Reflectometry With an Open-Source Software GNSS Receiver: Use Case With Carrier Phase Altimetry

A novel approach using open-source GNSS software demonstrates centimeter-level precision in carrier phase altimetry by extending coherent integration time (CIT) beyond the standard 20-ms limit. This method, tested at the Cordouan Lighthouse and during a high-altitude flight over a lake, enables robust measurements of amplitude ratio and differential carrier phase between direct and reflected signals. The findings highlight the potential for precise altimetry applications, including ocean surface wind and wave height retrieval, as well as environmental monitoring such as soil roughness and snow/ice characteristics. By leveraging signal processing techniques like bit sign wiping, this research advances GNSS reflectometry as a versatile tool for remote sensing.

Lestarquit, L., Peyrezabes, M., Darrozes, J., Motte, E., Roussel, N., Wautelet, G., Frappart, F., Ramillien, G., Biancale, R., & Zribi, M. (2016). Reflectometry With an Open-Source Software GNSS Receiver: Use Case With Carrier Phase Altimetry. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 9(10), 4843–4853. https://doi.org/10.1109/jstars.2016.2568742