Comparison of Atmospheric Phase Delay on ALOS PALSAR Interferogram and Cloud Distribution Pattern on Simultaneously Observed AVNIR-2 Images

Tropospheric artifact is a serious problem for detecting crustal deformation using differential synthetic aperture radar intereferometry (DInSAR) technique. Advanced Land Observing Satellite (ALOS) has capability for simultaneous observation between synthetic aperture radar, PALSAR and optical sensor, AVNIR-2. We compared ALOS PALSAR interferogram with simultaneously observed AVNIR-2 images. Nominal spatial resolution of AVNIR-2 is sufficient for valuation of PALSAR interferogram. Terra/Aqua MODIS images are compared with PALSAR interferogram and cloud top heights is estimated. Test site is Miyagi prefecture where one of the most active seismic zone in Japanese islands. AVNIR-2 images show the two types of clouds pattern that causes interferometric phase delay. The first is lee wave cloud which shows the presence of gravity waves. The second is thick cloud as cumulus which is formed by condensation of water vapor. An interferogram show combination of phase delays in a couple of data. Simultaneously observed AVNIR-2 image is possible to use for evaluation of PALSAR interferometric fringe patterns.