Venus mapper resolution

Abstract

NASA program managers for the Venus Radar Mapper (VRM) mission have decided to make improvements to the spacecraft's Synthetic Aperture Radar (SAR) system that will increase its mapping resolution by one and a half times over the original design. The changes, including a doubling of the system's range bandwidth, will add a total of about $5 million to a project budgeted at $350 million. VRM is scheduled for launch toward Venus in April 1988 and will map more than 90% of the cloud‐veiled planet's surface during its 8‐month mission.The decision by the VRM program office at NASA headquarters in Washington was based on recommendations from the mission's project office at the Jet Propulsion Laboratory in Pasadena, Calif. When VRM was included as a new start in this year's NASA budget, the stated goals for the mission were to provide a near‐global map of Venus at resolutions better than 1 km, or roughly equivalent to the resolution of the Mariner 9 mission that first revealed the geological richness of the Martian surface. The actual best radar resolution was to have been about 180 m (equivalent to an optical line‐pair resolution of 360 m) attainable for more than half the surface of the planet. VRM will travel an elliptical orbit and so will only be able to map the surface for a fraction of each day. The highest resolutions will come in the equatorial regions when the spacecraft is closest to periapsis and the radar “look angles” are the greatest.