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Target image database is of great significance in SAR automatic target recognition (ATR). Recently, some convenient and low cost approaches of database simulation were proposed. However, the similarity between virtual SAR images obtained by these simulation approaches and real SAR images is still under study. To solve this problem, we will model the virtual target with three-dimensional (3D) modeling...
An algorithm to simulate the reflectance of clouds using visible bands was developed based on the simplified radiative transfer equation and two assumptions. The assumptions and algorithm were evaluated using a Landsat 8 sub-image of 015/035 (path/row) acquired on 27 August 2013. The relationship of visible bands in clear regions was verified to be linear. The effects of clouds in visible bands were...
The distorted Born approximation (DBA) combined with the numerical solutions of Maxwell equations (NMM3D) has been used for the radar backscattering model for NASA's Soil Moisture Active Passive (SMAP) mission. The models for vegetated surfaces such as wheat, grass, soybean and corn have been validated with the Soil Moisture Active Passive Validation Experiment 2012 (SMAPVEX12) data. In this paper...
In this paper, a sub-pixel mapping (SPM) method based on super-resolution then spectral unmixing (SRTSUSPM) is proposed. In the proposed framework, firstly projection onto convex set (POCS) model with the endmembers of interest is applied to original imagery to obtain a high-resolution imagery; then the fraction images are derived from the high-resolution imagery by linear spectral mixture analysis...
In geosynchronous (GEO) synthetic aperture radar (SAR), the high orbit height and the long integration time would lead to the significant round-trip delay time and the curved flight path, thus the traditional range model with ‘stop-go’ assumption will be ineffective. In this Paper, based on the analysis of instantaneous Doppler frequency of GEO SAR, an equivalent midpoint mathematical model is proposed...
In this paper, the blind restoration of a degraded image with an auxiliary image from another sensor is considered. In a typical multispectral satellite imaging system, multiple images from different sensors of the same area are available. When one of those images in a multiple image set is degraded, another image in the set can be used as a prior image for restoration. A hybrid algorithm based on...
GF-3 is the Chinese Synthetic Aperture Radar (SAR) satellite mission with scientific and commercial applications, which will be launched in 2016. The ortho-rectification image combined with the DEM data can only be satisfied with the applications of the high resolution radar image, the data quantity with wide-breadth also put forward higher request to the automation processing. The Reverse-Range-Doppler...
The grounding line (GL) is the location where ice sheet lose contact with the bed rock. Since this line is under the surface ice, it's hard to define the GL. However, the different basal condition besides the GL caused different vertical movement and a flexure is often formed at the GL. This flexure is detectable by optical images. Meanwhile the ocean-induced vertical movement is detectable by repeat...
Global Navigation Satellite Systems Reflectometry (GNSSR) is a sort of multi-static radar using navigation signals as signals of opportunity. Due to the large number of transmitting satellites multiple scattering points over the Earth's surface can be simultaneously tracked, which provides wide-swath and improved spatio-temporal sampling over current space-borne radar altimetry missions. The lack...
Synthetic Aperture Radar (SAR) has been developing from single-working mode to multi-working model. And the antenna pattern becomes hundreds and thousands, which causes a huge burden on radiometric calibration. Using antenna models to replace the measured antenna patterns in radiometric calibration can greatly simplify the calibration duties. This paper tries to find the relationship between antenna...
This paper investigates the deployment of multi-tethered InSAR system applied in GMTI missions. Since the baselines for GMTI are usually short, the tethers whose length is almost identical to the baselines are short as well. As a consequence, the deploy mechanism should not work under this condition to avoid the unsuccessful deployment caused by the output error of the mechanism. Hence, the free deployment...
Forest vertical canopy cover (VCC) is an essential factor to be considered during forest resource inventory, sub-compartment division and thinning intensity. In order to monitor the forest canopy structure changes over the Greater Khingan, two temporal (2005 and 2010) forest VCC are derived by inverting the Li-Strahler geometric-optical model (GO) based on the extracted endmembers. The results show...
Using spectral of broadband emissivity which was measured by Fourier Transform Infrared spectrometer (FTIR) over Taklimakan Desert and MODIS data, we developed an empirical regression equation to estimate the surface broadband emissivity for the spectral domains 8–13.5 µm by the MODIS data. The accuracy of the equation was verified by the observed FTIR data and the MODIS spectral library data, respectively...
Improved soil moisture estimation, within a combined radar-radiometer framework, by using Joint-physics modeling is demonstrated and presented in this work. Detailed numerical simulation on bare, but rough surfaces, highlight how improved emission-scattering modeling, can outperform conventional approaches. Root-mean-squared error statistics show almost a factor of two improvement in soil permittivity...
An algorithm has been developed for retrieving instantaneous microwave land surface emissivity using brightness temperature and precipitable water vapor data. Unlike previous algorithms, the new technique does not need infrared land surface temperature as the input data, and overcomes the limitation of previous algorithms under cloudy conditions. Compared with the values from physical retrieval algorithm,...
In this study, we used a multilinear regression approach to retrieve surface soil moisture from NASA's Soil Moisture Active Passive (SMAP) satellite data to create a global dataset of surface soil moisture which is consistent with ESA's Soil Moisture and Ocean Salinity (SMOS) satellite retrieved surface soil moisture. This was achieved by calibrating coefficients of the regression model using SMOS...
A fundamental requirement for coherent processing of repeat pass SAR data stacks is to have precise knowledge of the relative position of each track. Indeed, sub-wavelength position errors give rise to residual phase screens among different passes, which hinder coherent applications. In this paper we describe an approach to estimate and remove phase screens by exploiting distributed targets, based...
We prove the possibility of creating a temperature dependent multi-relaxation spectroscopic dielectric model (TD MRSDM) for a set of organic soil containing 50% (Yamal tundra), 80% (Alaskan tundra) and 90% (boreal pine litter) of organic solids. The created model is based on the previously developed TD MRSDM for the Yamal tundra soil complemented with specific temperature dependences for the hydrological...
It is the basis of realization ship recognition to accurately extract geometric parameters of the ship target in synthetic aperture radar (SAR) images. Due to the unique SAR imaging mechanism, speckle noise, azimuth ambiguity and side lobe effect seriously impact on geometric parameter estimation of the ship target. Therefore, a method is presented to extract geometric parameters of the ship based...
The aim of this study was to estimate soil moisture from RADARSAT-2 Quad-polarization Synthetic Aperture Radar (SAR) data acquired in the agricultural areas. The adopted approach is based on the combination of semi-empirical Water-Cloud model and Dubois model. Firstly, VH backscattering coefficient was used to develop empirical relationship for crop water content estimation. Secondly, crop water content...
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