Pioneer Venus Orbiter Radar Mapper: Design And Operation

The Radar Mapper Experiment, carried abroad the Pioneer Venus Orbiter spacecraft, is designed to obtain a near-global picture of the topography, meter-scale surface slopes and reflectivity of Venus. Constraints imposed by the choice of orbit limit radar coverage to a latitude band lying between 74°N and 61°S completely around the planet. In addition to the altimetry objectives, the experiment seeks an image of the radar scattering properties of the surface at oblique incidence. Sensitivity limits the imaged region to a band around the planet lying between 45°N and 10°S. Altimetric error is less than 200 m; altimetric surface "footprint" size varies from about 10 km in diameter at a spacecraft altitude of 200 km, to 50 km at a maximum altitude of 4700 km. Imaging resolution varies from 20 to 40 km, depending on spacecraft altitude.