Mars Express Bistatic Radar Experiment Operations Plan and Report 4 July 2009 Summary ======= DSN Antenna: 14 Pass: 2226 Orbit: 7062 Orbit Start Time: 2009-07-04T15:32:06 HGA Pointing: Specular Start Center End -------- ---------- -------- Specular Condition (ERT): 18:18 18:55 19:25 Target Latitude (deg N): 49.10 33.69 -54.25 Longitude (deg E): 220.17 265.72 268.29 Rp (km): 3394. 3394. 3394. Incidence/Reflection Angle (deg): 61.91 60.11 58.51 Slant Range (km): 5856. 1989. 1039. Slew Angle (deg): 56.19 59.77 62.99 Doppler (carrier, fd; Hz): 26746. 29028. -16770. Doppler (echo, fr; Hz): 42909. 53055. -38557. Doppler Difference (fdd; Hz): -16163. -24027. 21787. Earth-Mars Distance (m): 2.811E+11 2.811E+11 2.811E+11 Experiment Set Up ================= This experiment was conducted using Goldstone's DSS 14. Danny Kahan and Gene Goltz were in the Radio Science Support Area (RSSA) at JPL. Dick Simpson was available by phone. Performance Problems and Notes ============================== A communications problem resulted in having to use a satellite link between JPL and Goldstone for the first part of the pass. Normal land-line communications were restored shortly before start of the bistatic activity. Although there was no real-time evidence of problems in supporting the experiment -- except for the slow communication between station operators and the RSSG -- the quick look processing shows that the X-RCP and S-RCP noise diodes were probably left on until steps 8 and 15 of the pre-cal, respectively. Data Acquisition ================ RSRs were configured as in Table 1. Table 1 ---------------------------------------------------- RSR Channel Mode ATT FGAIN Operator dB ----- ------- ---- ---- ----- ---------------------- RSR1A S-LCP 1-W auto 60 UNK RSR1B X-LCP 1-W auto 60 UNK RSR2A S-RCP 1-W auto 60 UNK RSR2B X-RCP 1-W auto 60 UNK RSR subchannels (SCHAN) were defined as follows: Table 2 ---------------------------------------------------------------------- Subchannel Sample Rate Comments ---------- ----------- --------------------------------------------- 1 2 ksps Occultation bandwidth (not recorded for BSR) 2 8 ksps Occultation backup (not recorded for BSR) 3 25 ksps Primary recording bandwidth 4 100 ksps Backup recording Table 3 lists ADC amplitude levels read from RSR displays during the experiment. Times are in UTC and should be considered approximate. "Steps" are as defined in the briefing message. RSR ATT settings are in units proportional to dB. Acronyms and abbreviations are explained after Table 3. Table 3 ----------------------------------------------------------------------------- Activity Time Step # S-LCP X-LCP S-RCP X-RCP Notes / Comments 2009/185 RSR1A RSR1B RSR2A RSR2B -------- ----- --------- ----- ----- ----- ----- ------------------------ Set-up 15:07 60 60 60 60 Set FGAIN (dB) Pre-Cal 15:48 1 -2.2 -9.6 -12.0 -10.9 15:50 att auto -9.9 -9.6 -10.1 -9.9 ADC amplitude (dB) 16.5 12.0 4.0 11.5 Attenuator settings 15:52 2 -9.9 +0.0 -10.1 +0.1 15:54 3 -6.0 -0.1 -10.1 +0.0 15:55 4 -5.1 -0.1 -0.7 +0.0 15:56 att auto -10.0 -10.0 -10.2 -9.7 21.5 24.5 15.0 24.0 Attenuator settings Ambient load phys temps S1=19.44 S2=23.44 X1=17.38 DSS 14 weather: T=27.5C H=17.9 percent sky=clear 15:58 5 -10.0 -9.9 -10.1 -9.7 16:00 rec 3 e Begin 25 kHz recording 16:05 6 -10.1 -10.1 -9.9 -9.4 16:10 7 -10.0 -22.2 -10.0 -19.9 16:15 8 -10.2 -22.3 -10.0 -22.3 16:20 9 -10.2 -19.8 -10.0 -22.3 Confirm 12.5 noise diode 16:25 10 -10.2 -9.8 -10.0 -9.7 Ambient load phys temps: S1=19.75 S2=23.75 X1=17.88 16:30 11 -10.0 -9.9 -10.0 -9.8 16:35 12 -10.2 -22.1 -10.0 -22.4 16:40 13 -10.1 -22.2 -9.9 -22.4 16:45 14 -10.2 -22.2 -19.3 -22.4 16:50 15 -10.1 -22.3 -21.1 -22.3 confirm 12.5 noise diode 16:55 16 -9.9 -22.2 -21.2 -22.4 17:00 17 -14.5 -22.1 -21.1 -22.4 17:05 18 -16.1 -22.2 -21.2 -22.3 Ambient load phys temps: S1=20.25 S2=24.44 X1=18.19 17:10 end -14.9 -22.3 -21.3 -22.3 End 25 kHz recording BOT 17:20 -13.9 -22.2 -21.3 -22.0 Collecting telemtery until 17:48 17:40 Normal communications link restored 17:53 rtec 3 e -14.8 -22.2 -21.3 -21.9 Resume 25 kHz recording 18:00 sfro 3/SX +11K +10K +11K +10K Receiver offset (Hz) Switch to Mars pointing predicts MiniCal1 18:03 1 -15.9 -22.1 -21.3 -19.6 Confirm 12.5 noise diode 18:06 2 -16.0 -22.1 -19.8 -22.3 18:09 3 -14.7 -19.8 -21.4 -22.2 18:12 4 -12.8 -22.0 -21.3 -22.2 18:15 5 -15.0 -22.2 -21.3 -22.3 18:18 end -14.0 -22.2 -21.3 -22.2 BSR 18:18 sfro 3/SX -2K +14K -2K +14K Receiver offset (Hz) Begin 100 kHz recording 19:06 sfro 3/X +7K +7K Receiver offset (Hz) 19:10 sfro 3/X 0 0 Receiver offset (Hz) Enter Valles Marineris 19:12 -18.1 -22.0 -21.4 -21.2 Exit Valles Marineris 19:13 sfro 3/X -7K -7K Receiver offset (Hz) 19:15 sfro 3/S -9K -9K Receiver offset (Hz) 19:16 sfro 3/X -14K -14K Receiver offset (Hz) 19:19 sfro 3/X -21K -21K Receiver offset (Hz) 19:22 sfro 3/X -28K -28K Receiver offset (Hz) 19:25 sfro 3/SX +11K +10K +11K +10K End 100 kHz recording MiniCal2 19:25 1 -18.7 -22.1 -21.4 -19.2 Confirm 12.5 noise diode 19:28 2 -17.5 -21.9 -19.8 -21.2 19:31 3 -18.6 -19.9 -21.5 -21.1 19:34 4 -16.5 -21.9 -21.4 -21.2 19:37 5 -17.2 -21.9 -21.3 -21.1 19:40 end -18.2 -21.8 -21.4 -21.8 Switch to spacecraft pointing predicts EOT 19:50 -17.7 -21.9 -21.4 -21.7 Move to stow PostCal 19:55 1 -10.1 -10.1 -10.6 -9.9 Ambient load phys temps: S1=22.56 S2=28.69 X1=20.06 19:58 2 -10.0 -10.2 -10.6 -9.7 20:01 3 -10.0 -10.0 -10.5 -9.8 20:04 Repeated step 3 20:07 4 -10.0 -9.9 -10.6 -9.8 20:10 5 -9.9 -10.1 -10.7 -9.8 20:13 6 -15.3 -22.2 -21.5 -22.4 20:16 7 -16.3 -19.9 -21.6 -22.3 20:19 8 -16.5 -22.2 -19.9 -22.5 20:22 9 -16.3 -22.3 -21.6 -20.0 20:25 10 -16.0 -22.3 -21.4 -2.3 Ambient load phys temps: S1=22.69 S2=28.81 X1=20.38 DSS 14 weather: T=33.1C H=7.9 percent sky=clear EOA 20:30 end -16.7 -22.2 -21.1 -22.4 End 25 kHz recording AMB = ambient load BOT = Beginning of Track CNR = Carrier to noise ratio CONSCAN = conical scan tracking CW = continuous wave (carrier only) EOA = End of activity EOT = End of Track FRO = frequency offset HGA = high-gain antenna LOS = loss of signal ND = noise diode No = noise power Pc = carrier power rcvr = receiver S1 = ambient load for S-RCP S2 = ambient load for S-LCP SL = S-LCP SNR = Signal to noise ratio SR = S-RCP TLM = telemetry X1 = Ambient load for both X-band channels XL = X-LCP XR = X-RCP Post Analysis Summary The table below summarizes the time division of X-Band data so as to capture the echo power as the signal drifted through the 25 kHz receiving passband. Interval Times Spectra Carrier Split Notes on Echo, FRO, etc. Bin Echo -------- ----------- ------- ------- ----- -------------------------- A 18:18-18:55 001-222 -inf Drifts slowly up B 18:55-19:01 223-258 -inf Stable, broadens C 19:01-19:06 259-288 -inf Sweeps from 19 to 13 kHz FRO_X = +7000 Hz at 19:06 D 19:06-19:10 289-312 87 289 Sweeps from 19 to 13 kHz FRO_X = 0 Hz at 19:10 E 19:10-19:13 313-330 374 313 Sweeps from 19 to 13 kHz FRO_X = -7000 Hz at 19:13 F 19:13-19:16 331-348 ~660 331 Sweeps from 19 to 13 kHz FRO_X = -14000 Hz at 19:16 G 19:16-19:19 349-366 ~948 349 Sweeps from 19 to 13 kHz FRO_X = -21000 Hz at 19:19 H 19:19-19:22 367-385 +inf 367 Sweeps from 19 to 13 kHz 385 FRO_X = -28000 Hz at 19:22 I 19:22-19:25 386-402 +inf Drifts slowly, stops at 16 kHz The MOVIE program was run for the spectra ranges shown above with the first spectrum in each range also providing the last MOVIE output in the previous run (except that spectrum 385 -- instead of 386 -- was run with both Interval H and Interval I conditions). Interval F was run with "carrier suppression" both ON and OFF. "Spectra" are 10-second averages of 244 individual power spectra, numbered 001 to 402, inclusive. "Carrier Bin" is approximate location of carrier in bin numbers (1-1024) or "-inf" or "+inf" if the carrier was off the low or high end of the spectrum. "Split Echo" is the spectrum number if a FRO caused the echo spectrum to appear at two different frequencies; in these cases a wide echo window was used to capture all of the power. For S-Band, the table below summarizes the processing (60 s average spectra). Carrier suppression was used during interval B. Interval Times Spectra Carrier Split Notes on Echo, FRO, etc. Bin Echo -------- ----------- ------- ------- ----- -------------------------- A 18:18-19:06 001-048 535 Drifts slowly up B 19:06-19:18 049-060 535,822 Drifts through carrier, FRO C 18:18-19:25 061-067 822 Drifts to a stop Dick Simpson Original: 2009-09-23 Added Post Analysis Summary: 2009-10-31