PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 1999-09-07 NOTE = " E-mail and other messages concerning MGS Radio Science on or about 1996/332." END_OBJECT = TEXT END From trish@qmail.jpl.nasa.gov Tue Nov 19 13:53:19 1996 Message-Id: Date: 19 Nov 1996 13:48:01 -0800 From: "Trish Priest" Subject: FWD>Re-send of previous mes To: "Len Tyler" Cc: "Richard Simpson" X-Mailer: Mail*Link SMTP-QM 3.0.2 Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; Name="Message Body" Content-Transfer-Encoding: quoted-printable Status: RO Mail*Link=AE SMTP FWD>Re-send of previous message Below is the explanation from Bill Adams about cross strapping. -Trish ------------------------------------- When we just send a command to turn the modulation off, a latching relay in the MOT is released, disconnecting the telemetry signal from the summing amplifier in the phase modulator assembly. This relay/switch "leaks" a little, modulating the carrier at about 1! modulation index (0.001 dB carrier suppression) and the subcarrier peaks are about 35 dB below the carrier. We can further suppress any modulation by switching the telemetry input to an inactive source. Input switching is handled by the Cross Strap Unit (XSU), hence the reference to cross strapping. If we take a nominal case where the unit is in the "uncrossed" position and switch it to "crossed" without changing anything else, we're effectively hooking the "OFF" side of the XSU up to the telemetry input of the MOT. This is the only way to get "pure" carrier on the downlink. You may not care about the leakage signal. Bill Diener preferred us to get rid of it when he was here doing Allan deviation testing on the USO/MOT combinations. We're planning on building an SSF for C02 that puts the proper commands in to establish this mode during the USO test (at times specified in the skeleton pef). If that is not what you want, let me know. Note, this does not keep us from recording spacecraft engineering or PDS telemetry during your test. Only the RF downlink is effected. Bill Adams ( B^ ll ) --------------------------------------- From trish@qmail.jpl.nasa.gov Tue Nov 26 23:31:01 1996 Message-Id: Date: 26 Nov 1996 23:26:42 -0800 From: "Trish Priest" Subject: USO Test #1 To: "Richard Simpson" , "Len Tyler" Cc: "Sami Asmar" , "David Hinson" X-Mailer: Mail*Link SMTP-QM 3.0.2 Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; Name="Message Body" Content-Transfer-Encoding: quoted-printable Status: RO Mail*Link=AE SMTP USO Test #1 Hello, Len and Dick, The USO Test went very well as far as I can tell. The signal was about 50 dB above the noise floor. No spurs that I can see. No DSN problems. 04:46 UTC ERT - DSP to run - No signal because we are still 2-way. 05:00 - Went 1-way 05:01 to 05:07:30 - changed the attenuators 4 times to get a good quantization spread. (Will use Sal's program next time.) 07:00:25 - Back to 2-way So the data between 05:07:30 to 07:00:00 should be clean. (5000 sps, 2kHz filter, 12-bit, mode 2) -Trish ---------------------------------------------------------------- From rsimpson Wed Nov 27 05:16:34 1996 Date: Wed, 27 Nov 96 05:16:33 -0800 From: rsimpson (Richard Simpson) To: trish@qmail.jpl.nasa.gov Subject: Re: USO Test #1 Cc: rsimpson Status: R Thanks. I'll put in a query that covers slightly more than the one-way time. Pulled out the SOE and SFOS before heading home last night; if remote ops hadn't been there, it looked as though the right things were in the schedule. Good work. ----------------------------------------------------------------- From joe Fri Nov 29 11:42:27 1996 Received: from neptune.stanford.edu. (neptune.Stanford.EDU [36.10.0.149]) by nova.stanford.edu (8.7.1/8.7.1) with SMTP id LAA30309; Fri, 29 Nov 1996 11:42:25 -0800 (PST) Date: Fri, 29 Nov 1996 11:42:25 -0800 (PST) From: Joe Twicken Message-Id: <199611291942.LAA30309@nova.stanford.edu> To: hinson@nova.stanford.edu, len@nova.stanford.edu, rsimpson@nova.stanford.edu Subject: USO Test #1 Results Status: RO I have processed the data from USO test #1. The test was conducted at DSS 65 on 96/332. Data were recorded at 5 kHz (with 4 interleaved A/D's each at 1250 Hz) for two hours. There were 96 missing ODS records (the total number of records was 36500). I used the spk_c_961111-970228 SP-kernel file to steer the data; this file was generated post-TCM1. I estimated the USO frequency to be 8423152903.81 Hz. The rate of change of USO frequency with time continues to decrease. The SNR was ~48 dB/Hz. Allan deviation estimates were made despite the large number of missing records which adversely affect the Allan deviation, particularly at the shorter integration times. The AD estimates are: t (sec) AD ------ ---------- 1.6384 7.6344e-13 3.2768 3.1894e-13 6.5536 1.8090e-13 26.2144 1.4131e-13 Plots are in the notebook in room 222... Joe ------------------------------------------------------------------- From rsimpson Sat Nov 30 13:32:48 1996 Date: Sat, 30 Nov 96 13:32:46 -0800 From: rsimpson (Richard Simpson) To: trish@qmail.jpl.nasa.gov Subject: USO Test Data Cc: hinson@nimbus, joe@nova, len@nova, rsimpson Status: R Can we get a retransmission of data from the DSS 65 USO test on 1996/332? We'd like to see whether the missing record count can be reduced by a retransmission. ------------------------------------------------------------------- From trish@qmail.jpl.nasa.gov Mon Dec 2 14:21:33 1996 Message-Id: Date: 2 Dec 1996 14:17:11 -0800 From: "Trish Priest" Subject: FWD>USO Test Retransmission To: "Richard Simpson" Cc: "Joe Twicken" X-Mailer: Mail*Link SMTP-QM 3.0.2 Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; Name="Message Body" Content-Transfer-Encoding: quoted-printable Status: RO Mail*Link=AE SMTP FWD>USO Test Retransmission -------------------------------------- Date: 12/2/96 2:23 PM From: Trish Priest Hello, Dave, The USO Test on Nov. 26th went very well. Please pass on our thanks to station 65. Some of the data, however, didn't make it from our equipment at the station to the Project Database. Radio Science would like to retransmit the data from the USO Test during the next DSS 65 track. This occurs on DOY 342 (Saturday, Dec. 7th). The Radio Science Support Team performs the retransmission using remote operations, so the station personnel only have to put the DSP in the link. Belinda says that adding the DSP to the link for that pass should not trigger a regeneration of the DKF or the SOE. If there are any problems or comments about performing the retransmission, please let me know. In the future I will request retransmissions for most USO Tests at the beginning of the sequencing process. Thanks. -Trish ------------------------------------------------------------------- From trish@qmail.jpl.nasa.gov Mon Dec 2 14:31:46 1996 Message-Id: Date: 2 Dec 1996 14:28:57 -0800 From: "Trish Priest" Subject: Re: Mail Back Up To: "Richard Simpson" X-Mailer: Mail*Link SMTP-QM 3.0.2 Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; Name="Message Body" Content-Transfer-Encoding: quoted-printable Status: RO Reply to: RE>>Mail Back Up Hello, Dick, I just sent you a message about the retransmission. The pass is from 1:00 to 5:00 AM next Saturday. There are only two passes at 65 between now and the end of December because of Pathfinder launch. -Trish