Mysterious stripes observed over amazon by the PALSAR onboard ALOS satellite
Abstract
From the analysis of all the images acquired by the Phased array type L-band SAR (PALSAR), which is a L-band synthetic aperture radar onboard Advanced Land Observing Satellite (ALOS) operational from May 2006 during April 2006 to December 2006, we found that several tens of images collected mainly in October, November and December of 2006 were interfered by the intensity variations, many small-width stripes along the satellite track, that are possibly caused by the ionospheric instability related to the disturbance of electron density due to the solar-earth daily interaction. The number of the interfered samples reaches to sixty, and all occurred in the nighttime in the Amazon. The interfered region reaches to 300km in east-west direction and 1000km or more in north-south direction. Since the width of the stripe is several hundred meters in range direction, the interference can be interpreted as phenomena that the ionospheric scintillation at the equatorial Amazon caused by the generation of the plasma bubbles that relates to the neutralization of the plasmatic atmosphere after the dark and their nonuniform diffuse. This stripe can be interpreted as the local TEC variation interfered the intensity of the SAR images. This is explained as the additive phenomena of two facts, 1) variation of the Total electron Contents (TEC) caused inuniformity of the refraction, and thus the ununiform compression of the image in range direction, 2) rotation of the polarimetric plane of the linear polarization L-band SAR caused by the number of the electrons density and the geomagnetic field. In this paper, we analyzed the several samples of this scintillation at the equatorial region, and obtain the quantitative TEC variation. As a result, it found that the PALSAR can measure the structure of the TEC distribution much more precisely than using the GPS.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFMSA33B1323S
- Keywords:
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- 0689 Wave propagation (2487;
- 3285;
- 4275;
- 4455;
- 6934);
- 2437 Ionospheric dynamics;
- 2471 Plasma waves and instabilities (2772)