Toshihiko Umehara

Learn More
This paper discusses the polarimetric correlation coefficient to extract the urban areas from polarimetric Synthetic Aperture Radar (POLSAR) image. For classification of POLSAR image, several methods have been proposed to extract polarimetric feature, such as Polarimetric Entropy-Alpha, three-component scattering model, Huynen parameters and so on. However,(More)
A 9.0-magnitude earthquake occurred off the pacific coast of Tohoku area of Japan, in March 2011. Accompanied with the subsequent tsunami, it caused a lot of casualties and damages in the coast area. We conducted urgent observations of the damaged areas with an airborne X-band SAR system, Pi-SAR2, immediately after the earthquake, on March 12 and the(More)
These days, the space-borne SAR becomes one of the powerful instruments to observe the earth surface. On the other hand, a airborne SAR is also important for development of SAR system and analysis technique. Moreover, airborne SAR is able to make immediate observation of disaster area. The National Institute of Information and Communications Technology(More)
1. Introduction This paper discusses the polarimetric correlation coefficient to extract useful feature from polarimetric Synthetic Aperture Radar (SAR) data. Several methods have been proposed to extract polarimetric feature, such as Polarimetric Entropy-Alpha, three-component scattering model, Huynen parameters and so on
NICT (National Institute of Information and Communications Technology, Japan) have developed a high performance airborne SAR system (Pi-SAR2) since 2006, as a successor to the Pi-SAR (X-band). Pi-SAR2 has polarimetric and interferometric functions with high spatial resolution of 0.3–0.6 m in along track (azimuth) direction and 0.3–0.5 m in(More)
In the National Institute of Information and Communications Technology, Japan (NICT), we have developed an advanced X-band airborne synthetic aperture radar (SAR) system, Pi-SAR2, since 2006, to succeed the X-band polarimetirc and interferometric airborne SAR, Pi-SAR. The Pi-SAR2 has a higher spatial resolution of 0.3–0.6 m in the azimuth direction(More)
The National Institute of Information and Communications Technology (NICT) developed an airborne X-band SAR system (Pi-SAR2: polarimetric and interferometric SAR 2) to monitor the earth's environment and disasters [1]. Pi-SAR2 has polarimetric and interferometric functions with high spatial resolution of 0.3m [2]. In this paper we describe the single-pass(More)
The synthetic aperture radar (SAR) has been utilized for monitoring natural disaster areas because the SAR observation can be performed irrespective of the daylight and weather conditions. To reduce the time from observation to distributing SAR images to the headquarters for disaster control and disaster area, we have developed an onboard processor which is(More)
To detect the moving targets such as cars or ships, we developed along-tack interferometric SAR (AT-InSAR) system and added its function on NICT airborne SAR. Our AT-InSAR can measure the moving targets in the single (VV) and dual (VV and VH) polarization. The dual polarization mode has more degree of freedom compared to the single polarization mode. The(More)