Preliminary Assessment of CICERO Radio Occultation Performance by Comparing with COSMIC I Data

Abstract

Community Initiative for Cellular Earth Remote Observation (CICERO) is a planned constellation of low-earth-orbiting 6U cubeSats for performing GNSS radio occultation (RO) of Earth’s atmosphere and surface. The goal of CICERO is to provide the first and high-quality commercial radio occultation data from space at low costs while enhancing weather and climate forecasting capabilities. Before CICERO data are used for reliable weather forecasting, the assessment of its performance is necessary. This study shows the performance of CICERO by comparing it with that of COSMIC I. The performance analysis was carried out with respect to geographic distribution, altitude distribution, and refractivity error. The results show that CICERO can acquire global coverage of data at low altitudes as well as COSMIC I, which is important for climate research. In addition, the analysis of refractivity error and its impact on temperature demonstrates that the miniature version of the GNSS RO receiver could satisfy certain accuracy requirements of the GNSS RO measurements. Thus, the cubeSat constellation CICERO can provide radio occultation measurements comparable to those of the COSMIC I mission. The study demonstrates the capabilities of nanosat-based LEO cubeSats to improve data obtainability and accuracy for weather forecasting.