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Polarimetric signatures of oyster reefs in tidal flats were investigated using multi-frequency polarimetric SAR data. The scattering mechanism in tidal flats was analyzed by the Freeman-Durden target decomposition and the target depolarization effect was quantitatively measured using the cross-polarized ratio. Strong multiple scattering and depolarization effect were observed in oyster reefs areas...
The main objective of this research is into the possible use of synthetic aperture radar (SAR) data to monitor sea ice especially in the southern region of the Sea of Okhotsk. There are a lot of SAR satellites operating in orbit, and most of satellites can observe ground targets with various observation parameters. We would like to find out the suitable observation parameters for monitoring sea ice...
In this paper, we investigate the potential of large-scale mosaics of Synthetic Aperture Radar (SAR) data for land cover mapping. The study is based on a wall-to-wall mosaic of double-polarization data (HH and HV) from the L-band sensor PALSAR, covering the whole African continent at a spatial resolution of about 100m. The GlobCover 2009 global land cover map is taken as a reference for the training...
Forest biomass is important information for the forest management and the studies of global changes. Researches showed that SAR data is superior in the estimation of forest biomass. However the backscattering coefficients are not the direct measurements of forest biomass. It can be affected by forest canopy spatial structures. In this study, eight scenes of PALSAR data acquired from July 10th 2007...
Backscattering of a microwave signal is considered in the Kirchoff approach and in two-scale model of the scattering sea surface. The effective reflection coefficients in Ku (0.021 m), C (0.055 m), and S (0.09 m) bands are calculated. Dependences of the radar cross section on wind speed, wind fetch, and swell height are studies and closeness of numerical estimations and experimental data is shown...
Scatterometric wind retrieval based on HH- or VV-pol. radar backscatter experiences saturation at high winds, whereas recent measurements demonstrated that the cross-polarized signal, VH- or HV-pol. at high winds shows a strong dependence on wind speed. Explanation of such a behavior of the cross-polarized microwave radar from a theoretical standpoint represents a challenge. A classical composite...
Efficient estimation of the interferometric phase and complex correlation is fundamental for the full exploitation of SAR Interferometry capabilities [1]. Particularly when combining interferometric measures arising both from distributed and concentrated point targets, the interferometric phase has to be correctly extracted in order to preserve its physical meaning and respect the homogeneity hypothesis...
A Fresnel Double Scattering (FDS) method is presented in this paper to accurately and efficiently calculate the backscattering cross sections from two tree branches in the Fresnel zone of each other. The branches have a comparable size to the wavelength for L band frequencies in length and in radius. It is demonstrated that the FDS results provide a good approximation to the exact solutions where...
The potential of TerraSAR-X (X-band) in monitoring sugarcane growth was investigated on Reunion Island. Multi-temporal TerraSAR data acquired at various incidence angles (17°, 31°, 37°, 47°, 58°) and polarizations (HH, HV, VV) were analyzed in order to study the behaviour of SAR (synthetic aperture radar) signal as a function of sugarcane height. The potential of TerraSAR for mapping the sugarcane...
The ESA funded campaign BioSAR 2010 was carried out at the forestry test site Remningstorp in southern Sweden, in support to the BIOMASS satellite mission under study. Fully polarimetric SAR data were successfully acquired at L- and P-band using ONERA's multi-frequency system SETHI. In addition with other data types gathered, e.g. LiDAR and in-situ measurements, the compiled data set will be used...
This paper studies the identification of inland transient water bodies using an L-band radar, especially the dependence of the identification accuracy on the radar measurement noise (noise-equivalent radar backscatter, σNE0). The different levels for the radar measurement noise are simulated using the images taken by the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR). With the original...
This paper proposes a new polarimetric Synthetic Aperture Radar (PolSAR) calibration method that applies an incoherent decomposition model to the uncalibrated covariance data measured for the forest and surface, and determines the polarimetric distortion matrix (PDM). The Freeman-Durden model [1] is used to express the polarization dependent signal reflection from and penetration through the forest...
Monitoring of snow cover is crucial to the study of global climate changes, for water resource management, as well flood and avalanche risk prevention. The sensitivity of X-band backscattering of Cosmo-Skymed mission has been first exploited by using model simulation and experimental data. An algorithm for retrieving snow depth or snow water equivalent has been then developed and test with experimental...
The acquisition of Snow Water Equivalent (SWE) at spatial resolutions higher than those of the present methods relying on inversion of coarse-scale passive microwave observations is a possible application for space-borne SAR imagery. The presented experimental campaign NoSREx (Nordic Snow Radar Experiment) was initiated to contribute to the knowledge of snowpack backscattering and emission properties,...
ALOS PALSAR uses L band which is related with volume scattering. The volume scattering is the reflection comes from the surface and the inside of canopy. Forest management activities can be monitored using PALSAR L-band for Reducing Emissions from Deforestation and Forest Degradation (REDD). But it is still unknown how the biomass changed by the thinning (forest management) influences the backscattering...
Soil moisture retrieval from SAR data presents two main sources of uncertainty: terrain heterogeneity and speckle noise. In this paper, these issues will be addressed by using a Bayesian approach. Such a Bayesian approach (1) needs only a forward model (no retrieval model required), (2) gives the optimal unbiased estimator for the soil moisture and its error and (3) can include as many error sources...
In this paper, we study the radar retrieval of soil moisture and canopy parameters in a forested area. The forward model is a discrete scatterer radar model and the inverse model implements a global optimization scheme known as simulated annealing. Inversion is first applied to synthetic data assuming hypothetical allometric relationships to make the retrieval possible by reducing the number of unknowns...
In the southwest of China, Synthetic aperture radar (SAR) is anticipated to provide an important tool for forestry inventory because of its all weather capabilities. In this paper, Zhazuo area in Guizhou Province of southwest China, with typical Karst landform, was selected as the test site, and six RADARSAT-2 polarimetric images were used for experiments. Methods for forest mapping based on polarimetric...
PASCO in approximately 4 years, after the launch of TerraSAR-X (TSX), has successfully carried out a total 22 studies of disaster response for the worldwide and domestic cases. The outline and a part of the conducted cases are explained in detailed in this paper.
A new biomass retrieval algorithm based on P-band multi-polarization backscatter has been developed and evaluated based on SAR and ground data over boreal forest. SAR data collections were conducted on three dates at a test site in southern Sweden (Remningstorp, biomass < 300 tons/ha; late winter to early summer 2007) and on a single date at a test site in northern Sweden (Krycklan, biomass...
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