Radio Occultation Web Page Development

Abstract

Global Navigation Satellite System Radio Occultation (GNSS-RO) is an important remote sensing technique for weather forecasting, climate monitoring, and ionospheric research. Within this data ecosystem, the NOAA STAR GNSS-RO webpage serves a critical role as the primary provider of up-to-date GNSS-RO data for, but not limited to, the NOAA National Centers for Environmental Prediction (NCEP) Weather Prediction Center, the Joint Center for Satellite Data Assimilation (JCSDA), and the European Centre for Medium-Range Weather Forecasts (ECMWF). The work detailed in this paper thus focuses on reinforcing the continued reliability of the site while also expanding it with new functionality to better serve users. These changes include better routing and a new multi-graph view for the Integrated Calibration/Validation System (ICVS) pages, a new monthly mean humidity anomaly (MMHA) page, tooling to analyze downloaded product statistics, and the implementation of the Ground Tracker application. The primary focus of the paper, the Ground Tracker application, is a web-based tool for plotting and interacting with large quantities of GNSS-RO profiles. Users are able to visualize the position of the profiles on a 2D (equirectangular) and 3D (globe) projection, view profile metadata (such as time, quality, LEO altitude, etc.), and compare profiles based upon GNSS ID, mission name, penetration depth, SNR value, and quality. Profile data is automatically populated from the PlanetiQ, COSMIC-2, and Spire missions and the GPS, GLONASS, GALILEO, and BEIDOU GNSS systems from July 2025 onwards. This work ensures that the Radio Occultation webpage remains a useful and important component of the GNSS-RO data ecosystem.