Gordon H. Pettengill

TL;DR: The Mars Orbiter Laser Altimeter (MOLA) has been used to measure the topography, surface roughness, and 1.064-μm reflectivity of Mars and the heights of volatile and dust clouds as mentioned in this paper.

TL;DR: Elevations measured by the Mars Orbiter Laser Altimeter have yielded a high-accuracy global map of the topography of Mars, which includes the low northern hemisphere, the Tharsis province, and the Hellas impact basin.

TL;DR: An unimodal distribution of relief for Venus was obtained from the Pioneer Venus altimetry measurements as discussed by the authors, showing that the "upland" rolling plains constituting 65% of the surface show dark circular lava-filled impact basins; highlands in the 8% area comprise Ishtar Terra and Aphrodite Terra; and the lowlands consist of crudely circular surfaces with low relief within the highlands.

TL;DR: In this paper, the Magellan radar altimeter has made some three million measurements of the surface of Venus covering the latitude range from 85 deg N to 80 deg S. Methods involving range correlation, Doppler filtering, multiburst summation, and range migration are used to focus the observations and to achieve high surface resolution.

TL;DR: In this paper, a topographic map of 93% of the Venus globe was depicted by the radar altimeter of the Pioneer Venus orbiter with a resolution better than 150 km, and the distribution of average meter-scale surface slopes was determined for the same regions in the 1 to 10 deg range.