SAR Observation of Ionosphere Using Range/Azimuth Sub-bands

While in conventional SAR applications the ionosphere is usually considered as a disturbance that has to be removed or compensated, in this paper the ionosphere is the objective of the investigation. This is motivated by the fact that nowadays polarimetric SAR systems can provide high resolution ionospheric maps that are not possible using conventional ionospheric mapping instruments. This paper investigates a set of ionospheric parameters that can be observed and mapped by exploring range and azimuth sub-bands in SAR imagery. The range sub-bands are used to estimate the ionosphere independently of polarimetry. The azimuth sub-bands are related to the threedimensional geometry of the ionosphere, as well as to its dynamic component. The potential to estimate these parameters from SAR sub-bands is discussed and first results using ALOS PALSAR data are presented.