Airborne laser bathymetric system has great advantages in shallow sea bathymetric mapping due to its no blind area, high accuracy and high density data. By using Monte Carlo method and radiation-transport equation, the spatial distribution of the signal spot on the sea surface is calculated respectively. The results show that the spatial distribution of the signal spot returned to the sea surface is more extensive with the increase of the depth, and the power attenuation of the center of the spot is more serious. In this paper, signal to noise ratio (SNR) is used as the performance evaluation criterion of laser bathymetry system, and the requirements of field of view for signal detection under different depth are analyzed. The analytic results will provide support for the design and optimization of the laser bathymetric system.
Space gravitational wave detection, extraterrestrial life exploration and high-precision measurement of earth's gravity field have great scientific significance and wide application value. Inter satellite long baseline high-precision laser interferometry ranging technology can obtain high-precision inter satellite displacement variation, which is the key technology of the above space-based scientific engineering. The laser interference system transforms the inter satellite displacement into corresponding interference signals. The above-mentioned scientific plan has put forward extremely high precision, stability and wide bandwidth requirements for laser interference phase measurement. It can be seen that the high-precision laser phase measurement technology has become the bottleneck to further improve the ranging accuracy and stability. This paper researches the progress of high-precision laser phase measurement technology for space-based precision ranging at home and abroad, analyzes the demand of this technology in space-related fields and proposes the key technologies and preliminary schemes to be solved in the research.
The earth’s gravity field reflects the spatial distribution, movement and change of the earth’s mass. High precision gravity field is one of the main tasks of geodesy. The feasibility research of future China's satellite gravity mission(CSGM) were carried out, the satellite to satellite tracking in the low low mode was selected in the future satellite gravity measure. A precise laser ranging system is a key component to CSGM. In this paper, a laboratory breadboard heterodyne laser interferometer was built, experimental result demonstrated that laser ranging performance in laboratory distances was 1 nm@0.01Hz and below1nm@1Hz in translation measurement, and can meet the demand of CSGM mission.
Based on the requirements of project assignment, the paper firstly introduces the needs for principle prototype, and its overall technical solutions, assignment analysis and requirement index. Then it elaborates key technical solutions, prototype technical plan, as well as project design and production of its components, besides, we also developed testing device for debugging and testing needs, when the components design is completed, we conducted components alignment and testing, overall testing, obtaining noise squeezing degree (dB)of quantum squeezed field by principle prototype ≥ 6.4 dB, and the resolution higher than 0.2 mm @ 0.5m. We met the index requirements of principle prototype and realized high resolution imaging, providing significant basis for the following relative projects and for the development of new remote sensing technology with high performance.
Squeezed state light field can surpass the shot noise limit and improve the signal-to-noise ratio of the sensor measurement. In this paper, based on optical parametric amplification (OPA), we present employed a semi-monolithic cavity and miniaturization design of optical parametric amplifier (OPA) to improve system stability. The infrared spectrum 1064nm quadrature squeezed state field of noise squeezing degree 6.75dB is obtained by pumped the PPKTP crystal via 532nm laser. This work provides a practical light source for quantum sensing detection.
According to remote sensing science and technology development and application requirements, quantum remote sensing is proposed. First on the background of quantum remote sensing, quantum remote sensing theory, information mechanism, imaging experiments and prototype principle prototype research situation, related research at home and abroad are briefly introduced. Then we expounds compress operator of the quantum remote sensing radiation field and the basic principles of single-mode compression operator, quantum quantum light field of remote sensing image compression experiment preparation and optical imaging, the quantum remote sensing imaging principle prototype, Quantum remote sensing spaceborne active imaging technology is brought forward, mainly including quantum remote sensing spaceborne active imaging system composition and working principle, preparation and injection compression light active imaging device and quantum noise amplification device. Finally, the summary of quantum remote sensing research in the past 15 years work and future development are introduced.
Imaging spectropolarimetry has been explored as a method that increment in our capability to respond to existing requirements, as well as to our insatiable need for more information in remote sensing applications. Spectrometry enables detailed comparison of target and background spectra. The polarimetric state of received radiation contains valuable information about source object surface roughness and orientation, it has the potential to highlight manmade objects despite spectral camouflage. A laboratory breadboard spectropolarimetric system has been design for operation in the visible waveband to demonstrate the potential of this technique for future airborne and spaceborne systems. The experiment setup and some experimental results are presented in this paper.
There has been much recent interest in quantum technology for applications to high resolution imaging and interference measurement. Due to noise and photon loss in the transmission between the telescopes, the current optical interferometers have quite limited baselines to a few hundred meters at most, which limit the resolutions. Here we propose to use noiseless linear amplifier (NLA) to reduce optical loss in the transmission. We also show that NLA can be further improved with local squeezing operator. We envisage that our analysis on this squeezing operator assisted NLA method could help to develop higher resolution interferometers, which would have many applications in stellar observation.
The summary of hyperspectral polarization remote sensing detection is presented, including the characteristics and mechanism of polarization detection, the expression of polarization light and the detection method. The present research of hyperspectral polarization remote sensing is introduced. A novel method of hyperspectral polarization imaging technique is discussed, which is based on static modulation adding with the double refraction crystal. The static modulation is composed of one polarizer and two retarders. The double refraction crystal is used to generate interference image. The four Stokes vectors and spectral information can be detected only by one measurement. The method of static modulation is introduced in detail and is simulated by computer. The experimental system is also established in laboratory. The basic concept of the technique is verified. The simulation error of DOP (polarization degree detection) is about 1%. The experimental error of DOP is less than 5%. The merits of the novel system are no moving parts, compactness and no electrical element.
A quantum-enhanced receiver that uses squeezed vacuum injection (SVI) and phase sensitive amplification (PSA) is in principle capable of obtaining effective signal to noise ratio (SNR) improvement in a soft-aperture homodyne-detection LAser Detection And Ranging (LADAR) system over the classical homodyne LADAR to image a far-away target. Here we investigate the performance of quantum-enhanced receiver in Λ-type soft aperture LADAR for target imaging. We also use fast Fourier transform (FFT) Algorithm to simulate LADAR intensity image, and give a comparison of the SNR improvement of soft aperture case and hard aperture case.
Squeezed light is an important non-classical light field. In this paper, we demonstrated a designed active imaging system
which use squeezed state light instead of coherent light as light source. The squeezed state light is generated by utilizing
the degenerate optical parametric amplifier based on periodically poled KTiOPO4 crystal. In order to obtain better
imaging results, microlens arrays are used for homogenizing the squeezed light. We describe experiment setup and
present some design result.
In this paper, a multi-port THz Fourier transform spectrometer is designed to measure Terahertz spectrum. Multi-port optical design make spectrometer more flexible used on pot light source and collimated light source directly, which eliminating the need of external conversion optical path for different light source, and also allows using a variety of external detectors flexibly, extending the spectrometer’s measured range. The Fourier transform spectrometer is described.
Spectropolarimetry is the technique that spectrally resolves polarisation properties of light. The conventional spectropolarimeter generally suffer from vibration, electrical noise, and alignment difficulty introduced by the mechanical or electro-optic device for polarization control, such as a rotating compensator and a liquid crystal device, such a polarization controlling element generally requires the considerable volume as well as the electronic driving cables, which has been the major obstacles for the reduction in the size of the spectropolarimeter. This paper presents a compact configuration of the channeled spectropolarimeter designed to increase the stability of the state of polarization measurement, the whole spectropolarimeter system without any internal moving parts, electrically controllable or micro-components, which enables us to determine all the parameters related to the spectral dependence of the state of polarization of light at once from a single measurement. In this spectropolarimeter system, multiple-order retarders are utilized to generate a channeled spectrum carrying information about the wavelength-dependent multiple parameters of polarization of light. The theory analysis and some aspects of our proof of concept experiments are given in this paper.
Polarization hyperspectral imagers combine polarization technology, spectral technology and imaging technology, get both the image of the target and the polarization and spectrum of the pixel to recognize the materials on the objects,have broad applied foreground on airborne remote sensing domain. That arrests extensive attention abroad.
This paper brings hyperspectral technology and polarization image together. On the basis of geometrical optics theory
and polarization theory, puts forward a new polarization hyper-spectral Imaging technology. That could get hyper-spectral information and whole Stokes elements spectral from the object on the measuring the power spectral from
the modulator only one time, and that raise the ability of recognization greatly. The paper carries out a project to the new airborne polarization hyperspectral imager.
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.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
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.