The dust scale height of the Martian atmosphere around Pavonis Mons from HRSC stereo images
Abstract
The Martian atmosphere contains large and variable amounts of aerosols, mainly consisting of airborne dust. The High Resolution Stereo Camera (HRSC) onboard the European orbiter Mars Express is a powerful tool for studying the distribution of dust in Mars' atmosphere. An essential parameter for such studies is the optical depth, which can often be estimated from contrast differences between HRSC stereo images with the so called `stereo method'. Software for this purpose has been developed at the MPS in Lindau, Germany. The method uses map-projected ortho-images and complementary data on the imaging geometry from photogrammetric software developed at DLR. On September 23, 2005, during orbit 2175 of Mars Express, HRSC imaged Pavonis Mons and regions around it in stereo; these span height differences of nearly 10 km. Obviously, the amount of dust in the Martian atmosphere varies with elevation. We use the images to study how optical depth depends on altitude. Independent of altitude, the measured optical depths show important (up to about a factor of two) local variations on horizontal scales of a few tens of kilometers that may well be related to winds and obstacles like crater walls and mountains.
- Publication:
-
European Planetary Science Congress 2006
- Pub Date:
- 2006
- Bibcode:
- 2006epsc.conf..251H