GNSS Reflectometry (GNSS-R) for Environmental Monitoring

Abstract

ABSTRACT Global Navigation Satellite System Reflectometry (GNSS-R) is emerging as a promising remote sensing technique for environmental monitoring. It utilizes the reflected signals from GNSS satellites, such as GPS, GLONASS, Galileo, and BeiDou, to infer the properties of Earth's surface and atmosphere. Unlike traditional remote sensing systems that require active transmitters or complex sensors, GNSS-R leverages existing satellite signals, making it cost effective and scalable. In this review paper, we summarize the principles, methods, applications, challenges, and future prospects of GNSS-R in environmental monitoring. We give emphasis on its use in soil moisture estimation, sea level and wave height measurement, snow and ice monitoring, vegetation sensing, and atmospheric profiling. We also discuss limitations and propose recommendations for further research. This overview offers insights to researchers and practitioners interested in deploying GNSS-R approaches for environmental observation.

KEYWORDS: GNSS Reflectometry, Remote Sensing, Soil Moisture, Sea Level Monitoring, Atmospheric Sensing, Biophysical Parameters, Signal Reflectance.