Comparison of remote sensing observations of planetary wind streaks

Abstract

Wind streaks are common aeolian features observed on terrestrial planets. They were first identified on Mars; thus, the associated terminology is based on Mars-related observations usually describing surface patterns with distinct albedos. However, terms related to reflected tones are only relevant to past knowledge for Mars, and not necessarily suitable for description of radar-visible streaks located on Venus, Titan, or Earth. Furthermore, the sensor type used to observe wind streaks can influence the subsequent data analysis. The purpose of this study was to examine the effects of sensor type on wind streak identification and interpretation. Six case studies featuring wind streaks on Earth were performed, using imaging by both radar and optical sensors. The results indicate that wind streak identification is constrained to a specific combination of sensor settings appropriate for the local surface properties. Only half the optically visible wind streaks considered in this study were also radar-visible, but all the wind streaks observable in the radar images also appeared in the optical images. Furthermore, “bright” and “dark” (reflectance and backscatter) are relative terms and should be used with caution. These results suggest that the Venusian wind streak database is most likely far from complete and that many more streaks exist.