Ionospheric corrections on L-band SAR offset tracking image for precise observation of glacier velocity

Ionospheric streaks occur frequently in polar region by ionospheric path delays on radar signals, particularly with L-band SAR systems, because L-band SAR data is much more sensitive to ionospheric effects along the SAR swath path. So we correct the ionospheric streaks on the SAR offset tracking maps using directional filter along the range direction. Through this technique, the standard deviation in stable area for the azimuth offset maps are reduced up to 2.82 m146 days that is from 3.01 to 0.19 m146 days, and the accuracy improved about 94%. We can precisely observe the glacier velocity using the suggested method.