GNSS-R

Using GNSS-R (for English. Global Navigation Satellite System and Reflectometry or Passive Reflectometry and Interferometry System short PARIS ) can be the nature of reflective surfaces (eg., Water, soil, snow) determined by applying the multipath reception of the signal of a navigation satellite is evaluated.

If a GPS satellite is on the horizon, the receiver sees both the direct signal and the time-delayed signal, which is reflected on the surface of the water in the grazing incidence. Since the position of the satellite is known with high accuracy, the delay in travel time results in a phase shift of the coherent satellite signal as a function of the relative water height. The speckles of the signal allow conclusions to be drawn about the roughness and movements of the water surface.

Aircraft or satellite-borne receivers extend the reception angle of GNSS satellites.

Web links

• Space Technologies for the Benefit of Human Society and Earth , by Phillip Olla