Scintillation Parameter Measurement via Amplitude Stripes in SAR Images

The scintillation stripes have been frequently captured in numerous acquisitions of the Advanced Land Observing Satellite (ALOS) Phased Array-type L-band Synthetic Aperture Radar (PALSAR). Even though the amplitude stripes can impede the SAR imaging and interferometric applications, the amplitude stripes can be beneficial for EPB sounding. In this study, a methodology that extracting the amplitude stripe pattern via normalized sub-band processsing and orientational filtering (NSB-OF) to measure the ionospheric scintillation parameters is proposed. First, a sub-band analysis is performed to suppress the ground scatter and sharpen the amplitude stripes. Second, the amplitude stripe is extracted in the NSB image through a band-rejection OF. Finally, the scintillation parameters, including scintillation strength C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</inf>L and spectrum index p are estimated. Another scintillation index S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> is then indirectly derived by the estimated C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</inf>L and p. The proposed methodology is applied to a group of PALSAR images with amplitude stripes and validated with the indirectly and directly measured S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf>. The results demonstrate that the NSB process has a high efficiency for the extraction of stripe pattern and measurements of scintillation parameters.