First Dual-Band Multiconstellation GNSS-R Scatterometry Experiment Over Boreal Forests From a Stratospheric Balloon

This work presents the first ever dual-frequency multiconstellation Reflectometry using Global Navigation Satellite Systems signals (GNSS-R) observations over boreal forests and lakes using GPS, GLONASS, and Galileo signals. The instrument used is the PYCARO reflectometer, which flew on-board a stratospheric balloon during the SNSB and ESA sponsored BEXUS 19 experiment. The coherent-to-incoherent scattering ratio over boreal forests is found to be as large as similar to 1.5, while over lakes, it is as high as 16.5. The scatterers' height fluctuations measured using the phase of the peak of the reflected complex waveforms ranges from similar to 10 m, to the submetric level. Finally, reflectivity maps using the different GNSS codes are presented using the conventional GNSS-R for the open-access codes, and the reconstructed GNSS-R for the encrypted ones. The coherence of the reflected signal is found to be high enough to allow the PYCARO instrument to reconstruct the P(Y) code.