On remote sounding of the upper atmosphere of Venus

Some of the possibilities for remote sensing of the upper atmosphere of Venus from an orbiting spacecraft are studied quantitatively. Temperature sounding over a wide vertical range, from the main cloud top near 60 km altitude to the nanobar level near 160 km, is shown to be feasible. Techniques which deconvolve the cloud structure from the temperature profile measurements are examined. Humidity measurements by simple radiometry are feasible for column abundances greater than or equal to 10 precipitable micrometers. The information content of limb radiance measurements, in different wavelengths and for various viewing geometries, is also analyzed.