PARIS-MB User Manual - ice
Contents
1. 132. phase_up_2 Quadratic phase component d2 applied to the up signal during the current second see equation 9 delay_dw_0 Constant group delay component d applied to the down signal during the current second see equation 8 delay_dw_1 Linear group delay component d applied to the down signal during the current second see equation 8 delay_dw_2 Quadratic group delay component d gt applied to the down signal during the current second see equation 8 phase_dw_0 Constant phase component 9 applied to the down signal during the current second see equation 9 phase_dw_1 Linear phase component d applied to the down signal during the current second see equation 9 phase_dw_2 Quadratic phase component d gt applied to the down signal during the current second see equation 9 12 References 1 M Martin Neira S D Addio C Buck N Floury and R Prieto Cerdeira The PARIS Ocean Altimeter In Orbit Demonstrator Geoscience and Remote Sensing IEEE Transactions on 49 6 2209 2237 June 2011 2 MAX2112 Complete Direct conversion Tuner for DVBS2 Applications Technical report Maxim 2010 3 Serni Ribo Juan Carlos Arco Santi Oliveras Antonio Rius and Christo pher Buck Experimental results of an X band PARIS receiver using digital satellite TV opportunity signals scattered on the sea surface Sub mitted to Geoscience and Remote Sensing IEEE Transactions on 2013
3. input of the LNB s 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 An LNB is a low noise amplifier followed by a down conversion stage to intermediate frequency The digital signal processor computes the complex cross correlation be tween 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 ev ery 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 GPS antenna Dish Coaxial Feedhorn cable LNB one 10 MHz Coaxial cab Feedhorn Figure 1 Block diagram of the PARIS MB receiver 2 Interfaces Figure 2 shows a picture with all external interfaces at the front panels of the receiver and
4. the in phase component of the up signal I_UP_A2 This is the filter coefficient a for q 2 in 7 for the in phase component of the up signal I_UP_A3 This is the filter coefficient a for q 3 in 7 for the in phase component of the up signal I_UP_BO This is the filter coefficient bp for p 0 in 7 for the in phase component of the up signal I_UP_B1 This is the filter coefficient bp for p 1 in 7 for the in phase component of the up signal I_UP_B2 This is the filter coefficient bp for p 2 in 7 for the in phase component of the up signal I_UP_B3 This is the filter coefficient bp for p 3 in 7 for the in phase component of the up signal Q_UP_AO This is the filter coefficient a for q 0 in 7 for the quadra ture component of the up signal Q_UP_A1 This is the filter coefficient a for q 1 in 7 for the quadra ture component of the up signal Q_UP_A2 This is the filter coefficient a for q 2 in 7 for the quadra ture component of the up signal Q_UP_AS3 This is the filter coefficient b for q 3 in 7 for the quadrature component of the up signal Q_UP_BO This is the filter coefficient b for p 0 in 7 for the quadrature component of the up signal Q_UP_B1 This is the filter coefficient bp for p 1 in 7 for the quadrature component of the up signal Q_UP_B2 This is the filter coefficient b for p 2 in 7 for the quadrature component of the u
5. PARIS MB User Manual Serni Rib Institut de Ci ncies de l Espai CSIC IEEC January 7th 2014 Version 1 0 1 Instrument Description The PARIS Multi Band receiver is a GNSS reflection receiver capable of op erating at L band and other higher C X K bands Its signal processor im plements the so called interferometric technique 1 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 3 Figure 1 shows a block diagram of the instrument It consists of a 19 inch rack of 3U height labelled PARIS MB S P with external additional hardware This 19 inch 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 down conversion chains are programmable The instrument can operate at a higher band by using external Low Noise Blocks LNB s 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 LNB s 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
6. amming the MAX2112 mixing stage 2 The local oscillator frequency Fro is obtained from the mixer frequency Fmrx Frer by using the formula Fro MFrer 4 where M is a rational multiplier N is the integer part of M F The local oscillator frequency is obtained by programming the MAX2112 mixing stage 2 The local oscillator frequency Fo is obtained from the mixer frequency Fmrx Frer by using 4 F is the fractional part of M BW The bandwidth of the down conversion chain can selected by pro gramming the MAX2112 mixing stage This field holds the value of register 9 LPF of the MAX2112 down converter 2 The actual 3dB bandwidth is obtained by using the formula f sap 4 MHz BW 12 0 290 MHz 5 BBG_up The gain of the MAX2112 mixing stage can be adjusted at baseband by programming its control register bits BBG 2 This field holds the baseband gain for the up channel expressed in dB from OdB to 15dB in 1dB steps BBG_up The gain of the MAX2112 mixing stage can be adjusted at baseband by programming its control register bits BBG 2 This field holds the baseband gain for the down channel expressed in dB from OdB to 15dB in 1dB steps VAS The MAX2112 down conversion stage includes 24 VCOs The lo cal oscillator frequency can be manually selected and by setting the VAS bit to logic 1 the MAX2112 selects automatically the appropriate VCO 2 freq Most recent estimation of the reference clo
7. ck frequency Nominal frequency is Frer 80MHz Frequency count is given in counts per minute minus 2 So a reading of 505 032 893 corresponds to a refer ence frequency of Frer LT 80 000 003 15 MHz LNB fact A 10MHz frequency is delivered to the LNB blocks to generate the local oscillator frequency of the LNB Fy yg This LNB local oscil lator frequency is obtained by multiplying the 10MHz frequency by a multiplication factor Fine LN Bfact10 MHz 6 GRF_coarse_up The gain of the MAX2112 down converter can be ad justed at RF by setting a control voltage 2 This is accomplished by using two digitally programmable potentiometers one for coarse ad justment of the voltage and a second one for fine adjustment This variable holds the programming value for the coarse adjustment of the up chain GRE _fine_up The gain of the MAX2112 down converter can be adjusted at RF by setting a control voltage 2 This is accomplished by using two digitally programmable potentiometers one for coarse adjustment of the voltage and a second one for fine adjustment This variable holds the programming value for the fine adjustment of the up chain GRF_coarse_dw The gain of the MAX2112 down converter can be ad justed at RF by setting a control voltage 2 This is accomplished by using two digitally programmable potentiometers one for coarse ad justment of the voltage and a second one for fine adjustment This variable holds the prog
8. l Q DW BO This is the filter coefficient b for p 0 in 7 for the quadra ture component of the down signal Q_DW_B1 This is the filter coefficient b for p 1 in 7 for the quadra ture component of the down signal Q DW B2 This is the filter coefficient b for p 2 in 7 for the quadra ture component of the down signal Q_DW_B3 This is the filter coefficient b for p 3 in 7 for the quadra ture component of the down signal delay_offset The up signal can be delay by an integer amount of clock cycles lags This value indicates the magnitude of the delay delay_up_0 Constant group delay component d applied to the up signal during the current second see equation 8 The signal processor 11 applies a dynamic group delay to the input signals which is modelled by a polynomial T do d t dot 8 delay_up_1 Linear group delay component d applied to the up signal during the current second see equation 8 delay_up_2 Quadratic group delay component dz applied to the up signal during the current second see equation 8 phase_up_0 Constant phase component o applied to the up signal dur ing the current second see equation 9 The signal processor applies a dynamic phase model to the input signals which is modelled by a polynomial b po dit dot 9 phase_up_1 Linear phase component d applied to the up signal during the current second see equation 9
9. nent of the down signal for the current millisecond The real cross correlation at lag m R m is measured using this formula 1 N gt ol 3 0 where N 79 796 is the number of signal samples integrated in 1 ms The three MSB bits of the input signals are used to compute the prod uct and the accumulation register is 23 bits broad 22 bits plus one sign bit The 16 MSB of this register are read out so k 64 3 2 STSMB nc File Format The NetCDF data format for the status files consists of an array of entries where each entry corresponds to the status of the instrument for a given second The contents of each field is described below x is the x coordinate of the receiver position expressed in the ECEF GPS frame register up x n m 3 aa a 22 multiplier g 3 i down y n adder g gt 16 PMS readout orn Aa cara hate eee ttt Figure 5 Block diagram of one single correlator lag y is the y coordinate of the receiver position expressed in the ECEF GPS frame z is the z coordinate of the receiver position expressed in the ECEF GPS frame week is the GPS week at which the measurement has been taken sow is the GPS second of week at which the measurement has been taken pv isa boolean that indicates if the time week sow and position x y z are valid N The local oscillator frequency is obtained by progr
10. p signal Q_UP_B3 This is the filter coefficient bp for p 3 in 7 for the quadrature component of the up signal I_DW _AO This is the filter coefficient a for q 0 in 7 for the in phase component of the down signal I_DW _A1 This is the filter coefficient a for q 1 in 7 for the in phase component of the down signal IDW_A2 This is the filter coefficient a for q 2 in 7 for the in phase component of the down signal 10 I DW_A3 This is the filter coefficient a for q 3 in 7 for the in phase component of the down signal I_DW_BO This is the filter coefficient bp for p 0 in 7 for the in phase component of the down signal I_DW_B1 This is the filter coefficient bp for p 1 in 7 for the in phase component of the down signal I_DW_B2 This is the filter coefficient bp for p 2 in 7 for the in phase component of the down signal I_DW_B3 This is the filter coefficient b for p 3 in 7 for the in phase component of the down signal Q_DW_AO This is the filter coefficient a for q 0 in 7 for the quadra ture component of the down signal Q_DW _A1 This is the filter coefficient a for q 1 in 7 for the quadra ture component of the down signal Q_DW_A2 This is the filter coefficient a for q 2 in 7 for the quadra ture component of the down signal Q_DW_A3 This is the filter coefficient b for q 3 in 7 for the quadra ture component of the down signa
11. power supply Their names and functions are shown in table 1 Figure 2 Picture of the PARIS MB receiver 3 Data Format The data collected by the PARIS MB receiver is saved in two types of NetCDF files WAVMB nc Contains waveforms and calibration data for a complete minute Data rate within the file is 1 ms STSMB nc Contains instrument status information for a complete minute Data rate within the file is 1 s 3 1 WAVMB nc File Format The NetCDF data format for the waveform files consists of an array of entries where each entry corresponds to a time tagged complex waveform 1 ms real time integrated with its corresponding simultaneous Offset and PMS measurements The contents of each field is described below week is the GPS week at which the measurement has been taken sow is the GPS second of week at which the measurement has been taken Table 1 External interfaces offset_iup offset_qup Connector Function Type Receiver J1 RF1 up supply LNB TNC female J2 10MHz reference RF1 TNC female J3 10MHz reference RF 2 TNC female J4 RF2 down supply LNB TNC female J5 GPS for external GPS antenna TNC female J6 Keyboard PS 2 J7 Screen VGA DE 15 J8 Ethernet 1 192 168 63 62 CTRL RJ 45 J9 Ethernet 2 192 168 63 61 RJ 45 J10 Power Supply Input Circular multi pin male Power Supply J1 220V Circular three pins J2 Supply to Recei
12. ramming value for the coarse adjustment of the dw chain GRE _fine_up The gain of the MAX2112 down converter can be adjusted at RF by setting a control voltage 2 This is accomplished by using two digitally programmable potentiometers one for coarse adjustment of the voltage and a second one for fine adjustment This variable holds the programming value for the fine adjustment of the dw chain RUN This boolean variable indicates if the correlator was running LSB The correlation data is accumulated in a 23 bits register but only 16 bits are read out This variable shows the LSB bit that is being read out from the accumulator TEST Indicates whether an external signal is used 0 or an internal test signal 1 SRC_UP Meaningful only when TEST 0 If SRC_UP 1 the signal input into connector J1 up is used otherwise the signal input into connector J4 down SRC_DW Meaningful only when TEST 0 If SRC_DW 1 the signal input into connector J1 up is used otherwise the signal input into connector J4 down I_UP_AO This is the filter coefficient a for q 0 in 7 for the in phase component of the up signal All signal components are digitally filtered digitally FIR IIR before being cross correlated The filter function is Q gt mel q 2an p 7 where x n is the input signal and z n the output signal I_UP_A1 This is the filter coefficient a for q 1 in 7 for
13. ured using the same formula as for offset_iup pms_iup is the total power measurement of the in phase component of the up signal for the current millisecond The total power P for signal x n is measured by using this formula 1 N Pap yon 2 where N 79 796 is the number of signal samples integrated in 1 ms It must be taken into account that the signal s n is quantized using ten bits per sample but just the three MSB are used to compute the power value After N consecutive accumulations in a 22 bits register the 16 MSB of this register are the read out value The value k 64 takes this into account pms_qup is the total power measurement of the quadrature component of the up signal for the current millisecond It is measured in the same way as pms_iup register 3 23 22 22 x n multiplier _ gs 3 i a adder s 16 PMS readout T2 orn pt eee eMac 3 Figure 4 Block diagram of the PMS measurement circuit pms_idw is the total power measurement of the in phase component of the down signal for the current millisecond It is measured in the same way aS pms_iup pms_qup is the total power measurement of the quadrature component of the down signal for the current millisecond It is measured in the same way as pms_iup ii is the real cross correlation term between the in phase component of the up signal and the in phase compo
14. ver Circular multi pin female F Fuse 3 15A millisecond is the millisecond within the current sow at which the mea surement has been taken is the DC value measurement of the in phase component of the up signal for the current millisecond The DC signal offset value O for signal x n is measured using this formula 1 N a Dein 1 o 0 where N 79 796 is the number of signal samples integrated in 1 ms The signal s n is quantized using ten bits per sample but just the three MSB are used to compute the DC offset After N consecutive accu mulations in a 22 bits register 16 bits are read out from this register These are bits 17 down to 2 The value k 4 takes this into account is the DC value measurement of the quadrature component of the up signal for the current millisecond The DC signal offset value O for signal x n is measured using the same formula as for offset _iup register 23 3 22 X n a adder l 17 16 Offset readout 2 2 1 0 Figure 3 Block diagram of the signal DC offset measurement circuit offset_qdw is the DC value measurement of the in phase component of the down signal for the current millisecond The DC signal offset value O for signal x n is measured using the same formula as for offset_iup offset_qdw is the DC value measurement of the in phase component of the down signal for the current millisecond The DC signal offset value O for signal x n is meas
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