digital TDI". Careful qual-ity assessment and tuning of the spacecraft, payload, and algorithms was necessary to generate high-quality panchromatic, multispectral, and pan-sharpened imagery. Furthermore, the framing sensor configuration en- abled the first commercial High-Definition full-frame rate panchromatic video to be captured from space, with approximately 1 meter ground sample distance. Details of the SkySat-1 imaging instrument and ground-based image processing system are presented, as well as an overview of the work involved with calibrating and validating the system. Examples of raw and processed imagery are shown, and the raw imagery is compared to pre-launch simulated imagery used to tune the image processing algorithms.

In this paper, we present a feasibility study for the potential of a high spatial resolution and wide swath thermal infrared (TIR) imaging radiometer for a small satellite using a large format uncooled infrared focal plane array (IR-FPA). The preliminary TIR imaging radiometer designs were performed. One is a panchromatic (mono-band) imaging radiometer (8-12μm) with a large format 2000 x 1000 pixels uncooled IR-FPA with a pixel pitch of 15 μm. The other is a multiband imaging radiometer (8.8μm, 10.8μm, 11.4μm). This radiometer is employed separate optics and detectors for each wave band. It is based on the use of a 640 x 480 pixels uncooled IR-FPA with a pixel pitch of 25 μm. The thermal time constant of an uncooled IR-FPA is approximately 10-16ms, and introduces a constraint to the satellite operation to achieve better signal-to-noise ratio, MTF and linearity performances. The study addressed both on-ground time-delayintegration binning and staring imaging solutions, although a staring imaging was preferred after trade-off. The staring imaging requires that the line of sight of the TIR imaging radiometer gazes at a target area during the acquisition time of the image, which can be obtained by rotating the satellite or a steering mirror around the pitch axis. The single band radiometer has been designed to yield a 30m ground sample distance over a 30km swath width from a satellite altitude of 500km. The radiometric performance, enhanced with staring imaging, is expected to yield a NETD less than 0.5K for a 300K ground scene. The multi-band radiometer has three spectral bands with spatial resolution of 50m and swath width of 24km. The radiometric performance is expected to yield a NETD less than 0.85K. We also showed some preliminary simulation results on volcano, desert/urban scenes, and wildfire.

We present results of our integrated approach to the development of novel diffraction gratings. At SRON we manufacture prism-shaped silicon immersed gratings. Diffraction takes place inside the high-refractive index medium, boosting the resolving power and the angular dispersion. This enables highly compact spectrometer designs. We are continuously improving the cycle of design, simulation and test to create custom gratings for space and ground-based spectroscopic applications in the short-wave infrared wavelength range. Applications are space-based monitoring of greenhouse and pollution gases in the Earth atmosphere and ground-based SWIR spectroscopy for, a.o., characterization of exo-planet atmospheres [1]. We make gratings by etching V-shaped grooves in mono-crystalline silicon. The groove facets are aligned with the crystal lattice yielding a smooth and highly deterministic groove shape. This enables us to predict the polarized efficiency performance accurately by simulation. Feeding back manufacturing tolerances from our production process, we can also determine reliable error bars for the predicted performance. Combining the simulated values for polarized efficiency with ray-tracing, we can optimize the shape of the grating prism to eliminate unwanted internal reflections. In this contribution we present the architecture of our design and simulation platform as well as a description of test setups and typical results.

While there is no single material solution ideal for all missions, recent advances by SCHOTT in fabricating lightweight mirror blanks makes ZERODUR® a highly viable solution for many spaceborne telescopes. ZERODUR® is a well-characterized very low-expansion material. Monolithic mirrors are made without bonding or fusing out of highly homogeneous and isotropic blanks currently available in sizes up to 4m plus. We will summarize results recently given in a series of papers on the characteristics of these lightweight mirror blanks in sizes from 0.3m up, and describe the method of blank fabrication, with its compatibility to contemporary optical fabrication techniques that control of all optical spatial frequencies. ZERODUR® has a 35 year heritage in space on numerous missions, including the secondary mirror of Hubble, and all the Chandra mirrors. With the lightweighting we will discuss, ZERODUR® is now a high performing, affordable and rapidly produced mirror substrate suitable for lightweight imaging telescopes.

A diffraction grating is one of the key-components of spectral imaging spectrometers. Spectral imaging systems lead to enhanced remote sensing properties when the sensing system provides sufficient spectral resolution to identify materials from its spectral reflectance signature. The performance of diffraction gratings provide an initial way to improve instrumental resolution. Thus, subsequent manufacturing techniques of high quality gratings are essential to significantly boost spectral performance. ZEISS has developed advanced fabrication techniques to manufacture monolithic, high groove density gratings with low stray light, high diffraction efficiency and low polarization sensitivity characteristic. Gratings at ZEISS can be generated holographically in combination with ion beam plasma etching to enhance the grating profile or made by using gray-scale laser lithography technology. Holographic recording in combination with plasma etching enable the fabrication of various grating profiles to optimize efficiency including polarization behavior. Typical profile shapes are blazed type gratings, sinusoidal profiles and binary profiles allowing to optimize efficiency and polarization requirements exactly towards the required spectral range. Holographic gratings can be fabricated on plane and curved (convex, concave or free-form shape) substrates. As grating manufacturing techniques continue to cope with the challenges of enhanced remote sensing capabilities, ZEISS also can pattern large-area diffraction gratings with high resolution in the visible and shortwave infrared by using gray-scale lithography.

Optical remote sensing of the earth from air and space typically utilizes several channels from visible (VIS), near infrared (NIR) up to the short wave infrared (SWIR) spectral region. Thin-film optical filters are applied to select these channels. Filter wheels and arrays of discrete stripe filters are standard configurations. To achieve compact and light weight camera designs multi-channel filter plates or assemblies can be mounted close to the electronic detectors. Optics Balzers has implemented a micro-structuring process based on a sequence of multiple coatings and photolithography on the same substrate. High-performance band pass filters are applied by plasma assisted evaporation (plasma IAD) with advance plasma source (APS) technology and optical broad-band monitoring (BBM). This technology has already proven for various multi spectral imager (MSI) configurations on fused silica, sapphire and other substrates for remote sensing application. The optical filter design and performance is limited by the maximum coating thickness micro-structurable by photolithographic lift-off processes and by thermal and radiation load on the photoresist mask during the process Recent progress in image resolution and sensor selectivity requires improvements of optical filter performance. Blocking in the UV and NIR and in between the spectral cannels, in-band transmission and filter edge steepness are subject of current development. Technological limits of the IAD coating accuracy can be overcome by more precise coating technologies like plasma assisted reactive magnetron sputtering (PARMS) and combination with optical broadband monitoring (BBM). We present an overview about concepts and technologies for band-pass filter arrays for multi-spectral imaging at Optics Balzers. Recent performance improvements of filter arrays made by micro-structuring will be presented.

VTT Technical Research Centre of Finland has developed a spectral imager for short-wave infrared (SWIR) wavelength range. The spectral imager is based on a tunable Fabry-Perot interferometer (FPI) accompanied by a commercial InGaAs Camera. The FPI consists of two dielectric coated mirrors separated by a tunable air gap. Tuning of the air gap tunes also transmitted wavelength and therefore FPI acts as a tunable band bass filter. The FPI is piezo-actuated and it uses three piezo-actuators in a closed capacitive feedback loop for air gap tuning. The FPI has multiple order transmission bands, which limit free spectral range. Therefore spectral imager contains two FPI in a stack, to make possible to cover spectral range of 1000 – 1700 nm. However, in the first tests imager was used with one FPI and spectral range was limited to 1100-1600 nm. The spectral resolution of the imager is approximately 15 nm (FWHM). Field of view (FOV) across the flight direction is 30 deg. Imaging resolution of the spectral imager is 256 x 320 pixels. The focal length of the optics is 12 mm and F-number is 3.2. This imager was tested in summer 2014 in an unmanned aerial vehicle (UAV) and therefore a size and a mass of the imager were critical. Total mass of the imager is approximately 1200 grams. In test campaign the spectral imager will be used for forest and agricultural imaging. In future, because results of the UAV test flights are promising, this technology can be applied to satellite applications also.

Temperature and Emissivity Separation (TES) applied to multispectral or hyperspectral Thermal Infrared (TIR) images of the Earth is a relevant issue for many remote sensing applications. The TIR spectral radiance can be modeled by means of the well-known Planck’s law, as a function of the target temperature and emissivity. The estimation of these target's parameters (i.e. the Temperature Emissivity Separation, aka TES) is hindered by the circumstance that the number of measurements is less than the unknown number. Existing TES algorithms implement a temperature estimator in which the uncertainty is removed by adopting some a priori assumption that conditions the retrieved temperature and emissivity. Due to its mathematical structure, the Maximum Entropy formalism (MaxEnt) seems to be well suited for carrying out this complex TES operation. The main advantage of the MaxEnt statistical inference is the absence of any external hypothesis, which is instead characterizes most of the existing the TES algorithms. In this paper we describe the performance of the MaxEnTES (Maximum Entropy Temperature Emissivity Separation) algorithm as applied to ten TIR spectral channels of a MIVIS dataset collected over Italy. We compare the temperature and emissivity spectra estimated by this algorithm with independent estimations achieved with two previous TES methods (the Grey Body Emissivity (GBE), and the Model Emittance Calculation (MEC)). We show that MaxEnTES is a reliable algorithm in terms of its higher output Signal-to-Noise Ratio and the negligibility of systematic errors that bias the estimated temperature in other TES procedures.

This paper presents an analysis of the main artifacts introduced by the non- uniformity of the instrumental characteristics in an image dataset simulated by taking into account the main technical features of the FLORIS sensor. The dataset was produced by using a hyperspectral image simulation tool – named FLISM (Fluorescence Image Simulator for space Missions) – specifically implemented to produce images of fluorescent and non-fluorescent targets acquired by a pushbroom hyperspectral instrument. In this specific case, the available technical specifications of the FLORIS sensor were taken into account to investigate some critical issues concerning Solar Induced Fluorescence (SIF) retrieval in vegetated areas by means of the FLD (Fraunhofer Line Discriminator) method, which relies on the telluric O₂-A and O₂-B lines to decouple the weak SIF signal of vegetation from the backscattered radiance.

Consistently collecting the earth’s climate signatures remains a priority for world governments and international scientific organizations. Architecting a solution requires transforming scientific missions into an optimized robust ‘operational’ constellation that addresses the needs of decision makers, scientific investigators and global users for trusted data. The application of new tools offers pathways for global architecture collaboration. Recent (2014) rulebased decision engine modeling runs that targeted optimizing the intended NPOESS architecture, becomes a surrogate for global operational climate monitoring architecture(s). This rule-based systems tools provide valuable insight for Global climate architectures, through the comparison and evaluation of alternatives considered and the exhaustive range of trade space explored. A representative optimization of Global ECV’s (essential climate variables) climate monitoring architecture(s) is explored and described in some detail with thoughts on appropriate rule-based valuations. The optimization tools(s) suggest and support global collaboration pathways and hopefully elicit responses from the audience and climate science shareholders.

Requirements from the different disciplines of the Earth sciences on satellite missions have become considerably more stringent in the past decade, while budgets in space organizations have not increased to support the implementation of new systems meeting these requirements. At the same time, new technologies such as optical communications, electrical propulsion, nanosatellite technology, and new commercial agents and models such as hosted payloads are now available. The technical and programmatic environment is thus ideal to conduct architectural studies that look with renewed breadth and adequate depth to the myriad of new possible architectures for Earth Observing Systems. Such studies are challenging tasks, since they require formidable amounts of data and expert knowledge in order to be conducted. Indeed, trade-offs between hundreds or thousands of requirements from different disciplines need to be considered, and millions of combinations of instrument technologies and orbits are possible. This paper presents a framework and tool to support the exploration of such large architectural tradespaces. The framework can be seen as a model-based, executable science traceability matrix that can be used to compare the relative value of millions of different possible architectures. It is demonstrated with an operational climate-centric case study. Ultimately, this framework can be used to assess opportunities for international collaboration and look at architectures for a global Earth observing system, including space, air, and ground assets.

A simulation testbed has been developed to demonstrate and assess space-based wind measuring systems to reduce mission costs, extend mission life, and enable better data collection through impact studies, system trades, and the participation in Observing System Simulation Experiments (OSSEs). The numerical testbed is intended to determine the potential impact of proposed space-based and sub-orbital wind observing systems on analyses and forecasts. This paper presents the testbed used for evaluating two recent proposed space-based wind measuring concepts.

The paper provides an overview of the terrain survey realized on the base of the Russian small space vehicle (SV) “Canopus-V”. The on-ground information technology for the SV’s data processing is considered. The suggested technology includes the primary processing of the telemetric stream data, cataloguing of survey routs and forming output information products on different standard levels. The paper does briefly describe the algorithms of cloud object detection and navigation measurement processing. Besides, the paper describes the types of output information products distributed to consumers.

COSMO-SkyMed Second Generation (CSG) system has been conceived, according to Italian Space Agency (ASI) and Italian Ministry of Defence (It-MoD) requirements, at the twofold objective of ensuring operational continuity to the current constellation (COSMO-SkyMed - CSK), while improving functionality and performances. It is an “end-to-end” Italian Earth Observation Dual-Use (Civilian and Defence) Space System with Synthetic Aperture Radar (SAR) operating in X-Band. CSG mission planning purpose is to fully employ the system resources, shared between partners with very different needs, producing a mission plan that satisfies the higher priority requests and optimizes the overall plan with the remaining requests according to the users programming rights consumption. CSG Mission Planning tool provides new performances in terms of adaptability and flexibility of the planning and scheduling algorithms conceived to select and synchronize data acquisition and downloading activities. CSG planning and scheduling problem is characterized by a large size of research space and a particular structure of technical and managerial constraints that has led to the implementation of innovative design of the planning algorithms based on both priority criteria and saturation of system resources. This approach envisages two scheduling strategies: the rank-based and the optimization-based. The former strategy is firstly applied to the most important request categories, with an associated rank value or priority level; the latter is subsequently applied to the unranked or lower priority requests. This is an iterative dynamic process of finding optimal solutions able to better answer the demanding requirements coming from the needs of heterogeneous users.

OPTIMA (“Advanced methods for the analysis, integration and optimization of PRISMA mission level 1 and 2 products”) is one of the five independent scientific research projects funded by the Italian Space Agency to study the applications and performances of the imaging spectrometer and the panchromatic camera of the PRISMA mission. One of the main tasks of the project is the implementation of advanced autonomous techniques for radiometric calibration and atmospheric corrections. Besides, in the framework of the project, a sensor data simulator has been developed to test data processing algorithms. In this paper we discuss the optimized destriping procedure and the autonomous algorithm developed for the correction of the atmospheric effects. The developed procedures provides refined at sensor radiance and at-ground spectral reflectance images. Results from simulated images are presented and discussed.

A near infrared tunable liquid crystal birefringent filter is developed by cascading a series of optical elements including the wide range wire-grid polarizers, the nematic liquid crystal retarders and the quartz retarders. The center wavelength of the filter's bandpass could be randomly selected or scanned in the designed spectral range with almost exactly the same out-of-band suppression by harmoniously adjusting the driving signals. The tuning range of the filter is 900nm~1700m, the clear aperture is over 50mm, and the bandwidth FWHM is about 15nm @900nm.The filter provides more flexible functions such as random wavelength selection and arbitrary spectral scanning step. Due to the excellent imaging quality and the relatively wide angle-of-acceptance with a large aperture, the filter enable snapshot spectral imaging sensors and compact systems without any moving parts, which is of great use in a wide variety of applications such as remote sensing for environmental monitoring, agriculture census, and mineral resources detection.

The videospectral system (VSS) intended for ecological space experiment on board of the International Space Station (ISS) has been developed by the Aerospace Researches Department of the Institute of Applied Physical Problems of the Belarusian State University. The system comprises three matrix spectrometers MP-15. The polychromator of each spectrometer includes the imaging fiber, the entrance slit, concave holographic diffraction grating, and a CCD array detector. The array photodetector measures the spectral radiation distribution in rows, and the spatial distribution (image) in columns. Astigmatism is a typical aberration of polychromators based on concave spherical gratings – rays in tangential and sagittal planes are focused at different points. This degrades as for spectral and spatial resolution along the entrance slit. The proposed method of obtaining high spatial resolution without spectral resolution loss consists in the displacement of the output end of the imaging fiber along the optical axis at a specified distance from the entrance slit. After that the rays in the tangential and sagittal planes focus at one point. The entrance slit operates as a one-dimensional aperture to obtain high spectral resolution.

The paper presents an approach to the design and development of the optical head of the star tracker and its hood for satellites. The main stages of the optical system design including development of requirements, selection of the optical system by analyzing with help of CAD, hood design with help of simulation, as well as the main stages of its components(lenses) manufacturing and control of quality of manufacturing the optical system are described. Engineering model of the optical head of star tracker which can be used as the basis for the development of the star tracker prototype for use in Kazakhstan's satellites was developed in accordance with the requirements.

Plastic optical fiber level measurement sensor based on in-line side holes is investigated theoretically and experimentally. The sensor consists of a plastic optical fiber with in-line side holes spaced about 5 cm apart. The 0.9 diameter in-line side holes were fabricated by micro-drilling. An analytical expression of the sensor transmittance was obtained using a simple ray optics approach. The measurements of the sensor transmittance were performed with a 55 cm height Mass cylinder. Both results show that the sensor transmittance increases as the number of side holes filled with water increases. The research results indicate that the plastic optical fiber based on in-line side holes can be used for water level measurement.

Bar chart patterns projects by collimator was adopted to measure contrast transfer function (CTF)values at Nyquist frequency before assembly of imaging sensor with telescope for earth-observing pushbroom imager. A relay imaging probe consisting of optical objective and 2D imaging sensor was builded to image these projected pattern and estimate the image quality of optical system before alignment of linear imaging sensor. By riding on a hexapod stage and measuring at a series focus position at several field angles, this probe provides a reference map for alignment of imaging sensor and image quality assessment. Certainly, testing result can be used to anticipate result of focusing alignment.