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ALOS-2, the next-generation Japanese SAR satellite, is designed to perform autonomous precise orbit control of Earth-referenced repeating orbits for effective repeat-pass SAR interferometry. The orbit control accuracy requirement of ALOS-2 is 500m (95%) with respect to the reference Earth-fixed flight path. This accuracy is guaranteed for all latitudes by not only drag-makeup maneuvers but also frequent...
The main objective of this research is to investigate the possible use of synthetic aperture radar (SAR) data to monitor sea ice in the southern region of the Sea of Okhotsk. There are a lot of SAR satellites operating in orbit, and most satellites can observe the ground targets with various observation parameters. We would like to find out the suitable observation parameters for monitoring sea ice...
Low-Backscattering area extraction is important to oil spill, vessel detection or other object recognition. In this paper, we proposed a novel algorithm for low-backscattering extraction in high-resolution SAR images, which combines histogram thresholding and classification. In each sub window the presence of dark areas was determined based on features derived from non-supervised classification. The...
Permanent Scatterer SAR Interferometry (PSInSAR) algorithm identifies coherent radar targets (PS) to detect and monitor surface deformation phenomena. PS typically correspond to point-wise, man-made objects widely available in urban areas. Sometimes, however, it is difficult to apply this technology for un-urban areas, due to a much lower spatial density of PS. To overcome the limit of PSInSAR and...
Because of the target scattering characteristics are unpredictable, AD Converter is saturated sometimes. Typically, AD Converter saturation distortion is considered as a noise which is similar to quantization. the power of AD Converter saturation equal to the square value of the difference between input analog value and the reconstruction digital level. However, the effect of AD Converter saturation...
Satellite-based optical imagery has been widely used to evaluate coastal erosion. However, it is difficult to define shoreline edges because the sand under seawater near the shoreline can often be seen in clear water in optical images. Synthetic aperture radar (SAR) images have the potential to be used to interpret the boundary between a sandy beach and seawater because of the unique characteristic...
The global warming may affect the cryospheric environment and many reports showed the retreat of glaciers, thinning of ice shelves and ice sheet on Antarctica. Retreat of mountain glaciers also might be explained in the same context. This paper aims to show how useful the ALOS / PALSAR data for cryospheric applications through the case study of two typical areas, one is rock glacier monitoring on...
Multi-channel Synthetic Aperture Radar (SAR) system is of great interests for many applications, such as the ground moving target indicator (GMTI). However, one of the challenging problems for GMTI using multi-channel SAR system is the spectrum aliasing in azimuth dimension which could lead to ghost target after imaging. In this paper we present a method to suppress the ghost target by using phase...
In this paper, we propose an advanced co-registration method for Interferometric Synthetic Aperture Radar (InSAR). Previously, we proposed a sub-pixel scale coregistration method which employs the number of singular points (SPs) and the amplitude information as the evaluation criterion (SFS-SPEC method). To improve the accuracy of the co-registration, here we propose to create a reference interferogram...
This paper summarizes the calibration and validation results of the JAXA's new airborne polarimetric interferometric L-band synthetic aperture radar, i.e., Pi-SAR-L2, developed in 2011–2012 and started the operation in April of 2012. Pi-SAR-L2 is enhanced for the radiometric and geometric performances with 85MHz bandwidth and the accurate Inertial Navigation System. Polarimetric and geometric calibration...
We are developing a low-cost radar altimeter for terrain-aid navigation application. The position estimator is properly designed understanding the limitation of the altimeter range measurement system. Our initial study reveals that conventional wide-beam altimeters or non-interferometric SAR-based altimeters work well with the non-linear estimator that propagates the probability density functions...
Differential SAR interferograms map the ground displacements with high spatial resolution. Many signals of interest, for example, those due to earthquakes and volcanic activities, are spatially correlated and are often obscured by artifacts caused by tropospheric and ionospheric fluctuations, inaccurate orbit data, and errors in the digital elevation model. In this study, a method to correct for such...
The azimuth multichannel is incorporated into BS-SAR (spotlight SAR, sliding spotlight SAR or TOPS SAR). The signal reconstruction algorithm used for multichannel stripmap SAR may not be effective for multichannel BS-SAR (MC-BS-SAR). In this paper, a multichannel full-aperture azimuth processing algorithm is proposed for a BS-SAR. With this method, the azimuth spectrum of multichannel signal can be...
This paper presents a 2nd order motion compensation (MoCom) algorithm for squinted spotlight synthetic aperture radar (SAR). A precise compensation of the range-dependent components of the motion error is indispensable for high-resolution SAR systems. Besides, the MoCom has to be compatible with an accurate focusing technique - the Omega-K algorithm in this case. After a proper bulk MoCom and a range...
The SlimSAR is a flexible, multi-frequency band, multi-mode synthetic aperture radar system with options suitable for operation on aircraft across a wide range of size and capabilities. From small unmanned aircraft flying at low altitude and covering a small area, to large aircraft covering very wide swaths, the SlimSAR has the versatility to perform in any mission scenario. One application is that...
This report introduces a new 3D terrain information reconstructing application software for airborne interferometric SAR. This application enables (1) semi-automation of the reconstruction processing sequences and rapid availability of outcome as a consequence, and (2) composition of DEMs generated from data with different observation angles so that more information can be obtained. An outline of...
This research aims to analyze tropical forest loss between 2007–2030 using L-band SAR data and a spatial explicit model with multiple what-if scenarios. Annual time series PALSAR data from 2007 to 2010 were analyzed for forest mapping and detecting land cover changes in Riau Province of Central Sumatra, Indonesia. A spatial model was calibrated and validated using the Markov Chain, Bayesian, and fuzzy...
This paper shows the challenges in analyzing the growing stages (i.e. tree age) of the forests in Oita Prefecture, Japan, by using the L-band ALOS PALSAR remote sensing data. A polynomial model was applied to estimate the stem volume information of the forests and the volume information was then inverted to the tree age information using the forest inventory table provided by the Oita Prefectural...
This paper explores the frequency dependency of polarimetric properties of SAR backscatter from Arctic sea ice. The study focus on L and C-band full polarimetric SAR (PolSAR) data from the Beaufort Sea, collected by the NASA/JPL AIRSAR system in December 2004. An area showing various types of first year ice, plus regions of multi-year ice, is selected for a polarimetric analysis, which included a...
With the increase in the global demands for food and bio-fuels, the plantation area is increasing and they are the major derivers of deforestation and biodiversity loss in Southeast Asia. A number of research papers have demonstrated the applicability of Synthetic Aperture Radar (SAR) data to monitor terrestrial ecosystem in tropical countries without limitations of clouds. This study investigated...
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