PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2007-07-31 NOTE = " E-mail and other messages concerning MGS Radio Science on or about 2002/353." END_OBJECT = TEXT END From aseel@airmail.fltops.jpl.nasa.gov Thu Dec 19 05:25:41 2002 Received: from thorn.fltops.jpl.nasa.gov (thorn.fltops.jpl.nasa.gov [137.228.90.10]) by magellan.stanford.edu (8.11.6/8.11.6) with SMTP id gBJDPev03140; Thu, 19 Dec 2002 05:25:40 -0800 (PST) Received: by thorn.fltops.jpl.nasa.gov; id FAA15010; Thu, 19 Dec 2002 05:25:58 -0800 Received: from airmail1.fltops.jpl.nasa.gov(137.228.96.26) by thorn.fltops.jpl.nasa.gov via smap (V4.2) id xma014992; Thu, 19 Dec 02 05:25:46 -0800 Received: from rsops2.fltops.jpl.nasa.gov (rsops2.fltops.jpl.nasa.gov [137.228.136.22]) by airmail1.fltops.jpl.nasa.gov (Postfix) with ESMTP id 0256E15A9; Thu, 19 Dec 2002 05:23:58 -0800 (PST) Received: (from aseel@localhost) by rsops2.fltops.jpl.nasa.gov (8.10.2+Sun/8.10.2) id gBJDP1X14085; Thu, 19 Dec 2002 13:25:01 GMT Date: Thu, 19 Dec 2002 13:25:01 GMT From: aseel anabtawi Message-Id: <200212191325.gBJDP1X14085@rsops2.fltops.jpl.nasa.gov> Content-Type: text To: undisclosed-recipients:;;@fltops.jpl.nasa.gov Content-Length: 1140 Status: R DSS: 65 RSR: RSR2A Subchannel: 1 Orbit Number: 16898 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-05:31:00 End Record: 2002/353-05:41:00 DSS: 65 RSR: RSR2A Subchannel: 1 Orbit Number: 16899 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-07:29:00 End Record: 2002/353-07:39:00 DSS: 65 RSR: RSR2A Subchannel: 1 Orbit Number: 16900 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-09:26:00 End Record: 2002/353-09:36:00 DSS: 65 RSR: RSR2A Subchannel: 1 Orbit Number: 16901 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-11:24:00 End Record: 2002/353-11:34:00 DSS: 65 RSR: RSR2A Subchannel: 1 Orbit Number: 16902 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-13:22:00 End Record: 2002/353-13:32:00 -------------------------------------------------------------------------- From aseel@airmail.fltops.jpl.nasa.gov Thu Dec 19 10:45:47 2002 Received: from thorn.fltops.jpl.nasa.gov (thorn.fltops.jpl.nasa.gov [137.228.90.10]) by magellan.stanford.edu (8.11.6/8.11.6) with SMTP id gBJIjkv28434; Thu, 19 Dec 2002 10:45:46 -0800 (PST) Received: by thorn.fltops.jpl.nasa.gov; id KAA03205; Thu, 19 Dec 2002 10:46:04 -0800 Received: from airmail1.fltops.jpl.nasa.gov(137.228.96.26) by thorn.fltops.jpl.nasa.gov via smap (V4.2) id xma003070; Thu, 19 Dec 02 10:45:45 -0800 Received: from rsops2.fltops.jpl.nasa.gov (rsops2.fltops.jpl.nasa.gov [137.228.136.22]) by airmail1.fltops.jpl.nasa.gov (Postfix) with ESMTP id 3EA2F15A9; Thu, 19 Dec 2002 10:43:57 -0800 (PST) Received: (from aseel@localhost) by rsops2.fltops.jpl.nasa.gov (8.10.2+Sun/8.10.2) id gBJIj0914524; Thu, 19 Dec 2002 18:45:00 GMT Date: Thu, 19 Dec 2002 18:45:00 GMT From: aseel anabtawi Message-Id: <200212191845.gBJIj0914524@rsops2.fltops.jpl.nasa.gov> Content-Type: text To: undisclosed-recipients:;;@fltops.jpl.nasa.gov Content-Length: 684 Status: R DSS: 25 RSR: RSR2B Subchannel: 1 Orbit Number: 16902 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-13:22:00 End Record: 2002/353-13:32:00 DSS: 25 RSR: RSR2B Subchannel: 1 Orbit Number: 16903 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-15:20:00 End Record: 2002/353-15:29:00 DSS: 25 RSR: RSR2B Subchannel: 1 Orbit Number: 16904 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-17:17:00 End Record: 2002/353-17:27:00 -------------------------------------------------------------------------- From aseel@airmail.fltops.jpl.nasa.gov Thu Dec 19 15:15:27 2002 Received: from thorn.fltops.jpl.nasa.gov (thorn.fltops.jpl.nasa.gov [137.228.90.10]) by magellan.stanford.edu (8.11.6/8.11.6) with SMTP id gBJNFRv04540; Thu, 19 Dec 2002 15:15:27 -0800 (PST) Received: by thorn.fltops.jpl.nasa.gov; id PAA21761; Thu, 19 Dec 2002 15:15:35 -0800 Received: from airmail1.fltops.jpl.nasa.gov(137.228.96.26) by thorn.fltops.jpl.nasa.gov via smap (V4.2) id xma021713; Thu, 19 Dec 02 15:14:46 -0800 Received: from rsops2.fltops.jpl.nasa.gov (rsops2.fltops.jpl.nasa.gov [137.228.136.22]) by airmail1.fltops.jpl.nasa.gov (Postfix) with ESMTP id 7D3FF15A9; Thu, 19 Dec 2002 15:12:57 -0800 (PST) Received: (from aseel@localhost) by rsops2.fltops.jpl.nasa.gov (8.10.2+Sun/8.10.2) id gBJNE1914671; Thu, 19 Dec 2002 23:14:01 GMT Date: Thu, 19 Dec 2002 23:14:01 GMT From: aseel anabtawi Message-Id: <200212192314.gBJNE1914671@rsops2.fltops.jpl.nasa.gov> Content-Type: text To: undisclosed-recipients:;;@fltops.jpl.nasa.gov Content-Length: 912 Status: RO DSS: 24 RSR: RSR2A Subchannel: 1 Orbit Number: 16902 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-13:22:00 End Record: 2002/353-13:32:00 DSS: 24 RSR: RSR2A Subchannel: 1 Orbit Number: 16903 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-15:20:00 End Record: 2002/353-15:29:00 DSS: 24 RSR: RSR2A Subchannel: 1 Orbit Number: 16904 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-17:17:00 End Record: 2002/353-17:27:00 DSS: 24 RSR: RSR2A Subchannel: 1 Orbit Number: 16905 Occultation Sense: i SOE: mm237b.04.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/353-19:15:00 End Record: 2002/353-19:25:00 -------------------------------------------------------------------------- From aseel@godzilla.jpl.nasa.gov Fri Dec 20 15:30:57 2002 Received: from godzilla.jpl.nasa.gov (godzilla.jpl.nasa.gov [137.78.78.95]) by magellan.stanford.edu (8.11.6/8.11.6) with ESMTP id gBKNUvv08683 for ; Fri, 20 Dec 2002 15:30:57 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by godzilla.jpl.nasa.gov (8.9.3/8.9.3) with SMTP id PAA22934 for ; Fri, 20 Dec 2002 15:31:17 -0800 (PST) Message-Id: <200212202331.PAA22934@godzilla.jpl.nasa.gov> Date: Fri, 20 Dec 2002 15:31:17 -0800 (PST) From: Aseel Anabtawi Reply-To: Aseel Anabtawi Subject: DSS 15 To: rsimpson@magellan.stanford.edu MIME-Version: 1.0 Content-Type: TEXT/plain; charset=us-ascii Content-MD5: JbO/7eQGv+ew+dZWWyPRgg== X-Mailer: dtmail 1.2.1 CDE Version 1.2.1 SunOS 5.6 sun4u sparc Content-Length: 3281 Status: R Hello, Below is the latest news regarding DSS-15. I haven't had a chance to write that DR yet, and I was planning on doing it today, but since you report no modulation problems with today's data, should I wait until after the weekend's pass? Regards, Aseel ------------- Begin Forwarded Message ------------- -----Original Message----- From: Gregor, Tim Sent: Thursday, December 19, 2002 8:07 AM To: Snedeker, Charley Subject: RE: MGS RST Instrument Health Report HEA2352A.TXT Chuck, Work is being performed on the encoders during DSS-15's down time today. Regards, "Safety First" ------------- End Forwarded Message ------------- ------------- Begin Forwarded Message ------------- > -----Original Message----- > From: Snedeker, Charley > Sent: Thursday, December 12, 2002 12:37 PM > To: Abbate, Salvatore F > Cc: McCoy, Jim; Haroldsson, Robert; Wert, Michael > Subject: DSS 15 > > Sal, > > FYI > > Copied the following from the GDSCC Weekly... My appologies if you have > already seen it. > > Drive cabinet alignments were performed on the DSS15 antenna on 12/05/02. > This is part of the plan to isolate causes of the MGS radio science data > problem. During alignments, azimuth drive amplifier #3 failed. The > replacement amplifier operated correctly after alignment. Inspection of > cables and connectors for the encoding system did not show signs of > corrosion or damage. Operations Engineers (OE) are working closely with us > to isolate the cause of the ongoing problem. > > Chuck Snedeker > Engineering Services Department > GDSCC > > Safety First! > ------------- End Forwarded Message ------------- ------------- Begin Forwarded Message ------------- -------------------------------------------------------------------------- From: "Abbate, Salvatore F" Subject: FW: DSS-15 Pointing Anomaly Date: Wed, 11 Dec 2002 15:12:49 -0800 FYI > -----Original Message----- > From: Haroldsson, Robert > Sent: Wednesday, December 11, 2002 2:49 PM > To: Abbate, Salvatore F > Cc: Almassy, William T; Wert, Michael; McCoy, Jim > Subject: RE: DSS-15 Pointing Anomaly > > Sal, > > Here is some more information. > > Last week we did a drive cabinet alignment, power supplies and amplifiers. > We did find a bad smplifier. Also we inspected and cleaned all the cables > and connectors for the encoding system. > > Plans : the OE is looking for the spare cards for the data converter, > encoding system. We will replace them when they become available. If we > continue to get excessive EL encoder alarms we will then look at the > encoder again. There has been some conversation as to how the encoders > are mounted and the OE is approaching the CDE on possible modifacations in > the loop. > > That is what is going on. > > Bob Haroldsson, > Digital/Servo Engineering Supervisor > HTSI > (760)255-8229 > rharoldsson@jgld.gdscc.nasa.gov > > Be safe, if you die today your spouse will spend your 401K > > > > -----Original Message----- > From: Abbate, Salvatore F > Sent: Tuesday, December 10, 2002 9:25 AM > To: Haroldsson, Robert > Subject: DSS-15 Pointing Anomaly > > > > Hi Bob > > MGS Radio Science ( Aseel Anabtawi ) called , and asked if we had any new > information about DSS-15 . > > Regards , Sal ------------- End Forwarded Message ------------- -------------------------------------------------------------------------- From aseel@godzilla.jpl.nasa.gov Mon Jan 6 15:44:09 2003 Received: from godzilla.jpl.nasa.gov (godzilla.jpl.nasa.gov [137.78.78.95]) by magellan.stanford.edu (8.11.6/8.11.6) with ESMTP id h06Ni8v14160 for ; Mon, 6 Jan 2003 15:44:08 -0800 (PST) Received: from R2D22k (dialin-141.jpl.nasa.gov [128.149.231.141]) by godzilla.jpl.nasa.gov (8.9.3/8.9.3) with SMTP id PAA18617; Mon, 6 Jan 2003 15:44:47 -0800 (PST) Message-ID: <034c01c2b5de$a2807550$9865fea9@R2D22k> From: "Aseel Anabtawi" To: "Dick Simpson 723-3525" Cc: "Sami Asmar" Subject: Fw: DSS 15 Date: Mon, 6 Jan 2003 15:52:11 -0800 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 Content-Length: 810 Status: R ----- Original Message ----- From: "Snedeker, Charley" To: "Abbate, Salvatore F" Sent: Monday, January 06, 2003 2:41 PM Subject: DSS 15 > Sal, > > Per your phone message, it's great to hear that the "hunting" problem during > occultation is gone. I pulled the following information from the GDSCC > weekly report: > > * On 12/19/02, the DSS15 Elevation Encoder was rotated CCW > 90 degrees. This is in reference to the intermittent problem when the > antenna elevation is below 30 degrees. Troubleshooting had revealed that > the elevation and azimuth position offset switches were intermittent in the > Data Converter Assembly - all appears OK at this time. > > > Chuck Snedeker > Engineering Services Department > GDSCC > > Safety First! > -------------------------------------------------------------------------- From jtwicken@stanford.edu Sat Jan 4 10:22:39 2003 Received: from nova.Stanford.EDU (nova [171.64.90.123]) by magellan.stanford.edu (8.11.6/8.11.6) with ESMTP id h04IMdv16911 for ; Sat, 4 Jan 2003 10:22:39 -0800 (PST) Received: from neptune.Stanford.EDU (neptune.Stanford.EDU [171.64.90.149]) by nova.Stanford.EDU (8.9.3/8.9.3) with ESMTP id KAA13504; Sat, 4 Jan 2003 10:23:17 -0800 (PST) Received: from neptune.Stanford.EDU (joe@localhost) by neptune.Stanford.EDU (8.11.6/8.11.6) with ESMTP id h04INFU03261; Sat, 4 Jan 2003 10:23:15 -0800 (PST) Message-Id: <200301041823.h04INFU03261@neptune.Stanford.EDU> X-Authentication-Warning: neptune.Stanford.EDU: joe owned process doing -bs X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 From: Joe Twicken To: hinson@nova.stanford.edu, joe@nova.stanford.edu, rsimpson@nova.stanford.edu Subject: Re: RSR Notice: /users/z08/procRSR/30031715 In-reply-to: Your message of "Fri, 03 Jan 2003 09:42:52 PST." <200301031742.h03HgqD16672@magellan.stanford.edu> References: <200301031742.h03HgqD16672@magellan.stanford.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sat, 04 Jan 2003 10:23:15 -0800 Content-Length: 1563 Status: RO (1) There is an artifact in carrier power and frequency in the baseline of the 2353132C.RSR recording. The resulting Allan deviation is very high (9.3e-13 at 4 seconds) (2) There was no HGA motion compensation for these recordings >23530531.RSR p 65XR1IRXN101 65XR1IC1XX01 65XR1IF1S101 65XR1IS1T101 65XR1IS1T201 65XR1IS1T301 65XR1IS1T401 65XR1IS1T501 >23530729.RSR p 65XR1IRXN101 65XR1IC1XX01 65XR1IF1S101 65XR1IS1T101 65XR1IS1T201 65XR1IS1T301 65XR1IS1T401 65XR1IS1T501 >23530926.RSR p 65XR1IRXN101 65XR1IC1XX01 65XR1IF1S101 65XR1IS1T101 65XR1IS1T201 65XR1IS1T301 65XR1IS1T401 65XR1IS1T501 >23531124.RSR p 65XR1IRXN101 65XR1IC1XX01 65XR1IF1S101 65XR1IS1T101 65XR1IS1T201 65XR1IS1T301 65XR1IS1T401 65XR1IS1T501 >2353132C.RSR p 25XR1IRXN101 25XR1IC1XX01 25XR1IF1S101 25XR1IS1T101 25XR1IS1T201 25XR1IS1T301 25XR1IS1T401 25XR1IS1T501 >2353132M.RSR p 24XR1IRXN101 24XR1IC1XX01 24XR1IF1S101 24XR1IS1T101 24XR1IS1T201 24XR1IS1T301 24XR1IS1T401 24XR1IS1T501 >23531520.RSR p 25XR1IRXN101 25XR1IC1XX01 25XR1IF1S101 25XR1IS1T101 25XR1IS1T201 25XR1IS1T301 25XR1IS1T401 25XR1IS1T501 >2353152A.RSR p 24XR1IRXN101 24XR1IC1XX01 24XR1IF1S101 24XR1IS1T101 24XR1IS1T201 24XR1IS1T301 24XR1IS1T401 24XR1IS1T501 >23531717.RSR p 25XR1IRXN101 25XR1IC1XX01 25XR1IF1S101 25XR1IS1T101 25XR1IS1T201 25XR1IS1T301 25XR1IS1T401 25XR1IS1T501 >2353171H.RSR p 24XR1IRXN101 24XR1IC1XX01 24XR1IF1S101 24XR1IS1T101 24XR1IS1T201 24XR1IS1T301 24XR1IS1T401 24XR1IS1T501 >23531915.RSR p 24XR1IRXN101 24XR1IC1XX01 24XR1IF1S101 24XR1IS1T101 24XR1IS1T201 24XR1IS1T301 24XR1IS1T401 24XR1IS1T501 -------------------------------------------------------------------------- From jtwicken@stanford.edu Wed Jan 8 12:14:37 2003 Received: from neptune.Stanford.EDU (neptune [171.64.90.149]) by magellan.stanford.edu (8.11.6/8.11.6) with ESMTP id h08KEbv23965 for ; Wed, 8 Jan 2003 12:14:37 -0800 (PST) Received: from neptune.Stanford.EDU (joe@localhost) by neptune.Stanford.EDU (8.11.6/8.11.6) with ESMTP id h08KFFh12900; Wed, 8 Jan 2003 12:15:15 -0800 (PST) Message-Id: <200301082015.h08KFFh12900@neptune.Stanford.EDU> X-Authentication-Warning: neptune.Stanford.EDU: joe owned process doing -bs X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 From: Joe Twicken To: aseel@godzilla.jpl.nasa.gov (Aseel Anabtawi) cc: sami.asmar@jpl.nasa.gov (Sami Asmar), rsimpson@magellan.stanford.edu (Dick Simpson 723-3525), hinson@rocc.stanford.edu (Dave Hinson), len@nova.stanford.edu (len tyler), kusza@stanford.edu (Kerri Kusza) Subject: DSS 24/25 Comparison (2002/353) Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 08 Jan 2003 12:15:14 -0800 Content-Length: 2888 Status: RO Hello Aseel- Three ingress occultations (16902i-16904i) were recorded simultaneously on 2002/353 at both DSS 24 and 25. I have processed each open-loop recording and compared the performance at the two stations. Unfortunately, 16902i at DSS 25 was corrupted by short carrier power and frequency artifacts in the baseline. As a result, the performance at the two stations cannot be meaningfully compared for this occultation. The results for the other two occultations may be found in the tables below. The USO frequency extracted from the recordings at stations 24 and 25 agreed to the milliHertz level for each occultation (Table 1). The SNR for each occultation was better at DSS 25 than DSS 24, the difference ranging from approximately 1 to 2 dB (Table 2). The frequency stability at DSS 25 was better than DSS 24 at integration times less than or equal to 4 seconds; at integration times greater than or equal to 8 seconds the stability at station 25 was marginally better than 24 for occultation 16903i while the stability at 24 was marginally better than 25 for occultation 16904i (Table 3). Joe ****************************************************************************** Table 1 Estimated USO Frequency (Hz); T = 4.096 sec Occ DSS 24 DSS 25 16903i 8423153056.548 8423153056.548 16904i 8423153056.528 8423153056.528 ****************************************************************************** Table 2 Nominal SNR (dB/Hz) Occ DSS 24 DSS 25 16903i 50.1 51.2 16904i 49.5 51.4 ****************************************************************************** Table 3 Allan deviation Occ 16903i: 2002/353 15:20:00-15:29:00 T, sec DSS 24 DSS 25 (2353152A.RSR) (23531520.RSR) 0.512 7.9437e-13 5.7358e-13 1.024 4.6031e-13 3.0793e-13 2.048 2.2592e-13 1.9938e-13 4.096 1.2469e-13 1.2208e-13 8.192 1.1244e-13 1.0209e-13 32.768 9.7173e-14 9.4382e-14 Occ 16904i: 2002/353 17:17:00-17:27:00 T, sec DSS 24 DSS 25 (2353171H.RSR) (23531717.RSR) 0.512 9.1465e-13 6.4278e-13 1.024 4.2891e-13 2.7412e-13 2.048 2.4177e-13 1.9098e-13 4.096 1.5708e-13 1.4839e-13 8.192 1.6028e-13 1.7941e-13 32.768 1.6568e-13 1.6739e-13 ****************************************************************************** -------------------------------------------------------------------------- From aseel@godzilla.jpl.nasa.gov Tue Mar 4 15:26:38 2003 Received: from godzilla.jpl.nasa.gov (godzilla.jpl.nasa.gov [137.78.78.95]) by magellan.stanford.edu (8.11.6/8.11.6) with ESMTP id h24NQbZ00417; Tue, 4 Mar 2003 15:26:37 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by godzilla.jpl.nasa.gov (8.9.3/8.9.3) with SMTP id PAA22988; Tue, 4 Mar 2003 15:27:23 -0800 (PST) Message-Id: <200303042327.PAA22988@godzilla.jpl.nasa.gov> Date: Tue, 4 Mar 2003 15:27:23 -0800 (PST) From: Aseel Anabtawi Reply-To: Aseel Anabtawi Subject: Re: DSS-15 Antenna ( ISA z78518 ) To: SAbbate@jftl.jpl.nasa.gov, rsimpson@magellan.stanford.edu, joe@nova.stanford.edu, kusza@magellan.stanford.edu MIME-Version: 1.0 Content-Type: TEXT/plain; charset=us-ascii Content-MD5: DX7Tw3QQUZ/PWGGYWNR4rQ== X-Mailer: dtmail 1.2.1 CDE Version 1.2.1 SunOS 5.6 sun4u sparc Content-Length: 3923 Status: O Hello Sal, I haven't seen reports of modulation problems at DSS-15 for some time now, but I'm forwarding this to Stanford to check that it's OK with them to close this ISA. I believe that they weren't satisfied with the station's explanation on what was done to solve the problem, and neither was I or you. Regards, Aseel ------------- Begin Forwarded Message ------------- -------------------------------------------------------------------------- From: "Abbate, Salvatore F" To: "Anabtawi, Aseel" Cc: "Short, Alan B" Subject: DSS-15 Antenna ( ISA z78518 ) Date: Tue, 4 Mar 2003 11:30:25 -0800 Hi Aseel Al Short is inquiring as to the status of DSS-15 Antenna ( ISA z78518 ). If Stanford is not seeing any problems , I think we could close out this ISA . Thanks , Sal Sal, FYI Copied the following from the GDSCC Weekly... My appologies if you have already seen it. Drive cabinet alignments were performed on the DSS15 antenna on 12/05/02. This is part of the plan to isolate causes of the MGS radio science data problem. During alignments, azimuth drive amplifier #3 failed. The replacement amplifier operated correctly after alignment. Inspection of cables and connectors for the encoding system did not show signs of corrosion or damage. Operations Engineers (OE) are working closely with us to isolate the cause of the ongoing problem. Chuck Snedeker Engineering Services Department GDSCC Safety First! Sal, Per your phone message, it's great to hear that the "hunting" problem during occultation is gone. I pulled the following information from the GDSCC weekly report: * On 12/19/02, the DSS15 Elevation Encoder was rotated CCW 90 degrees. This is in reference to the intermittent problem when the antenna elevation is below 30 degrees. Troubleshooting had revealed that the elevation and azimuth position offset switches were intermittent in the Data Converter Assembly - all appears OK at this time. Chuck Snedeker Engineering Services Department GDSCC Safety First! Sal, What's the current status of this? The last status I got was on 1/8/03 saying they were still looking into the problem. Al ISA z78518 (26 Nov 2002) Since about 2002/273 we have been seeing 0.1-0.2 dB approximately 7 s amplitude modulation on carrier signals collected using open-loop radio science equipment at DSS 15 (e.g., 2002/326-14:03:00 and 2002/327-13:36:00). There have been instances when the amplitude was much larger (1.0-2.0 dB peak-to-peak 2002/329-20:31:00) and a few cases when the period was measurably different (but usually in the range 5-9 s). The data from 2002/329 appear to have both the 7 s period and a 55 s period. A handful of orbits per week have been affected, some weeks having no anomalies. No other antennas have shown the same anomaly. When open loop data have been collected in parallel at a second DSS, no anomalies were seen in the carrier level at the second station. Other dates and times of anomalous DSS 15 signal include (these are start times for recording; the anomalous signal typically lasts 5-7 minutes before occultation): 2002/272-13:26:00 2002/273-13:42:00 2002/273-14:56:00 2002/274-14:28:00 2002/275-14:00:00 2002/277-13:05:00 2002/291-14:29:00 2002/298-13:14:00 2002/305-13:56:00 2002/314-21:33:00 2002/314-21:33:00 2002/317-14:17:00 2002/317-16:15:00 2002/319-13:22:00 2002/319-17:17:00 ============================================ Alan B. Short - DSN Network Operations Project Engineer Mars Exploration, Stardust, Genesis, and Ulysses Missions 2500 E. Foothill Blvd., Suite 400 M/S 507-120 Pasadena, CA 91107 Phone - (626) 584-4447 FAX - (626) 584-4561 Cell - (760) 985-1019 e-mail - ashort@jftl.jpl.nasa.gov "Never argue with an idiot. They drag you down to their level then beat you with experience. ============================================ ------------- End Forwarded Message ------------- -------------------------------------------------------------------------- From rsimpson@magellan.stanford.edu Tue Mar 4 16:44:34 2003 Received: (from rsimpson@localhost) by magellan.stanford.edu (8.11.6/8.11.6) id h250iWq00730; Tue, 4 Mar 2003 16:44:32 -0800 (PST) Date: Tue, 4 Mar 2003 16:44:32 -0800 (PST) From: Dick Simpson 723-3525 Message-Id: <200303050044.h250iWq00730@magellan.stanford.edu> To: SAbbate@jftl.jpl.nasa.gov, aseel@godzilla.jpl.nasa.gov, joe@nova.stanford.edu, kusza@magellan.stanford.edu, rsimpson@magellan.stanford.edu Subject: Re: DSS-15 Antenna ( ISA z78518 ) Content-Length: 861 >I haven't seen reports of modulation problems at DSS-15 for >some time now, but I'm forwarding this to Stanford to check >that it's OK with them to close this ISA. I believe that they >weren't satisfied with the station's explanation on what was >done to solve the problem, and neither was I or you. I agree that the DSS 15 problem seems to have been cured. As you noted, the news we got was about seeking solutions and then about rotating the elevation encoder. But nothing that definitively closed the ISA. This may be another case in which the repairs were done but communication back to the originator failed; and we now (for whatever real reason) can agree that the passage of time has brought us to a point where we can agree on closure. Which is good, because now (and for the past 3 months) DSS 54 seems to be misbehaving.