Shapefiles of mapped units in Ganesh and Gilmore "Microwave Emissivity Variations Across Ovda Regio, Venus" published in Journal of Geophysical Research, Planets

Many highlands on Venus emit anomalously low amounts of microwave energy at high elevations. Such low microwave emission is consistent with the presence of rocks with either highly conductive compounds or non-conducting crystals capable of spontaneous polarization as a function of temperature. The presence of these compounds provide insights into past atmospheric and surface processes on Venus. We look at the microwave signature of Ovda Regio, which contains structurally complex tessera terrain and an unusual volcano. The data show a ∼2x spread in the magnitude of minimum microwave emission, and a diffuse transition from high to low emissivity spread over ∼1.5 km of surface elevation. To understand the source of this spread in the microwave observations, we investigate how surface emission relates to morphology and structures across Ovda tessera. The observed spread in the microwave data is best explained by non-uniformity in age, rock type, composition, and weathering of the surface. This non-uniformity within tesserae might not just be limited to Ovda Regio and might represent variable geologic age and surface characteristics for all tesserae.