Venera Radar, Venera-15 and -16 Missions Options

[Guest_DonPMitchell_*]

I've been fiddling with Venera radar data. These two mapping orbiters have been somewhat forgotten, after the dramatic results form Magellan, but they were very important. For six years, they were the only really good images of the surface of Venus, studied by the experts in Russia and America. Most of the major ideas about Venusian surface geomorphology comes from this data - coronae, lack of tectonic activity, the low meteorite crator count and relative youth of the surface, etc.

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The SAR data is high frequency only, because of the use of automatic gain control. But the altimetry data can be used to create a nice hill-shaded low-frequency component. The raw data is in various conformal projections, but very precisely registered. Thank god! It turned out to be easy to combine all of it into one spherical map with no seams.

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Here are the orbits of all Venus satellites (except Venus Express). The two darker orbits are Magellan (the smaller one) and Pioneer Venus (at one point in time). The two extremely eccentric orbits are Venera-9 and 10, placed in molniya orbits to "hover" over the Venera landers while relaying their data. The two Venera radar mappers are in 24 hour orbits. They made a close pass over the north pole, recording radar holograms, and then replay the results to Earth during the rest of the orbit.