Software Defined Radio system for GNSS-Refectometry: activities performed at the Politecnico of Turin (Italy)

• Main Authors: CUCCA, MANUELA, NOTARPIETRO, RICCARDO, PINI, MARCO, FALCO, GIANLUCA, Panicciari T., Patti S., DOVIS, Fabio
• Other Authors: Cucca, Manuela, Notarpietro, Riccardo, Panicciari, T., Patti, S., Dovis, Fabio, Pini, Marco, Falco, Gianluca
• Format: Conference Object
• Language: English
• Published: 2011
• Subjects: Arctic; Antarctic; Antarc*; Sea ice
• Online Access: http://hdl.handle.net/11583/2500883; http://202.127.29.4/GNSS/program.html

The GNSS signals are an important active source for Earth’s remote sensing in L band. Experiments performed over sea and land surfaces demonstrated the capability of GNSS-Reflected signals (GNSS-R) for remote sensing purposes. Presently, many research groups are focusing their efforts in developing GNSS-R sensors for soil moisture, sea, sea-ice, and snow cover monitoring. Applications like drought monitoring, farm production, irrigation planning, flood protection, fire prevention, and meteorological forecasts can take advantage from retrieved soil moisture content. Detected sea-surface winds could help to identify adverse meteorological conditions far from coastal zones. Sea altimetry measurements could be used to monitor tides and to identify natural hazards (i.e. tsunamis). Sea-ice topographic changes in the Arctic and Antarctic regions and dry ice stratification could be monitored in order to improve polar climatology knowledge. Recently the Remote Sensing Group of Politecnico of Turin and NavSAS laboratory of ISMB (Istituto Superiore Mario Boella) starts the design and implementation of a fully reconfigurable GNSS-R instrument for research activities, following a Software Defined Radio approach. Using this solution, the hardware is reduced to the RF stages only (i.e. antennas, demodulation, sampling) and the processing starts from the IF (Intermediate Frequency) samples of the raw signal. This is a low-cost portable observing system, designed to be easily placed for example also on board small aircrafts (also unmanned). In this sense, the system components were carefully chosen to minimize size and weight of the complete observing system. Together with the system definition, a user interface is started to be developed. Actually the interface allows a quasi real time control of the received signal. The correct estimation of the whole correlation function profile (in range and frequency space) is achieved by keeping the noise level as low as possible and increasing the SNR. Therefore, it is important to ...