E-SAR, “Experimental-SAR”, is an airborne imaging radar (Synthetic Aperture Radar) sensor formerly operated by the German Aerospace Center (DLR), Microwaves and Radar Institute (HR) from 1988 until November 2009.
It is operated on a Dornier Do-228 aircraft in 3000 to 6000 m above ground in five different center frequencies (X,C,L,P1,P2), wavelengths of 3 cm, 5 cm, 23 cm and 85 cm, two of them in P-band. Different center frequencies are operated sequentially (not simultaneously) in overflights. Data are acquired either in one-channel, two-channel or four-channel mode in HH, HV, VV and/or VH polarization. Fully polarimetric data are acquired in L- and P-band only.
Repeat-pass interferometry is available in L- and P-band. Single-pass interferometry is available in X-band (ATI and/or XTI) only.
Data are processed up to two different levels: RGI (Radar Geometry Image product) and GTC (Geocoded and Terrain-Corrected product).
Resolutions range from 25 cm (X-band) to 1.5 m (P-band) in azimuth direction and from 1.8 m (X-band) to 3 m (P-band) in range direction.
Data acquisition modes are typically “stripmap”, “repeat-pass” (two parallel tracks) or “tomography” (several parallel tracks) or can be individually planned experiments.
A brief description of E-SAR data formats can be downloaded here.