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ALOS-2 ScanSAR data was used for examining the effect of precipitation and soil moisture variations on L-band forest backscatter in tropical regions. Multitemporal data spanning from observation cycle 39 to 62 acquired over tropical forests in South America and Africa has been used. Precipitation data provided through JAXA's global rainfall watch was used to examine the temporal change of L-band σ...
Time series PALSAR-2/ScanSAR data and Landsat data were used for examining the differences in detection timing of deforestation. Optical sensor-based (Landsat) deforestation information taken about every 16 days and SAR data taken about every 1.5 months were used, and the temporal change of L-band γ0 was examined for the deforestation areas. The γ0HH value increased by 1.2 dB on average for areas...
Recently many studies for application of multi-temporal interferometric SAR technique in monitoring ground motion have been reported. When we focus on number of scenes in high resolution mode of ALOS/PALSAR and ALOS-2/PALSAR-2, available number of scenes for interferometry are limited because of their global observation scenario. ALOS/PALSAR and ALOS-2/PALSAR-2 observation has been conducted with...
Land cover is an important earth observation parameter for understanding the Earth's ecosystem. Compared with optical sensors, Synthetic Aperture Radar (SAR) enables more rapid land cover monitoring with its all-weather, day-and-night imaging capability. We mosaicked 390 scenes of PALSAR-2 fully polarimetric data acquired in Japan and computed several polarimetric decompositions. Then, we applied...
The polarimetric characteristics of early- and late-stage deforestation areas were examined using PALSAR-2. An early-stage deforestation site, where the fallen trees had been left on the ground, showed an increase in σ0surface of 2.9 dB, and decrease in σ0volume of 1.4 dB. This induced the 0.9 dB increase in σ0HH. A late-stage deforestation site, where the fallen tree had been removed, showed an increase...
In 2016, the Advanced Land Observing Satellite-2 (ALOS-2, “DAICHI-2”) observed various disaster affected areas. Japan Aerospace Exploration Agency (JAXA) operated the emergency observation more than hundred times in the year. The Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) aboard ALOS-2 contributed for detecting the disaster affected area, ground deformation and flood affected area...
This paper introduces the operational status of the Advanced Land Observing Satellite-2 (ALOS-2) and its follow-on L-band SAR mission in Japan. ALOS-2 observes the earth surface with the Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) that is effectively used for many applications such as land deformation mapping and forest change mapping. To keep and enhance the applications using...
ALOS-2/PALSAR-2 25-m spaced global mosaic has been produced as the L-band SAR forest monitoring dataset selected from the best acquisitions over the global land and year 2014 and 2015, as the resume of the dataset after pausing the ALOS/PALSAR on 2011 April 22, in the end of 2015. Detailed evaluation results showed some image degradations compared to ALOS/PALSAR: visible stripes across the neighboring...
The PALSAR/PALSAR-2 contrast images are compared with the MODIS SST and Chl-a images. The comparison shows that the positions of line-shaped bright (ridge) patterns in the contrast images correspond with large SST gradients, i.e., SST fronts. Moreover, the comparison with the Chl-a image represents some local Chl-a maxima along the SAR ridge patterns in the PALSAR-2 contrast image, suggesting a general...
Decreasing the carbon emission from the deforestation and forest degradation is one of the issues that the humans need to tag for sustaining the Earth. Monitoring the forest from the space is the recent achievements that the space agencies contribute. Measuring the forest cover change is being conducted by using the high resolution optical and/or SAR images. ALOS-2 has been on-orbit carrying the L-band...
One of the main missions of the Advanced Land Observing Satellite-2 (ALOS-2, “DAICHI-2” ) is the disaster monitoring. Japan Aerospace Exploration Agency (JAXA) has operated the emergency observation more than hundred times in 2015. Not only the most important event in 2015, the Mw 7.8 Gorkha earthquake on April 25, the Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) aboard ALOS-2 observed...
The Advanced Land Observing Satellite-2 (ALOS-2) was successfully launched on 24th May, 2014. The mission sensor of ALOS-2 is the Phased Array type L-band Synthetic Aperture Radar-2 called PALSAR-2 which is the state of the art L-band SAR system. At After launch, the initial checkout and the calibration and validation phase had been completed, and the PALSAR-2 standard products were released via web...
The relationship between ocean wind vectors and L-band normalized radar cross sections (NRCS) is examined to modify the L-band geophysical model function (GMF) using the Phased-Array L-band Synthetic Aperture Radar 2 (PALSAR-2) and scatterometer wind data. The difference between the present study and previous one using the PALSAR is incidence angle range and polarimetry. Since the PALSAR-2 has a function...
Seasonal frozen ground and snow cover are sensitive indicators of how our home planet is changing. In the meantime, new spaceborne SAR systems have been launched, such as the polarimetric PALSAR sensor on-board ALOS in January 2006. In this paper, the relevance of L-band polarimetric SAR data for extracting cryospheric information is presented over lowlands. It is first demonstrated that dry snowpack...
ALOS-Next/Tandem-L is a proposal for a highly innovative L-band SAR satellite mission for the global observation of dynamic processes on the Earth's surface with hitherto unparalleled quality and resolution. It is based on a collaboration between DLR and JAXA which started with a pre-phase A study in 2013 and is currently undergoing a phase A study. Thanks to the novel imaging techniques and the vast...
Correlations between L-band SAR polarimetric parameters obtained with airborne SAR (Pi-SAR-L2) and metrics obtained with airborne LiDAR were examined to identify the relationship between the full polarimetric parameters and forest parameters obtained for a natural forest in Indonesia. Values of a0HV and a0VV show good correlations with canopy height and 90th percentile metrics of LiDAR, with R2 values...
In the field of Synthetic Aperture Radar (SAR) interferometry, we generally expect that there is only unique dominant scatterer in one pixel. To make a SAR interferogram, we have to observe a place twice. The dominant scatterer in every pixel must be identical in those observations. However, in an actual situation, there are multiple scatterers in one pixel physically, and the dominant one may be...
In this paper we introduce recent results of studies performed under the cooperated activities between Japan Aerospace Exploration Agency (JAXA) and the Agenzia Spaziale Italiana (ASI) for disaster monitoring. Under this cooperation, we performed simulation study of coordinated observation by ALOS-2, COSMO-SkyMed and other SAR satellites in case of huge Nankai Trough Earthquake in Japan. The result...
The relevance of this challenging still unresolved development of multi-band equatorially orbiting fully polarimetric POLinSAR satellite configurations to the entire terrestrial globe will be highlighted. Special attention will be given to generation of global weather phenomena, supply of an ever more relevant stable food base, extraction of mineral and energy resources with its implicit local environmental...
In this paper, we present the results of the stability assessment based on Interferometric Synthetic Aperture Radar (InSAR) for the active volcano. The stability of the lava is a quite important problem for the risk management. However, there are limited tools, especially in distant places, to analyze whether the lava will continuously spread or it will stop flowing. InSAR has been used for the deformation...
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