Mars Express Bistatic Radar Experiment Operations Plan and Report 02-03 April 2005 Summary ======= DSN Antenna: 43 Pass: 672 Orbit: 1555 Orbit Start Time: 2005-04-03T00:52:18 (SCET) HGA Pointing: Inertial Specular Condition: 2005-04-03T03:04:00 (ERT) Target: (50.58S, 70.14W, 3386 km) (southern highlands) Incidence/Reflection Angle: 51.11 deg Slant Range: 7426 km Slew Angle: 77.67 deg Doppler (carrier, fd): -23808 Hz Doppler (echo, fr): 22806 Hz Doppler Difference (fdd): -44614 Hz Earth-Mars Distance: 2.37078E11 m Data Acquisition ================ The experiment was supported by DSS 43 staff at the Canberra DSN complex. The support team at JPL included Gene Goltz, Danny Kahan, John Klose, and Dick Simpson. In the NOPE area were Jose Valencia and Jesse Velasco. The experiment began with pre-calibration activities starting on 02 April at 22:30; the pre-cal was completed more than an hour ahead of schedule. The bistatic surface observations were collected in the interval 02:30-03:30, but echoes were seen during only about 20 minutes centered in that interval. The post-calibration was completed and the RSR's stopped recording at 04:50 on 03 April. Valencia had improved the calibration procedure and briefing message compared with the version which had been used in the previous experiment on 25-26 February. There were only two minor problems, which he planned to address in future briefing messages. At one point in the pre-calibration, there were two configuration changes rather than the customary one. In the post- calibration, there was an Operator Directive to set the noise diode frequency explicitly to ON; this conflicted with the default value of 20 used by the station. RSRs were configured as follows. Table 1 -------------------------------------- RSR Channel Mode ATT FGAIN Operator dB ----- ------- ---- ---- ----- -------- RSR1A S-LCP 1-W auto 60 Kahan RSR1B X-LCP 1-W auto 60 Kahan RSR2A S-RCP 1-W auto 60 Goltz RSR2B X-RCP 1-W auto 60 Goltz Subchannels were defined as follows: Table 2 --------------------------------------------------------------------- Subchannel Sample Rate Comments ---------- ----------- --------------------------------------------- 1 1 ksps Used for seeking weak carrier signals 2 8 ksps 3 25 ksps Primary recording bandwidth 4 100 ksps Backup recording (able to capture both X-band residual carrier and surface echo) Predicts were provided by NSS and were for one-way operation. Table 3 lists ADC RMS levels read from RSR displays during the experiment. Times in hh:mm are in UTC from the RSSG wall clock, which was reset prior to the experiments. During the 26-27 February experiment, the wall clock appeared to be about 2 minutes fast. For more accurate times, see the next section of this report on Amplitude Calibration. Acronyms/abbreviations are explained below Table 3; "steps" are explained in more detail in the accompanying "procedures" document. Table 3 ----------------------------------------------------------------------------- TIME (ERT) RSR1A RSR1B RSR2A RSR2B COMMENTS 2005-04-02 S-LCP X-LCP S-RCP X-RCP RMS RMS RMS RMS ---------- ----- ----- ----- ----- ----------------------------------------- 22:30 Voice net established (MEX MOC, MEX NOPE, DSS 43, and RSSG) 22:53 28 28 28 28 DSS 43 reported it was configured per Item 7b of the Briefing Message (BM) 22:56 DSS 43 confirmed BM Item 7d Step-1 22:59 28 88 28 89 X-band to ambient load (AMB) 23:01 84 88 28 89 S-LCP to AMB 23:03 84 88 86 89 S-RCP to AMB 23:04 Reset all RSR attenuators using AUTO 23:05 28 30 29 28 Begin recording, all RSR's (SCHAN=3) 23:09 28 30 29 28 DSS 43 reports AMB physical temperatures: S1=21.00, S2=22.19, X1=21.06 23:10 29 30 DSS 43 confirms ND set to 12.5K 23:15 28 7 29 11 X-band to sky (RCP ND still on) 23:20 28 7 29 7 X-RCP ND OFF 23:26 28 10 29 7 X-LCP ND ON 23:30 28 31 29 28 X-band to AMB 23:31 DSS 43 reports AMB physical temperatures: S1=21.12, S2=22.06, X1=20.88 23:34 DSS 43 current weather conditions: Humidity 32% Temperature 23C Sky light cloud cover 23:35 28 7 29 7 X-band to sky; X-LCP ND OFF 23:43 28 7 30 7 S-RCP ND ON 23:46 27 7 9 7 S-RCP to sky (ND still ON) 23:51 28 7 7 7 S-RCP ND OFF 23:54 DSS 43 reports they have reset the ND to 12.5K; it apparently defaulted to 0.25, but we may not have seen it in the RSR because it was disabled 23:57 29 7 7 7 S-LCP ND ON 00:02 9 7 7 7 S-LCP to sky 00:07 7 7 7 7 S-LCP ND OFF 00:12 Stop all RSR recordings ----------------------------------------------------------------------------- TIME (ERT) RSR1A RSR1B RSR2A RSR2B COMMENTS 2005-04-03 S-LCP X-LCP S-RCP X-RCP RMS RMS RMS RMS ---------- ----- ----- ----- ----- ----------------------------------------- 01:20 Carrier visible; SNR=45 dB at -8800 Hz S-RCP RSR 25 kHz bandwidth and SNR=44 dB at -30 kHz in 100 kHz X-RCP window. 01:25 Weak carriers visible in S-LCP and X-LCP 01:30 8 7 8 7 All RSRs begin recording subchannel 3; X-LCP SNR=29 dB at -35 kHz, S-RCP SNR=44 at -9.5 kHz 01:36 8 7 8 7 S-RCP SNR=46 at -1253 Hz, X-RCP SNR=69 at -2600 Hz (TLM OFF) 02:00 8 7 8 7 Insert FRO on all channels. S-LCP SNR=21 at -6327 Hz, X-LCP SNR=32 at -46 kHz, S-RCP SNR=46 at -6332 Hz, X-RCP SNR=61 at -45387 Hz 02:13 Slew in progress; S-LCP SNR=0, X-LCP SNR=0, S-RCP SNR=42, X-RCP SNR=23 02:14 7 DSS 43 reports LOS 02:15 8 8 8 7 02:16 8 8 8 12 X-RCP ND ON 02:19 8 8 9 7 X-RCP ND OFF; S-RCP ND ON 02:22 DSS 43 reports they disconnected the wrong receiver (for controlling noise diode); they will go back to do it again 02:24 8 11 8 7 X-LCP ND ON; S-RCP ND OFF 02:28 9 8 8 8 S-LCP ND ON; X-LCP ND OFF 02:30 Begin recording all RSRs (SCHAN=4) 02:31 8 8 8 12 X-RCP ND ON (accident) 02:33 8 8 8 8 X-RCP ND OFF 02:58 Hints of X-LCP echo near -2000 Hz 03:00 X-LCP echo moved to near 0 Hz 03:03 X-LCP echo SNR=25 dB peaking at 1315 Hz; intermittent X-RCP echo near 1500 Hz 03:05 X-LCP echo SNR=27 at 2107 Hz; X-RCP echo peak at 1714 Hz 03:08 X-LCP echo peaks at 3222 Hz, weaker 03:10 Echoes gone 03:30 Stop RSR recordings (SCHAN=4) 03:35 9 9 9 9 03:36 9 9 9 12 X-RCP ND ON 03:39 9 9 10 9 S-RCP ND ON; X-RCP ND OFF 03:42 9 12 9 9 X-LCP ND ON; S-RCP ND OFF 03:45 10 9 9 9 S-LCP ND ON; X-LCP ND OFF 03:48 9 9 9 9 S-LCP ND OFF 03:50 All FRO set to 0 03:58 DSS 43 going to zenith 04:01 8 8 8 8 04:05 27 29 29 28 All channels to AMB; DSS 43 reports S1=21.56, S2=22.44, X1=18.69 04:10 27 29 29 30 X-RCP ND ON 04:13 28 29 29 28 X-RCP ND OFF 04:15 S-RCP ND did not come on correctly; DSS 43 will toggle it. 04:16 DSS 43 confirms S-RCP ND is ON and its value is 12.5K 04:17 28 29 28 28 04:20 28 30 29 28 X-LCP ND ON, S-RCP ND OFF 04:23 28 29 29 28 04:25 DSS 43 halted and re-enabled S-LCP ND 04:26 29 29 29 28 S-LCP ND ON 04:28 DSS 43 recommends removing last line in Step-04 of procedure (MFQ=ON) 04:31 9 7 7 7 All channels to sky (S-LCP ND still ON) 04:33 8 10 7 7 X-LCP ND ON, S-LCP ND OFF 04:36 7 7 9 7 S-RCP ND ON, X-LCP ND OFF 04:39 7 7 8 11 X-RCP ND ON, S-RCP ND OFF 04:42 7 7 7 7 All ND OFF 04:43 DSS 43 reports "deep cloud cover, much dust" 04:46 All RSR's stop recording (subchannel 3) 04:50 DSS 43 reports AMB physical temperatures: S1=21.56, S2=21.9, X1=18.81 AMB = ambient load CONSCAN = conical scan tracking 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