Radar images of Venus were obtained using the Arecibo radar system in August, 1999, and again in March/April, 2001. The 2001 observations included the first scheduled use of the new Robert C. Byrd 100-meter Green Bank Telescope. The Arecibo Observatory and the GBT together serve as a radar interferometer with the objective of creating high resolution topographic maps of Maxwell Montes at spatial resolutions adequate to determine the relationship between areas of high reflectivity/low emissivity and altitude. This work has been carried out by D. Campbell (Cornell/NAIC), J.-L. Margot (Caltech), L. Carter (Cornell), B. Campbell (NASM) and J. Dorris (Cornell). Other objectives include looking for surface features which had changed since the Magellan mission, and to obtain images in the four Stokes parameters to look at the polarization properties of the surface. Of particular interest are the floors and ejecta deposits of impact craters and the high reflectivity/low emissivity surfaces found at high elevations. Linear polarization of 10 to 40 percent is found in several areas of the maps. Areas with high linear polarization seem to be associated with radar-bright regions near impact craters.ˆà

The delay-Doppler images below were obtained by transmitting continuously from Arecibo Observatory and receiving the radar echoes at the 100 meter Green Bank Telescope. This SC image (same sense circular polarization as that transmitted) of the front part of Venus has been spatially averaged to approximately 5 km resolution.ˆà

This SC image shows a portion of Maxwell Montes, spatially averaged to 1.2 km resolution.ˆà