PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 80 OBJECT = TEXT PUBLICATION_DATE = 1999-09-06 NOTE = "VG1 Saturn DSS 63 Tapes - Time-Ordered List and Anomalies" END_OBJECT = TEXT END Names of ODR files indicate only the sequential order in which CCTs were generated from original MBODRs. This document shows the relationships among file name, times covered, recorder, frequency, and polarization. It should be helpful to persons interested in processing specific parts of the full data set. Note that this document covers only data collected during the Saturn egress (exit) occultation using DSN antenna 63 in Spain. Ingress (entry) data were collected using DSN antenna 43 in Australia and an entirely different data acquisition system. The ingress data are being archived separately. DSS 63 Saturn data were collected using two S-band (2295 MHz) and two X-band (8415 MHz) receivers. For each band, one receiver was connected to a right-circularly polarized antenna feed and the other to a left- circularly polarized feed. The four receiver outputs (XR, SR, XL, and SL) were sampled (8-bits) and recorded in parallel on high-speed video tapes using analog technology. Each analog tape (a Medium-Band Original Data Record, or MBODR) could hold approximately 30 minutes of Saturn data. Because about 15 minutes was required to reload, two recorders were required in order not to have gaps in the data. Operations of Recorder A and Recorder B were staggered so that at least one drive would always be running. The MBODRs were shipped to JPL where data were extracted and written to the VJ series of computer-compatible tapes (CCTs). Each CCT from Saturn was a 1600-bpi tape containing (nominally) 6000 records of 5056 bytes each. Each CCT contained 8-bit sample data from only one receiver. The four receiver channels were originally sampled at 300 ksps; S-band CCTs contained "decimated" samples (rate reduced to 100 ksps), while X-band CCTs retained the original (300 ksps) rate. As a result each S-band digital tape covers 300 seconds, while each X-band digital tape covers only 100 seconds. Analog tape recording suffers from occasional signal drop-outs; hence there are times when the digital sample stream coming from the MBODR was interrupted. Tracking the "sample count" in header words 27-28 is the best way to detect these anomalies. Synchronization was usually recovered only when the other recorder started. When both recorders were operating (e.g., between 04:45:00 and 05:05:00) tapes can be swapped to recover data lost to drop-outs. After the Saturn experiment was completed, it was discovered that Recorder B had a 'stuck' bit; that is, instead of 8-bit accuracy, the data captured using Recorder B have only 3-bit accuracy; the fourth most significant bit never changed value. Users seeking maximum dynamic range should thus avoid Recorder B data whenever possible. CCTs had names of the form VJnnnn, where nnnn was the sequence number in which the CCTs were generated. For Titan and Saturn data, nnnn began at 6000 and ended at about 6660. Data files in the ODR directory of the archival CD have file names VJnnnnCC.ODR, where C is a single letter denoting the order of file 'fragments'. Occasional records on VJnnnn tapes were lost because of damage to or deterioration of the media. When a single record (or one group of contiguous records) was lost, the first part of the file was named VJnnnnAA.ODR and the second became VJnnnnnBB.ODR. In cases where there were more errors, the succeeding file fragments were given names VJnnnnCC.ODR, VJnnnnDD.ODR, etc. Each fragment contains only integral records, but only the first fragment is likely to begin on an integral second mark. The user may choose how to recombine these file fragments before processing the data. The tape and record format is described in document RSC-11-6. Figure RSC-11-6-2 in the document is a sketch of record organization. Pages 2-13 give details on each field. Note that "source station" (word 4, bits 9-16) will be "21" because the CCTs were generated at JPL's CTA 21; there is no indicator within the tape of the source DSN antenna (63). First order analysis of the raw data could be achieved by stripping the first 56 bytes from each record, then concatenating the blocks of 5000 8-bit sample values into files of 30 MB. In fact, several tapes could be concatenated in the same way. Table Description ----------------- Left column gives nominal time of first sample on tape. Columns 2-9 give tape number, where prefix "VJ" is understood (that is, tape VJ6185 starts at 03:35:00). Band/polarization abbreviations are: SR = S-band right-circularly polarized SL = S-band left-circularly polarized XR = X-band right-circularly polarized XL = X-band left-circularly polarized An asterisk (*) beside the tape number indicates the recommended (original) tape choice for processing. A pound sign (#) beside the tape number indicates a tape with at least one known lost record (two file fragments on the CD). The 'at' sign (@) beside a tape number indicates a file that could not be found at the time the archival volume was created. Data collected between 03:35:00 and 07:30:00 were from the Saturn occultation and subsequent ring scatter experiment. Data collected between 16:25:00 and 16:50:00 were for testing and calibration of the data acquisition system. With exception of the anomalies noted above the Saturn data were judged to be excellent in their own right by the Voyager Radio Science Team, and the test tapes were not used extensively. 1980 Recorder A Recorder B 13 Nov ------------------------- ------------------------- ERT--UTC SR SL XR XL SR SL XR XL -------- ---- ---- ---- ---- ---- ---- ---- ---- 03:35:00 6185* 6197* 6209* 6245* 03:36:40 6210* 6246* 03:38:20 6211* 6247* 03:40:00 6186* 6198* 6212* 6248* 03:41:40 6213* 6249* 03:43:20 6214* 6250* 03:45:00 6187* 6199* 6215* 6251* 03:46:40 6216* 6252* 03:48:20 6217* 6253* 03:50:00 6188* 6200* 6218* 6254* 03:51:40 6219* 6255* 03:53:20 6220* 6256* 03:55:00 6189* 6201* 6221* 6257* 03:56:40 6222* 6258* 03:58:20 6223* 6259* 04:00:00 6190* 6202* 6224* 6260* 04:01:40 6225* 6261* 04:03:20 6226* 6262* 04:05:00 6191* 6203* 6227* 6263* 6089 6101 6113 6149 04:06:40 6228* 6264* 6114 6150 04:08:20 6229* 6265* 6115 6151 04:10:00 6192* 6204* 6230* 6266* 6090 6102 6116 6152 04:11:40 6231* 6267* 6117 6153 04:13:20 6232* 6268* 6118 6154 04:15:00 6193* 6205* 6233* 6269* 6091 6103 6119 6155 04:16:40 6234* 6270* 6120 6156 04:18:20 6235* 6271* 6121 6157 04:20:00 6194* 6206* 6236* 6272* 6092 6104 6122 6158 04:21:40 6237* 6273* 6123 6159 04:23:20 6238* 6274* 6124 6160 04:25:00 6195* 6207* 6239* 6275* 6093 6105 6125 6161 04:26:40 6240* 6276* 6126 6162 04:28:20 6241* 6277* 6127 6163 04:30:00 6196* 6208* 6242* 6278* 6094 6106 6128 6164@ 04:31:40 6243* 6279* 6129 6165 04:33:20 6244* 6280* 6130 6166 04:35:00 6095* 6107* 6131* 6167* 04:36:40 6132* 6168* 04:38:20 6133* 6169* 04:40:00 6096* 6108* 6134* 6170* 04:41:40 6135* 6171* 04:43:20 6136* 6172* 04:45:00 6001* 6012* 6023* 6056* 6097 6109 6137 6173 04:46:40 6024* 6057* 6138 6174 04:48:20 6025* 6058* 6139 6175 04:50:00 6002* 6013* 6026* 6059* 6098 6110 6140 6176 04:51:40 6027* 6060* 6141 6177 04:53:20 6028* 6061* 6142 6178 04:55:00 6003* 6014* 6029* 6062* 6099 6111 6143 6179 04:56:40 6030* 6063* 6144 6180 04:58:20 6031* 6064* 6145 6181 05:00:00 6004* 6015* 6032* 6065* 6100 6112 6146 6182 05:01:40 6033* 6066* 6147 6183 05:03:20 6034* 6067* 6148 6184 05:05:00 6005* 6016* 6035* 6068* 05:06:40 6036* 6069* 05:08:20 6037* 6070* 05:10:00 6006* 6017* 6038* 6071* 05:11:40 6039* 6072* 05:13:20 6040* 6073* 05:15:00 6007* 6018* 6041* 6074* 05:16:40 6042* 6075* 05:18:20 6043* 6076* 05:20:00 6008* 6019* 6044* 6077* 05:21:40 6045* 6078* 05:23:20 6046* 6079* 05:25:00 6009* 6020* 6047* 6080* 05:26:40 6048* 6081* 05:28:20 6049* 6082*# 05:30:00 6010* 6021* 6050* 6083* 05:31:40 6051* 6084* 05:33:20 6052* 6085* 05:35:00 6011* 6022* 6053* 6086* 6509 6514 6519 6534 05:36:40 6054* 6087* 6520 6535 05:38:20 6055* 6088* 6521 6536 05:40:00 6510* 6515* 6522* 6537* 05:41:40 6523* 6538* 05:43:20 6524* 6539* 05:45:00 6511* 6516* 6525* 6540* 05:46:40 6526* 6541* 05:48:20 6527* 6542* 05:50:00 6512* 6517* 6528* 6543* 05:51:40 6529* 6544* 05:53:20 6530* 6545* 05:55:00 6381* 6392* 6403* 6436* 6513 6518 6531 6546 05:56:40 6404* 6437* 6532 6547 05:58:20 6405* 6438* 6533 6548 06:00:00 6382* 6393* 6406* 6439* 06:01:40 6407* 6440* 06:03:20 6408* 6441* 06:05:00 6383* 6394* 6409* 6442* 06:06:40 6410* 6443* 06:08:20 6411* 6444* 06:10:00 6384* 6395* 6412* 6445* 06:11:40 6413* 6446* 06:13:20 6414* 6447* 06:15:00 6385* 6396* 6415* 6448* 06:16:40 6416* 6449* 06:18:20 6417* 6450* 06:20:00 6386* 6397* 6418* 6451* 06:21:40 6419* 6452* 06:23:20 6420* 6453* 06:25:00 6387* 6398* 6421* 6454* 06:26:40 6422* 6455* 06:28:20 6423* 6456* 06:30:00 6388* 6399* 6424* 6457* 06:31:40 6425* 6458* 06:33:20 6426* 6459* 06:35:00 6389* 6400* 6427* 6460* 06:36:40 6428*# 6461* 06:38:20 6429* 6462* 06:40:00 6390* 6401* 6430* 6463* 06:41:40 6431* 6464* 06:43:20 6432* 6465* 06:45:00 6391* 6402* 6433* 6466* 6549 6554 6559 6574 06:46:40 6434* 6467* 6560 6575 06:48:20 6435* 6468* 6561 6576 06:50:00 6550* 6555* 6562* 6577* 06:51:40 6563* 6578* 06:53:20 6564* 6579* 06:55:00 6551* 6556* 6565*# 6580* 06:56:40 6566* 6581* 06:58:20 6567* 6582* 07:00:00 6552* 6557* 6568* 6583* 07:01:40 6569* 6584* 07:03:20 6570* 6585* 07:05:00 6469* 6474* 6479* 6494* 6553 6558 6571 6586 07:06:40 6480* 6495* 6572 6587 07:08:20 6481* 6496* 6573 6588 07:10:00 6470* 6475* 6482* 6497* 07:11:40 6483* 6498* 07:13:20 6484* 6499* 07:15:00 6471* 6476* 6485* 6500* 07:16:40 6486* 6501* 07:18:20 6487* 6502* 07:20:00 6472* 6477* 6488* 6503* 07:21:40 6489* 6504* 07:23:20 6490* 6505* 07:25:00 6473* 6478* 6491* 6506* 07:26:40 6492* 6507* 07:28:20 6493* 6508* 16:25:00 6612* 6617* 6622* 6637* 16:26:40 6623* 6638* 16:28:20 6624* 6639* 16:30:00 6613* 6618* 6625* 6640* 16:31:40 6626* 6641* 16:33:20 6627* 6642* 16:35:00 6614* 6619* 6628* 6643* 16:36:40 6629* 6644* 16:38:20 6630* 6645* 16:40:00 6615* 6620* 6631* 6646* 16:41:40 6632* 6647* 16:43:20 6633* 6648* 16:45:00 6616* 6621* 6634* 6649* 16:46:40 6635* 6650* 16:48:20 6636* 6651*