Mars Express Bistatic Radar Experiment Operations Plan and Report 22 January 2006 Summary ======= DSN Antenna: 14 Pass: 966 Orbit: 2606 Orbit Start Time: 2006-01-22T06:04:44 SCET HGA Pointing: Specular Track (first attempt) Specular Condition (ERT): 06:20:00 06:50:00 07:20:00 Target Latitude (deg N): 38.64 43.35 48.33 Longitude (deg E): 95.10 91.12 88.90 Rp (km): 3383.823 Incidence/Reflection Angle (deg): 55.21 60.06 65.46 Slant Range (km): 11299 11171 10622 Slew Angle: 69.59 59.97 49.08 Doppler (carrier, fd; Hz): -30671 -27984 -23094 Doppler (echo, fr; Hz): -4804 1232 6934 Doppler Difference (fdd; Hz): -25867 -29216 -30028 Earth-Mars Distance (m): 1.448E+11 Experiment Set Up ================= This experiment was conducted using Goldstone's DSS 14. The support team at JPL included Danny Kahan, Gene Goltz, Essam Marouf, Sami Asmar, and Dick Simpson. Jesse Velasco was in the NOPE area. The MEX MOC briefing message included instructions for both uplink commanding and downlink telemetry. Goltz confirmed with the NOPE and DSS 14 that neither was required; MEX MOC concurred after some review. For the first time the spacecraft HGA was programmed to track the specular point. This meant that there were surface echoes for the full hour of BSR recording (plus a little more on either end). Performance Problems and Notes ============================== During the experiment on 2006/021, the S-RCP maser failed. Station personnel had investigated the problem but not found a solution in time for this experiment. There was no substitute LNA, so the S-RCP channel was abandoned. DR G106461 documented the data loss. For unknown reasons, the X-RCP noise diode was enabled twice during the first mini-cal; and there was no enabling of the X-LCP diode. So parts of steps 2- 4 were repeated to get the X-LCP diode signal after the first surface echoes appeared. There was occasional interference on X-RCP, presumably from MGS, throughout the pass. The X-RCP and X-LCP quasi-specular echoes appeared on schedule, drifted slightly during the hour, and disappeared on schedule. The S-LCP echo was probably there, but only detectable in a transient sense using the real-time display. There was a shift change at 08:00; the new crew had a little trouble getting up to speed given complications such as the red lines in the post-cal procedure resulting from loss of the S-RCP channel. It appears that the S-LCP ND was turned on about 08:06, before the receivers all went to AMB; this means there is AMB+ND, SKY, and SKY_ND calibration during the post-cal but no AMB. Data Acquisition ================ RSRs were configured as in Table 1: Table 1 --------------------------------------------- RSR Channel Mode ATT FGAIN Operator dB ----- ------- ---- ---- ----- --------------- RSR3A S-LCP 1-W auto 60 Kahan RSR3B X-LCP 1-W auto 60 Kahan RSR2A N/A 1-W auto 60 Goltz RSR2B X-RCP 1-W auto 68 Goltz RSR subchannels (SCHAN) were defined as follows: Table 2 ---------------------------------------------------------------------- Subchannel Sample Rate Comments ---------- ----------- --------------------------------------------- 1 1 ksps backup (not recorded) 2 8 ksps backup (not recorded) 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 ----------------------------------------------------------------------------- Step/ RSR3A RSR3B RSR2A RSR2B Time Action S-LCP X-LCP N/A X-RCP Ancillary Information ----- -------- ----- ----- ----- ----- ---------------------------------- FRO 0 0 0 0 RSR frequency offset (Hz) ********************************** PRE-CAL ********************************** 03:50 01 -10.1 -10.1 -26.7 -10.1 Velasco says DSS 14 is ready 18.5 11.0 0.0 10.5 RSR ATT after AUTO reset 03:57 -13.3 -10.1 -42.8 -10.2 Goltz changes S-RCP ATT setting 03:58 02 -11.5 -0.2 -45.2 -0.0 X-Band to sky 04:00 03 -16.9 -0.2 -43.8 0.0 SL to sky 04:02 -10.1 -10.0 -- -10.0 ADC amplitude (dB) 21.5 23.0 23.0 Reset ATT using AUTO Ambient load physical temperatures S1 = 16.44C S2 = 19.06C X1 = 13.25C DSS 14 weather: T = 48F H = 47 percent P = 904 mb W = 0 mph sky = clear 04:07 05 -10.0 -9.9 -- -9.9 Start 25 kHz recording (SCHAN=3) 04:10 05 -10.0 -10.0 -- -9.7 XR ND ON 04:15 07 -10.0 -20.9 -- -20.1 X-Band to sky 04:20 08 -10.1 -22.2 -- -22.7 XR ND OFF 04:25 09 -10.0 -19.8 -- -22.8 XL ND OFF; DSS 14 conf ND=12.5 Ambient load physical temperatures S1 = 16.19C S2 = 18.69C X1 = 13.05C 04:30 10 -10.0 -9.9 -- -10.0 X-Band to AMB 04:35 11 -10.0 -9.9 -- -10.0 XL ND OFF 04:40 12 -10.0 -22.1 -- -22.6 X-Band to sky 04:42 13 Reconfigure DTT01 for X-RCP 04:46 15 -10.0 -22.6 -- -22.6 Reconfigure DTT02 for S-LCP DSS 14 confirms ND=12.5 04:47 16 -9.9 -22.1 -- -22.6 SL ND ON 04:50 17 -17.8 -22.2 -- -22.6 SL to sky 04:55 18 -19.2 -22.2 -- SL ND OFF Ambient load physical temperatures S1 = 15.94C S2 = 18.44C X1 = 13.00C 05:05 -18.0 -22.2 -- -22.6 Stop 25 kHz recordings *************************** BOT, BCAL #1, SLEW #1 *************************** 05:06 DSS 14 going to point 05:16 -21.9 -- -20.9 DSS 14 on point 05:21 -18.8 -21.9 -- -21.0 DSS 14 X-RCP in lock 05:22 X+S 1-way, TLM OFF 47.5 -- 73.0 Carrier-to-noise (dB/Hz) -2452 -- -2471 Carrier offset (Hz) 05:35 Start 25 kHz recording (SCHAN=3) 05:50 47.4 -- 73.4 CNR (dB/Hz) -2852 -- -2868 Carrier offset (Hz) 06:05 -18.5 -21.7 -- -20.9 ADC amplitude (dB) 15.7 47.2 -- 73.3 CNR (dB/Hz) -1800 -3018 -- -3041 Carrier offset (Hz) 06:06 Begin Slew #1 06:08 FRO +3000 +25000 -- +25000 Center echo in passband (Hz) ********************************_MINI-CAL #1 ******************************** 06:09 01 -20.4 -21.6 -- -19.7 XR ND ON 06:12 02 -20.7 -21.6 -- -21.9 XR ND OFF 06:15 03 -20.4 -21.5 -- -19.3 XR ND ON (wrong diode) Echoes on all 3 channels 06:18 04 -18.8 -21.6 -- -21.5 XR ND OFF; SL ND ON 06:21 05 -20.7 -21.7 -- -21.5 SL ND OFF Start 100 kHz recordings (SCHAN=4) 06:24 02 Repeat lines 3-7 (DTT01 to X-LCP) 06:25 03 -20.6 -19.5 -- -21.5 Repeat line 2 (XL ND ON) 06:28 04 -20.4 -21.3 -- -21.6 Repeat lines 1,3-7 (XL ND OFF) ************************************ BSR ************************************ 06:28 32 -- 26 Echo SNR (dB/Hz) -900 -- -1000 Echo offset (Hz) 1500 Echo bandwidth (Hz) 06:51 -20.5 -21.3 -- -21.4 ADC amplitude (dB) 34 33 Echo SNR (dB/Hz) 1220 1051 Echo offset (Hz) 1000 1000 Echo bandwidth (Hz) 07:00 XR interfering signal drifting -50 Hz/sec, merges with surface echo 07:10 Another interfering signal, 40 kHz 07:17 End 100 kHz recordings *********************** MINICAL #2, SLEW #2, BCAL #2 ************************ 07:17 01 -20.3 -21.1 -- -19.3 XR ND ON 07:20 02 -20.3 -21.2 -- -21.2 XR ND OFF Begin Slew #2 back to Earth point End surface echoes 07:23 03 -20.2 -19.2 -- -21.1 XL ND ON 07:26 04 -18.6 -21.2 -- -21.0 XL ND OFF; SL ND ON 07:29 05 -20.4 -21.1 -- -21.1 SL ND OFF 07:32 19.2 46.0 -- 72.2 CNR (dB/Hz) -7000 -28200 -- -28200 Carrier offset (Hz) End Slew #2 07:35 FRO 0 0 -- 0 Return carrier to center (Hz) 13.0 46.3 -- 72.3 CNR (dB/Hz) -1419 -3206 -3208 Carrier offset (Hz) ********************************* POST-CAL ********************************* 07:50 EOT 07:55 Going to zenith 08:11 01 -9.7 -9.9 -- -9.8 All to AMB Ambient load physical temperatures S1 = 13.70C S2 = 16.12C X1 = 13.00C 08:17 02 -9.8 -9.9 -- -9.6 XR ND ON 08:20 03 -9.8 -10.0 -- -9.9 XR ND OFF 08:23 04 -9.7 -9.8 -- -9.9 XL ND ON; config DTT02 for S-LCP 08:26 05 -9.7 -10.0 -- -9.9 XL ND OFF; SL ND ON (no change) 08:29 -9.5 -10.0 -- -9.9 Late XL ND ON? 08:30 06 -18.8 -22.2 -- -22.4 All to sky 08:32 07 -18.9 -19.8 -- -22.5 SL ND OFF(?); XL ND ON 08:34 -19.4 -19.8 -- -22.5 Late SL ND OFF? 08:36 08 -20.3 -22.0 -- -22.5 XL ND OFF 08:38 09 -20.4 -22.2 -- -20.1 XR ND ON 08:41 10 -20.6 -22.1 -- -22.6 XR ND OFF 08:42 05 -18.5 SL ND ON (Step 5, line 2) 08:43 07 -20.4 SL ND OFF (Step 7, line 1) 08:45 Stop 25 kHz recordings Ambient load physical temperatures S1 = 13.3C S2 = 15.8C X1 = 12.7C Weather at DSS 14: T = 32F H = 36 percent P = 904 mb W = 4 MPH from W sky = partly cloudy End of activity AMB = ambient load BOT = Beginning of Track CNR = Carrier to noise ratio CONSCAN = conical scan tracking CW = continuous wave (carrier only) EOT = End of Track FRO = frequency offset HGA = high-gain antenna LNA = low noise amplifier 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 SNR = Signal to noise ratio SR = S-RCP TLM = telemetry X1 = Ambient load for both X-band channels XL = X-LCP XR = X-RCP Dick Simpson Original: 2006-01-22 Added orbit start time to summary and LNA to acronym list: 2006-07-04