Community tools for cartographic and photogrammetric processing of Mars Express HRSC images

• Published in: Planetary Remote Sensing and Mapping pp. 107 - 124
• Main Authors: Kirk, R. L., Howington-Kraus, E., Edmundson, K., Redding, B., Galuszka, D., Hare, T., Gwinner, K.
• Format: Book Chapter
• Language: English
• Published: CRC Press 2019
• Edition: 1
• Subjects: BAE System; Nadir Image; High Resolution DEM; Pixel Scale; Sinusoidal Projection; Instrument Team; Sensor Model; Automated Image Matching; RFM; Pushbroom Scanner; Point Cloud Alignment; Boxcar Filter; PDS; HiRISE; RMS Deviation; Ground Control Points; MSL; Exposure Time; Pushbroom Images; Multi-image Matching; Altimetry Data; Automatic Terrain Extraction; Photometric Modeling; Planetary Community; HRSC
• ISBN: 9781138584150; 1138584150
• DOI: 10.1201/9780429505997-9

In this chapter we describe the software we have developed for photogrammetric processing of images from the Mars Express High Resolution Stereo Camera (MEX HRSC) to produce digital topographic models (DTMs) and orthoimages, as well as testing we have performed. HRSC has returned images, including stereo and color coverage of most of Mars at decameter scales. The instrument team has developed an extremely powerful processing pipeline and delivered a large number of high-level data products, but our independent software is nevertheless of interest because it provides a check on the standard products, sheds light on the capabilities of software elements we use for multiple missions besides HRSC, and is publicly available, giving users the opportunity to make products that may not (yet) be released by the team and custom products such as local mosaics. We have tested our software on images of three areas: Candor Chasma and Nanedi Valles (both the subject of past DTM comparisons reported by Heipke et al., 2007) and Gale crater, which was extensively mapped at pixel scales 50 times finer than HRSC before its selection as the landing site of the Curiosity rover. We find the vertical precision and mean deviation from the altimetry data used as a control reference for our DTMs to be comparable to the nadir image pixel size. The horizontal resolution of the DTMs appears to be an order of magnitude coarser than the lower limit of 3–5 image pixels that is commonly stated. The High Resolution Stereo Camera (HRSC) on the Mars Express orbiter is a multi-line pushbroom scanner that can obtain stereo and color coverage of targets in a single overpass. The initial implementation of this capability utilized the then-current Integrated Software for Imagers and Spectrometers (ISIS) system and the generic pushbroom sensor model of SOCET SET, and was described in the Digital Terrain Model comparison of independent photogrammetric processing by different elements of the HRSC team. The software described is, for the most part, already available to the planetary community. The HRSC sensor model and translation programs will be included in an upcoming (ISIS) release. In addition to implementing the needed sensor models and other software, we have developed and documented procedures for processing single-orbit and multi-orbit datasets. The low contrast strategy is effective for planetary mapping because it compensates for major brightness variations across the images, allowing local textural features to be detected more readily.