Viking VISAB Mosaicked Digital Image Models (MDIM)

MDIM – Mosaicked Digital Image Models

Instrument:Visual Imaging Subsystem Cameras A and B

DOI: 10.17189/1520376.

For more information about VISAB MDIM products, see the Data Set Catalog File.

The Visual Imaging Subsystem Cameras A and B (VISAB) Mosaicked Digital Image Models (MDIMs) are a cartographic extension of the Experiment Data Records (EDRs). They contain cartographic compilations made by processing the raw images to reduce radiometric and geometric distortions to form geodetically controlled images.

There are 7 volumes of MDIMs. Volumes 1-6 have been redelivered in a second version (2.0) that has been improved in both geodetic accuracy and photometric/cosmetic appearance. The most significant change is geodetic: the present mosaic is based on a 1999 RAN global geodetic control network of Mars. This net is tied to the inertial-space position of the Mars Pathfinder spacecraft and incorporates elevation data from the Mars Orbiter Laser Altimeter (MOLA) for most control points. Its use thus eliminates a systematic error in longitude in the previous mosaic and reduces random positional errors that in some locations exceeded 20 km to typically less than 1 km. Details about these redelivered products can be found here.

In addition, the USGS has released a version 2.1 MDIM map that increases the positional accuracy of the map even more than version 2.0, as well as making more photometric and cosmetic improvements. Those map products can be found here. The 2.1 MDIM can be chosen as an ODE Basemap for displaying Mars data products.

Each of the first six volumes contains MDIMs of the areas specified at resolutions of 1/256 deg/pixel (231 m) and at 1/64 deg/pixel (943 m). Volumes 1 and 6 also contain MDIM coverage of the entire planet at 1/16 deg/pixel (3.69 km). The six volumes also include a digitized airbrush map of the entire planet at 1/16 deg/pixel (3.69 km) and at 1/4 deg/pixel.

The 1/64 deg/pixel MDIM segments which appear in volumes 1-6 are duplicated in its entirety in volume 7.

The contents of the 7 volumes are below (with links to the volume).