Quantification of Errors in the Planetary Atmospheric Profiles Derived From Radio Occultation Measurements

Abstract

Abstract Radio occultation (RO) measurement is an established technique for profiling planetary atmosphere/ionosphere. The accuracy of the derived physical parameters (atmospheric temperature, pressure, and density in the lower atmosphere, and electron density in the ionosphere) however depends on uncertainty in the observed frequency and robustness of the retrieval algorithm. The objective of this paper is to identify all possible sources of errors in RO experiments and their propagation to the retrieved atmospheric profiles. Quantification of errors due to assumptions used in the retrieval algorithm has also been attempted. We used the data from one‐way downlink single‐frequency (X‐band) radio signals, transmitted from the radio science payload onboard Akatsuki spacecraft orbiting Venus and received at Indian Deep Space Network, Bengaluru, India for this study. We followed the standard signal processing technique to analyze the raw data. Atmospheric profiles were retrieved using the basic concept of geometrical optics. Possible sources of errors in RO experiments are identified and their magnitude range has been quantified. The propagation of errors in obtained atmospheric profiles is also discussed. These results would be useful while devising RO experiments for future planetary explorations.