The PARIS Multi-Band receiver is a GNSS reflection receiver capable of operating at L-band and other higher (C/X/K) bands. Its signal processor implements the so-called interferometric technique Martín Neira et al. 2011 (PARIS-IT), that consists of cross-correlating the direct and reflected signals received by the up-looking and down-looking antennas, respectively. This instrument has been designed and manufactured at the Institut of Space Sciences (CSIC/IEEC) Ribó 2013.
Figure 1 shows a block diagram of the instrument. It consists of a 19inch rack of 3U height (labelled PARIS-MB S/P), with external additional hardware. This 19inch rack is a dual channel L-band receiver, capable of receiving and down-converting radio signals in a sub-band of 4-40 MHz base-band bandwidth, between 1-2 GHz. Gain and bandwidth of both downconversion chains are programmable. The instrument can operate at a higher band by using external Low Noise Blocks (LNB's) [An LNB is a low noise amplifier followed by a down-conversion stage to intermediate frequency] that shift the signals from X-band, or any other desired band to a frequency between 1 GHz and 2 GHz. The receiver does also provides 10 MHz coherent reference clocks to feed the LNBs, so that the down-conversion from a high frequency band is coherent with the system's local oscillator and clocks. Any desired antenna (horn feed, horn feed with dish reflectors, ...) can be connected at the input of the LNBs.
The receiver samples each in-phase and quadrature component of both base-band down-converted signals at 80 Msamples/second and quantizes them using 10 bits per sample. Only the three most significant bits are used in further signal processing.
The digital signal processor computes the complex cross-correlation between both signals in a 200 lags window. Lag separation corresponds to one sampling period, that is, 1/80 MHz = 12.5 ns. The origin of the correlation window is selectable (from 0 lags to 255 lags) by programming individually an additional delay to each signal. A new cross-correlation is computed every millisecond. An embedded GPS receiver delivers GPS time information to the system and the obtained cross-correlation waveforms are time-tagged accordingly. Finally, the data is saved in real-time to an external (laptop) computer through an ethernet connection.
The system's power supply is a 19 inch rack of 2U height, and it is supplied with 220V AC. The power supply is labelled PARIS-MB P/S. Figure 2 shows a picture of the the system.
Figure 1: Block diagram of the PARIS-MB receiver.
Figure 2: Picture of the PARIS-MB receiver.
Data CitationPlease cite some of the papers below in public use of PARIS-MB data sets (about PARIS-MB data):
DATA PUBLICATION/CITATION:Serni Ribó, Juan Carlos Arco, Santi Oliveras, Estel Cardellach, Antonio Rius, Christopher Buck, Experimental Results of an X-Band PARIS Receiver Using Digital Satellite TV Opportunity Signals Scattered on the Sea Surface, TGRS,10.1109/TGRS.2013.2292007
Cardellach, E., Fabra, F., Nogu&ecaute;-Correig, O., Oliveras, S., Ribó, S., Rius, A., GNSS-R ground-based and airborne campaigns for Ocean, Land, Ice and Snow techniques: application to the GOLD-RTR datasets, Radio Science, 46, RS0C04, 2011, oct, doi: 10.1029/2011RS004683
ABOUT THE PARIS-MB RECEIVER:Serni Ribó, Juan Carlos Arco, Santi Oliveras, Estel Cardellach, Antonio Rius, Christopher Buck, Experimental Results of an X-Band PARIS Receiver Using Digital Satellite TV Opportunity Signals Scattered on the Sea Surface, TGRS, 10.1109/TGRS.2013.2292007