Evaluating GeoOptics Radio Occultation Data for Ionospheric Research
- Camella Nasr
- Nov 13
- 2 min read
Camella Nasr, Ionospheric Scientist
Image furnished by NASA
The monitoring and understanding of Earth’s ionosphere—a critical region for communication, navigation systems and space weather—rely on innovative data sources and methods. NASA's Commercial Smallsat Data Acquisition (CSDA) program was created to tap into the growing commercial satellite industry. Orion Space Solutions serves as one of NASA's expert evaluators, helping determine if commercially available satellite data meets NASA's high standards for scientific research.
As part of our role on the program, we have been working with GeoOptics, a new vendor to the CSDA program, to assess the applicability of their radio occultation (RO) data for measuring total electron content (TEC) and supporting ionospheric research.
Our evaluation focused on data gathered between January 2020 and May 2021, with the objective of determining its suitability for NASA’s ionospheric research goals and broader applications. Our findings provide insight into how well GeoOptics TEC measurements complement existing datasets and advance ionospheric studies.
ASSESSING ACCURACY AND COVERAGE
GeoOptics is contributing data collected by three high-inclination satellites. One of the key evaluation metrics is the accuracy of GeoOptics TEC measurements. We compared their data to that from COSMIC-2/FORMOSAT-7, a reliable benchmark in ionospheric TEC studies. By selecting overlapping orbital regions—equatorward of 24 degrees and at local times of approximately 10 and 22—our team quantified the absolute accuracy of GeoOptics "overhead" TEC (elevation angles greater than 60 degrees). Aggregated daily measurements from both datasets were compared statistically to determine alignment and accuracy.
For further evaluation, we used another benchmark: ionosondes. Through an Abel inversion, GeoOptics TEC data was used to create electron density profiles (EDPs), which we then compared to auto scaled EDPs from ionosonde stations collocated with the satellite paths. This step added another layer of validation to assess the overall quality of the GeoOptics dataset.
Coverage was the second critical factor we analyzed. Using the full dataset, we examined the range of elevation angles and altitudes covered by each occultation. To dig deeper, a "day-in-the-life" analysis mapped how often the GNSS-to-LEO satellite raypaths intersect the ionosphere at different latitudes, local times, and altitudes. From this analysis, we visualized the average revisit rates for GeoOptics and compared them to the existing datasets from COSMIC-2 and Spire, two vendors already part of the CSDA program.
THE VALUE OF GEOOPTICS FOR IONOSPHERIC RESEARCH
Our evaluation highlighted the potential role GeoOptics TEC data can play in advancing ionospheric research. Specifically, GeoOptics contributes valuable insights that enhances NASA’s existing datasets to help refine ionospheric specification and modeling.
The inclusion of GeoOptics as part of NASA’s CSDA program illustrates the expanding potential of commercial satellite data for scientific research. As more small satellites enter orbit, so does the opportunity to enhance our understanding of Earth’s atmosphere and its critical regions, like the ionosphere.
Orion Space Solutions is proud to be part of this important evaluation. To see a poster presentation of this work as it was originally presented, click the link below.
ABOUT THE AUTHOR
Dr. Camella Nasr studies planetary atmospheres at Orion Space Solutions, where she focuses on understanding ionospheric dynamics. Her background includes extensive research on the atmosphere of Mars, analyzing winds, jet streaks, and planetary waves. She specializes in identifying large-scale atmospheric patterns and the influence of magnetic fields on climate behavior.
