Mitigation of Ionospheric Noise in Azimuth Offset Based on the Split-Spectrum Method

The pixel-offset method has been utilized as a powerful tool to measure large ground movements. However, L-band spaceborne synthetic aperture radar (SAR) data are often affected by the ionosphere, which produces serious noises in azimuth component of pixel offset field, called streaks. Here, we propose new mitigate streaks based on physical modeling. Azimuth cannot be removed simply combining known relationship between ionospheric and phase delay with obtained split-spectrum method. Thus, taking into account that image matching (coregistration) affects measurement offsets, formulate theoretical correction formula subtracting coregistration-induced effects approximated polynomial function from offsets modeled using Applying two pairs Advanced Land Observing Satellite-2 (ALOS-2)/Phased Array type Synthetic Aperture Radar-2 (PALSAR-2) stripmap images severely demonstrate effective mitigation In application case no significant movement is detected Global Navigation Satellite System (GNSS), while standard deviation before 87.2 cm, value after 29.2 comparable accuracy offset. 2016 Kumamoto earthquake, substantially reduce successfully extract movements fields within an about 20 cm. result suggests proposed enables more accurate operational estimation 3-D displacement.