Mars Express Bistatic Radar Experiment Operations Plan and Report 19 October 2005 Summary ======= DSN Antenna: 14 Pass: 0871 Orbit: 2267 Orbit Start Time: 2005-10-19T08:52:52 SCET HGA Pointing: Inertial Specular Condition: 2005-10-19T13:30:00 ERT Target: (47.41N, -151.30E) Incidence/Reflection Angle: 60.58 deg Slant Range: 6998 km Slew Angle: 59.58 deg Doppler (carrier, fd): -52976 Hz Doppler (echo, fr): -46797 Hz Doppler Difference (fdd): -6179 Hz Earth-Mars Distance: 7.0796E10 m Experiment Set Up ================= This experiment was conducted using Goldstone's DSS 14. The support team at JPL included Danny Kahan, Don Fleischman, and Dick Simpson. In the NOPE area was Greg Hewitt. Performance Problems ==================== Problems with the X-LCP noise diode calibration, which had been occurring since July, were traced to a typo in the briefing message by Larry Bracamonte in early October; there were no such problems during this experiment. Also, in contrast to recent experience at DSS 14, all channels appeared to be equally stable. No significant interfering signals were found during processing. There appear to be no weather problems. The X-RCP MiniCal #1 sky measurement before the noise diode was turned on was suspect (splatter from the carrier, which raised noise power in distant bins). So Tsys for MiniCal #1 was calculated using only the sky noise level after the noise diode was turned off. The S-RCP pre-cal "upper" noise diode measurement is simply wrong; but the cause is unknown. In X-Band MOVIE processing, the X- echoes appear at spectrum 30 and disappear around spectrum 100. During spectra 2-28, the carrier is in the signal window. The carrier leaves the window just before the echo arrives; so there is no confusion in estimating the echo power. After spectrum 98, the echo is in the upper noise window. In S-Band MOVIE processing, there is a weak (but not negligible) carrier in the echo window until about spectrum 35. Since the echo appears at about spectrum 20, there is confusion during early stages of echo development. MOVIE was run for carrier suppression both ON and OFF for both S-RCP and S-LCP. There should be no problem around the time of maximum echo strength. The S-Band surface echo disappears around spectrum 100. Data Acquisition ================ The set up period began at 09:00. DSS 14 announced that it was ready to begin the pre-calibrations about 30 minutes later. The pre-calibration was nominal. RSRs were configured as in Table 1: Table 1 --------------------------------------------- RSR Channel Mode ATT FGAIN Operator dB ----- ------- ---- ---- ----- --------------- RSR2A S-LCP 1-W auto 60 Fleischman RSR2B X-LCP 1-W auto 60 Fleischman RSR3A S-RCP 1-W auto 60 Kahan RSR3B X-RCP 1-W auto 68 Kahan RSR subchannels (SCHAN) were defined as follows: Table 2 --------------------------------------------------------------------- Subchannel Sample Rate Comments ---------- ----------- --------------------------------------------- 1 1 ksps 2 8 ksps 3 25 ksps Primary recording bandwidth 4 100 ksps Backup recording Table 3 lists ADC amplitude levels read from RSR displays during the experiment. Where available, signal-to-noise ratios, frequency offsets, and other measurements are also listed. Times are in UTC read from a wall clock and may not reflect actual times when configurations changed. "Steps" are as defined in the briefing message. Acronyms and abbreviations are explained after Table 3. Table 3 ------------------------------------------------------------------------------ TIME (ERT) RSR2A RSR2B RSR3A RSR3B COMMENTS 2005-10-19 S-LCP X-LCP S-RCP X-RCP ADC ADC ADC ADC (dB) (dB) (dB) (dB) ---------- ------ ------ ------ ------ --------------------------------------- End-to-End Configuration Check 09:30 -10.0 -10.0 -10.2 -10.1 Step 01: DSS 14 ready to proceed; 11.5 8.5 7.0 5.5 ATT settings after AUTO reset (dB) 09:32 -10.7 -0.3 -10.2 -0.2 Step 02: X-band to AMB 09:34 -1.8 -0.3 -10.3 -0.1 Step 03: S-LCP to AMB 09:35 -1.7 -0.3 -2.4 -0.1 Step 04: S-RCP to AMB Pre-Calibration 09:36 Ambient load temperatures: S1 = 17.44C S2 = 19.88C X1 = 16.75C Weather conditions: T = 9.8C H = 41.9% wind = 19.8 MPH from south sky = clear 09:37 21.0 20.5 15.0 18.0 ATT settings after AUTO reset (dB) 09:37:01 All RSR's recording SCHAN=3 (25 kHz) 09:41 -10.1 -9.9 -9.8 -10.0 Step 05: configure ND controllers 09:45 -10.0 -21.9 -10.0 -20.2 Step 06: XR ND on 09:50 -10.1 -21.9 -10.0 -20.2 Step 07: X-band to sky 09:55 -10.1 -22.1 -10.1 -22.8 Step 08: XR ND off 10:00 -10.1 -19.8 -10.0 -22.5 Step 09: XL ND on; 14 confirms 12.5 ND 10:05 -10.1 -9.8 -9.9 -10.1 Step 10: X-band to AMB Ambient load temperatures: S1 = 17.38C S2 = 19.75C X1 = 16.75C 10:10 -10.1 -10.0 -10.0 -10.1 Step 11: XL ND off 10:15 -10.1 -22.1 -10.0 -22.5 Step 12: X-band to sky 10:20 -10.1 -22.0 -9.9 -22.5 Step 13: SR N D on 10:25 -10.1 -22.3 -19.0 -22.6 Step 14: SR to sky 10:30 -10.2 -22.1 -21.4 -22.6 Step 15: SR ND off 10:35 -9.8 -22.1 -21.2 -22.6 Step 16: SL ND on 10:40 -18.5 -22.3 -21.3 -22.6 Step 17: SL to sky 10:45 -19.9 -22.0 -21.5 -22.5 Step 18: SL ND off Ambient load temperatures: S1 = 17.38C S2 = 19.75C X1 = 16.69C 10:55 Stop RSR recording (SCHAN=3) Spacecraft Calibration (BCAL #1) and Slew #1 11:47 DSS 14 reports TLM in lock 11:55 NOPE reminds 14 there is no TLM rqmt; DSS 14 confirms BSR configuration 12:07 -20.3 -21.2 -21.3 -18.2 Tracking; much TLM splatter on XR 12:08 -20.2 -21.3 -21.3 -18.2 ADC amplitude (dB) 47 70 Carrier to noise ratio (dB/Hz) -2404 -2411 Carrier offset (Hz) 12:10 DSS 14 in lock on X-band carrier 12:20:01 Start RSR recording (SCHAN=3) 12:26 -20.6 -21.2 -21.3 -18.4 S Tx on; DSS 14 in lock. 18 48 57 70 Carrier to noise ratio (dB/Hz) -1229 -2514 -1234 -2521 Carrier offset (Hz) 12:38 -20.3 -21.2 -21.2 -18.2 ADC amplitude (dB) 18 48 57 70 Carrier to noise ratio (dB/Hz) -1281 -2699 -1283 -2715 Carrier offset (Hz) 12:39 MEX MOC requests TLM from DSS 14, and DSS 14 begins feeding it. Mini-Cal #1 12:39 Begin Slew #1 12:41 56 66 Carrier to noise ratio (dB/Hz) -20.5 -21.1 -21.2 -19.4 Step 01: XR ND on 12:44 -20.3 -21.1 -18.9 -20.4 Step 02: XR ND off; SR ND on X-RCP spur at +2000 Hz, drifting left 12:48 X-RCP spur at -7500 Hz, drifting left 12:49 -20.6 -19.2 -21.2 -20.8 Step 03: SR ND off, XL ND on 12:51 -18.9 -21.2 -21.2 -20.7 Step 04: XL ND off, SL ND on 12:54 -20.3 -21.1 -21.2 -20.7 Step 05: SL ND off 12:59 End slew Bistatic Radar Activities 13:07 -20.0 -21.1 -21.2 -20.8 ADC amplitude (dB) 29 33 Carrier to noise ratio (dB/Hz) -3103 -3106 Carrier offset (Hz) 13:10 DSS 14 locked to X-RCP carrier; unable to lock to S-RDSP carrier. 13:23 First echoes on X-LCP 13:25 Echoes in all channels 13:30 -20.3 -20.9 -21.0 -21.1 X echoes same strength in RCP, LCP 23 24 Echo signal to noise (dB/Hz) 170 3000 300 3000 Echo offset (Hz) 13:37 S echoes gone 13:40 X echoes gone (last at +7500 Hz) 13:45 Stop RSR recording (SCHAN=4) 13:57 -20.0 -20.8 -21.0 -20.8 ADC amplitude (dB) Mini-Cal #2, Slew #2, and BCAL #2 14:00 -20.0 -20.7 -21.0 -18.9 Step 01: XR ND on Begin Slew #2 14:03 -20.1 -20.7 -18.8 -20.2 Step 02: XR ND off, SR ND on 14:06 -19.9 -18.7 -20.9 -20.3 Step 03: SR ND off, XL ND on 14:09 Step 04: XL ND off, SL ND on 14:12 -19.6 -20.4 -20.7 -20.3 Step 05: SL ND off 14:20 -20.0 -20.3 -20.7 -18.7 End Slew #2 19 54 56 76 Carrier to noise ratio (dB/Hz) -1430 -3238 -1428 -3237 Carrier offset (Hz) Post-Calibration 15:00 EOT; DSS 14 going to zenith 15:11 -10.2 -10.0 -10.3 -10.2 Step 01: All channels to AMB at zenith Ambient load temperatures: S1 = 16.62C S2 = 18.81C X1 = 15.69C 15:15 -10.1 -10.0 -10.2 -10.0 Step 02: XR ND on 15:17 -10.2 -10.0 -10.0 -10.1 Step 03: XR ND off, SR ND on 15:20 -10.2 -9.8 -10.2 -10.1 Step 04: SR ND off, XL ND on 15:23 -10.1 -10.0 -10.2 -10.0 Step 05: XL ND off, SL ND on 15:26 -18.1 -22.1 -21.4 -22.6 Step 06: All to sky 15:29 -20.1 -19.8 -21.4 -22.5 Step 07: SL ND off, XL ND on 15:32 -20.5 -22.1 -19.1 -22.5 Step 08: XL ND off, SR ND on 15:35 -20.0 -22.0 -19.1 -22.5 Step 09: SR ND off, XR ND on 15:38 -19.7 -22.0 -21.4 -22.6 Step 10: XR ND off Ambient load temperatures: S1 = 16.69C S2 = 18.94C X1 = 15.69C Weather conditions: T = 13.9C P = 906 mbar H = 38 per cent Sky clear; wind 3 mph from E 15:41 End of activity Stop RSR recording (SCHAN=3) AMB = ambient load BOT = Beginning of Track CONSCAN = conical scan tracking CW = continuous wave (carrier only) EOT = End of Track FRO = frequency offset HGA = high-gain antenna LOS = loss of signal ND = noise diode No = noise power Pc = carrier power S1 = ambient load for S-RCP S2 = ambient load for S-LCP SL = S-LCP SR = S-RCP TLM = telemetry X1 = Ambient load for both X-band channels XL = X-LCP XR = X-RCP Dick Simpson Original: 2005-10-19 Added orbit start time and entries starting at 15:32: 2005-10-20 spelling correction: 2006-01-01 Processing notes added: 2006-03-12 minor edits: 2006-07-02