Radar altimetry of large Martian craters
Abstract
Mars topography in the 23 to -22° latitude band has been measured by the Goldstone λ13-cm radar during the 1971-1982 oppositions. A total of 108 scans were produced. Each scan spans several tens of degrees in longitude. The longest scan spans 133° (∼8000 The vertical resolution generally is better than 200 m. With some exceptions, the areal resolution is 0.16° (∼8 km) in longitude and 1.30° (∼80 km) in latitude. On regional scales, elevation differences of as much as 3 km over less than 10° longitude have been observed (Aeolis, Memnonia). Most local relief is provided by structural elements of impact craters. One hundred fifty-two complex, degraded craters, some as small as 25 km in diameter, have been identified in this data set. Repeated scans of the same craters yield nearly identical elevation profiles. Measured crater depths rarely exceed 2.5 km. Depths of the most degraded craters in the sample are a weak function of crater diameter. Depths of the largest craters D>125km show no functional relationship to diameters. Measured rim heights rarely exceed several hundred meters. Structures with no discernible rim (e.g., Ladon) have retained a basin shape. Low exterior relief rather than overall low relief seems to be the distinguishing characteristic of large, degraded craters included in the Goldstone sample. Craters or basins that serve as sinks for major channel systems (e.g., Gusev, Ladon) appear to be as deep as comparable structures not associated with such systems, suggesting that processes other than fluvial sedimentation contributed to crater shallowing.
- Publication:
-
Icarus
- Pub Date:
- June 1989
- DOI:
- 10.1016/0019-1035(89)90079-1
- Bibcode:
- 1989Icar...79..289R
- Keywords:
-
- Altimetry;
- Mars Craters;
- Radar Data;
- Radio Altimeters;
- Mars Surface;
- Relief Maps;
- Topography;
- MARS;
- CRATERS;
- RADAR METHODS;
- ALTIMETRY;
- TOPOGRAPHY;
- ELEVATION;
- DEPTH;
- SIZE;
- TERRAIN;
- DIAGRAMS;
- PHOTOGRAPHS;
- MORPHOLOGY;
- DATA;
- DIAMETER;
- EARTH-BASED OBSERVATIONS