A 3 GPS-channels Doppler-delay receiver for remote sensing applications

This paper describes the hardware implementation and first tests of a 3 GPS-channels Doppler-delay receiver for remote sensing applications implemented by the Technical University of Catalonia (UPC) for the Institute of Space Studies of Catalonia (IEEC/CSIC). It can be configured for several applications. For altimetry applications: by looking at the differential delay between the correlation peaks ("waveforms") between the pseudo random noise (PRN) sequence from a visible GPS-satellite and the direct and reflected signals collected by one antenna with a broad beam pointing to the zenith, and another one pointing to the sea surface (not necessarily at nadir). For sea state determination: from the shape of the ambiguity function (both in the Doppler and delay). Additionally, the instrument can be configured for GPS occultation experiments, etc. This paper presents the description of the instrument implementation and two preliminary tests performed at the Garraf coast (South of Barcelona city, Spain) and at the Zeeland Bridge (The Netherlands).