PDS_VERSION_ID = PDS3 PRODUCT_ID = "BROWINFO.TXT" RECORD_TYPE = STREAM RELEASE_ID = 0001 REVISION_ID = 0000 OBJECT = TEXT PUBLICATION_DATE = 2016-10-01 NOTE = "Description of the BROWSE directory contents for the MARSIS Reduced Data Record - Subsurface Archive Volume." END_OBJECT = TEXT END The BROWSE directory contains Portable Network Graphics (PNG) files of the content of MARSIS RDR data products, i.e. radargrams survey plots of the data which constitute the primary archive products of this volume. Browse images are organized into the same subdirectory structure used for data products, and each image file represent a sequence of all radargrams contained in the corresponding data product. MARSIS is capable of acquiring echoes at one or two frequencies simultaneously, and in one or more directions, depending on instrument mode. The most commonly used mode, SS3, acquires data at two frequencies, and, for each frequency, on-board processing focuses echoes towards three different directions, namely nadir, one footprint forward and one footprint backwards (see description of each instrument mode in the EAICD for details). This means that a single SS3 data product contains three radargrams for each frequency, for a total of six radargrams. Browse images for SS3 thus consist of six radargrams, stacked vertically.