GNSS Reflectometry (GNSS-R)
GNSS Reflectometry (GNSS-R) involves making measurements of the reflections from the Earth using navigation signals from the Global Navigation Satellite Systems (GNSS). The technique is similar to that used by both existing altimeter and scatterometer radar satellites, but eliminates the need for dedicated transmitters, through the use of existing GNSS signals as a bistatic radar.
The reflections contain an imprint of the physical state of the surface and have found application in monitoring:
- Oceanography (Wave roughness and wind speed)
- Soil moisture and flooding
- Cryosphere (Ice extent, type, and elevation)
The GNSS-R instrument developed by Spire is particularly novel due to its form factor, processing 4 GNSS constellations, to deliver up to 32 simultaneous reflection measurements. With almost 11 years of flight heritage, the payload offers more observations with all the benefits of a CubeSat form factor.
- Lowe Stephen T. Space-Based Positioning; Navigation; and Timing National Advisory Board. Earth Remote Sensing using Surface-Reflected GNSS Signals (GNSS-Reflectometry). 15 Nov 2017. Accessed 23 October 2018.
- Zribi M.; Motte E.; Baghdadi N.; Baup F.; Dayau S.; Fanise P.; Guyon D.; Huc M.; Wigneron J.P. Potential Applications of GNSS-R Observations over Agricultural Areas: Results from the GLORI Airborne Campaign. Remote Sens. 2018; 10; 1245. Accessed 23 October 2018.
- Mistrale Project | GNSS Reflectometry. Accessed 22 Oct 2018.