Image Processing and image description
For the Mars 2020 Perseverance Rover landing site at Jezero crater special PR release, a variety of data form the Mars Express (MEx) and Mars Reconnaissance Orbiter (MRO) were utilised. The HRSC HMC30 products produced by the Global Topography and Mosaic Generation Task Group (GTMTG) of the HRSC Science Team serve as a reference dataset all other datasets were registered to. The original HMC30 product tiles can be downloaded here and browsed in an interactive map environment here. A number of higher resolution image data from the Context Camera (CTX) on board MRO were incorporated in the basemap. In total, 33 CTX swaths having an average resolution of 6 m/px were orthorectified and co-registered to the HRSC data by bundle adjustment, using the USGS Integrated Software for Imagers and Spectrometers (ISIS). After this geometric alignment, the CTX images were radiometrically normalised using the HRSC grayscale mosaic as a brightness reference. The colour information was transferred from the 50 m/px HRSC mosaic to the highly resolved CTX data by pan-sharpening. The existing HiRISE image mosaic of an even higher resolution of 0.5 m/px, created by the USGS Astrogeology Science Center in the course of the Terrain Relative Navigation (TRN) project for the rover, has already been aligned very well to the HRSC base dataset. HRSC colour has also been applied to the otherwise grayscale HiRISE dataset using pan-sharpening. The DTM basemap was combined from the HMC30 mosaic tile and the existing HiRISE DTM mosaic from the TRN project as available here.