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Optical instruments for space applications are rather delicate subjects as customer demands are typically high in terms of performance and environmental conditions are harsh. For the development of such systems a highly integrated engineering team consisting of specialists from various technical disciplines is mandatory as thermal, structural and optical properties are impacting directly the imaging...
UrtheCast is currently developing advanced technology for its OptiSAR™ Constellation that comprises 8 tandem pairs of SAR and Optical Satellites in two orbit planes. The OptiSAR™ mission represents a capability shift in both spaceborne remote sensing and imagery exploitation.
Reliable information on snow cover across the Northern Hemisphere and Arctic and sub-Arctic regions is needed for climate monitoring, for understanding the Arctic climate system, and for the evaluation of the role of snow cover and its feedback in climate models. In addition to being of significant interest for climatological investigations, reliable information on snow cover is of high value for...
Sea surface temperature (SST) images taken from satellites are partially occluded by clouds. In this paper, we propose an inpainting approach for restoration of the partially occluded images. Assuming the sparseness of the SST images, we employ a learning based inpainting for filling the occluded parts. Images taken in the past several days is another clue for filling the occluded parts. These images...
Quantum key distribution (QKD) has raised increased attention over the past years as one of the most attractive quantum technologies for practical implementation. QKD has already been implemented in intra-city networks all around the world. But up to now, bridging global distances with quantum communication remains an outstanding challenge. A promising candidate to provide this link is via optical...
To improve the accuracy of satellite signal propagation, we designed a moving-window finite-difference time-domain (FDTD) method, in which the distribution of the electron density given in IRI-2007 model was used, and calculated the time-delay for a uniform distribution of the electron density to prove the validity, the calculated result fitted the theoretical result. So it is proved our FDTD method...
In this paper, More than 1000 satellite images including Terra/Aqua MODIS, Sentinel-1A SAR images from 2013 to 2015 were analyzed to obtain spatio-temporal distribution of internal waves in the Andaman Sea. The statistical results demonstrate that the internal wave have been observed mostly in four areas by the remote sensing: northern Sumatra Island, western Malay Peninsula, northeast of the Nicole...
In this paper we present a study on the use of remote sensing data combined to the 3D modeling of radiative transfer (RT) and energy balance in urban canopies in the aim to improve our knowledge on anthropogenic heat fluxes in several European cities (London, Basel, Heraklion, and Toulouse). The approach is based on the forcing by the use of LandSAT8 data of a coupled radiative transfer model DART...
The main objective of this study is to develop an inversion technique based on neural networks to estimate soil surface moisture and leaf area index (LAI) in irrigated grasslands by combining fully polarimetric RADARSAT-2 C-band SAR and optical data (LANDSAT). The benefits of having data in dual-polarization or in full-polarization mode for the SAR images were evaluated in comparison to the single-polarization...
We describe here the basic concepts for an operational system for deriving water depth and sea bottom albedo from high resolution multispectral satellite images. The uncertainties in depth derived from different satellites and at different time are examined. The uncertainty is generally within 20% of the depth value.
Ship target detection in optical remote sensing images has attracted more and more attention in the field of remote sensing. The ship target detection technology of optical remote sensing images is vulnerable to many factors, while the real data are difficult to contain various elements. In order to obtain the various situations in the large sea scenes, we develop a simulation system for high-resolution...
In this work, X and C band images acquired by COSMO-SkyMed (CSK) and Sentinel-1 (S1), respectively, on alpine environment have been compared for investigating snow characteristics. The specific capabilities of each sensor, involving also optical sensors (i. e., Landsat and Sentinel-2 satellites), have been exploited. Dense Media Radiative Transfer theory, with quasi-crystalline approximation (DMRT-QCA)...
We investigate the error performance of a satellite-to-ground optical link between a low-earth orbit (LEO) satellite and an optical ground station (OGS) in which a geostationary orbit (GEO) satellite is used as a relay. We perform a bit-error probability (BEP) analysis by taking the atmospheric turbulence effects and pointing errors into account. We use pulse position modulation (PPM) and consider...
We investigate the error performance of a satellite-to-ground optical link between a low-earth orbit (LEO) satellite and an optical ground station (OGS) in which a geostationary orbit (GEO) satellite is used as a relay. We perform a bit-error probability (BEP) analysis by taking the atmospheric turbulence effects and pointing errors into account. We use pulse position modulation (PPM) and consider...
We evaluate the bit error rate (BER) performance of a geostationary earth orbit (GEO) satellite to earth free space optical (FSO) link using intensity modulated/direct detection (IM/DD) system. The analysis is carried out in presence of turbulence and various weather conditions. The combined channel state probability density function (pdf) is obtained by using gamma-gamma distribution to model the...
Optical characterization of space objects generally involves the observation of an object of interest as it passes over a ground-based imaging asset. Owing to the presence of turbulence, adaptive optics, post-processing, or a combination thereof, is used to enhance imagery. Specular glints, often present in such imagery, can introduce severe artifacts after post-processing methods are applied. Removing...
This paper describes a relative orbit estimation method for the close distance flyby adjacent to small bodies such as asteroids, comets, and natural satellites. Previous studies showed that, in a high-speed relative velocity flyby or a close distance flyby of small astronomical bodies, typical estimation algorithms such as a linear batch processing and an extended Kalman filter are no longer applicable...
The application of an integrated monitoring tool to assess and understand the effects of annually occurring forest fires is presented, with special emphasis to Mediterranean and Temperate Continental zones of Europe. The distinctive features of the information conveyed by optical and microwave remote sensing data have been firstly investigated, and pertinent information have been subsequently combined...
In collaboration between CNES, NICT, Geoazur, the first successful lasercom link between the micro-satellite SOCRATES and a non-Japanese OGS has been established. This paper presents some results of telecom and scintillation first data analysis for 4 successful links in June & July 2015 between SOTA terminal and Meo optical ground station (OGS) at Caussols France. The telecom and scintillation...
Space optical communications is studied at National Institute of Information and Communications Technology, where the Small Optical TrAnsponder (SOTA) was developed and embarked on a 50-kg-class satellite. Atmospheric fluctuation is an issue to be solved in ground-to-satellite optical communication links. The SOTA has error-correcting functions using Reed–Solomon code and low-density generator matrix...
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