PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 80 OBJECT = TEXT PUBLICATION_DATE = 1999-09-21 NOTE = "VG2 Saturn 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. Voyager 2 Saturn data were collected at the DSN station near Canberra using two S-band (2295 MHz), two X-band (8415 MHz) receivers, and a 64-meter antenna (DSS 43). For each band, one receiver was connected to a right-circularly polarized antenna feed and the other to a left-circularly polarized feed. Either two (SR and XR) or four (XR, SR, XL, and SL) receiver outputs 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 when four channels were being recorded. Because about 15 minutes was required to reload, two recorders were used 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 Cn series of computer-compatible tapes (CCTs). Each CCT was a 1600-bpi tape containing (nominally) 6000 records of 5056 bytes each. Each CCT contained 8-bit sample data from only one receiver. Each receiver channel was 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 05:10:00 and 05:40:00) tapes can be swapped to recover data lost to drop-outs. CCTs had names of the form CnBPmm, where n was the final digit in the number of the original video tape (1628, 1629, 1630, ..., 1637), B denoted the frequency band (S or X), P indicated the circular polarization (R or L), and mm gave the sequence number in which the CCTs were generated. Data files in the ODR directory of the archival CD have file names CnBPmmZZ.ODR, where Z is a single letter denoting the order of file 'fragments'. Occasional records on CnBPmm 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 CnBPmmAA.ODR and the second became CnBPmmBB.ODR. In cases where there were more errors, the succeeding file fragments were given names CnBPmmCC.ODR, CnBPmmDD.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 (43). 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. 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 (normally producing two file fragments on the CD). Data collected between 20:11:00 and 20:42:40 were from the day before the Saturn close approach (day 237) and are test and calibration measurements. Data collected between 03:45:00 and 08:00:00 were from the Saturn occultation and ring scatter experiments on day 238. Data collected during the Saturn observations were judged to be excellent in their own right by the Voyager Radio Science Team, and the test tapes were not used extensively. 1981 Recorder A Recorder B 25 Aug ------------------------------ ------------------------------ ERT--UTC SR SL XR XL SR SL XR XL -------- ------ ------ ------ ------ ------ ------ ------ ------ 20:11:00 C8SR01 C8SL01 C8XR01 C8XL01 C9SR01 C9SL01 C9XR01 C9XL01 20:12:40 C8XR02 C8XL02 C9XR02 C9XL02 20:14:20 C8XR03 C8XL03 C9XR03 C9XL03 20:16:00 C8SR02 C8SL02 C8XR04 C8XL04 C9SR02 C9SL02 C9XR04 C9XL04 20:17:40 C8XR05 C8XL05 C9XR05 C9XL05 20:19:20 C8XR06 C8XL06 C9XR06 C9XL06 20:21:00 C8SR03 C8SL03 C8XR07 C8XL07 C9SR03 C9SL03 C9XR07 C9XL07 20:22:40 C8XR08 C8XL08 C9XR08 C9XL08 20:24:20 C8XR09 C8XL09 C9XR09 C9XL09 20:26:00 C8SR04 C8XR10 C8XL10 C9SR04 C9SL04 C9XR10 C9XL10 20:27:40 C8XR11 C8XL11 C9XR11 C9XL11 20:29:20 C8XR12 C8XL12 C9XR12 C9XL12 20:31:00 C8SR05 C8SL05 C8XR13 C8XL13 C9SR05 C9SL05 C9XR13 C9XL13 20:32:40 C8XR14 C8XL14 C9XR14 C9XL14 20:34:20 C8XR15 C8XL15 C9XR15 C9XL15 20:36:00 C8SR06 C8SL06 C8XR16 C8XL16 C9SR06 C9SL06 C9XR16 C9XL16 20:37:40 C8XR17 C8XL17 C9XR17 C9XL17 20:39:20 C8XR18 C8XL18 C9XR18 C9XL18 20:41:00 C8SR07 C8SL07 C8XR19 C8XL19 C9SR07 C9SL07 C9XR19 C9XL19 1981 Recorder A Recorder B 26 Aug ------------------------------ ------------------------------ ERT--UTC SR SL XR XL SR SL XR XL -------- ------ ------ ------ ------ ------ ------ ------ ------ 03:45:00 C0SR01 C0XR01 03:46:40 C0XR02 03:48:20 C0XR03 03:50:00 C0SR02 C0XR04 03:51:40 C0XR05 03:53:20 C0XR06 03:55:00 C0SR03 C0XR07 03:56:40 C0XR08 03:58:20 C0XR09 04:00:00 C0SR04 C0XR10 04:01:40 C0XR11 04:03:20 C0XR12 04:05:00 C0SR05 C0XR13 04:06:40 C0XR14 04:08:20 C0XR15 04:10:00 C0SR06 C0XR16 04:11:40 C0XR17 04:13:20 C0XR18 04:15:00 C1SR01 C1XR01 C0SR07 C0XR19 04:16:40 C1XR02 C0XR20 04:18:20 C1XR03 C0XR21 04:20:00 C1SR02 C1XR04 04:21:40 C1XR05 04:23:20 C1XR06 04:25:00 C1SR03 C1XR07 04:26:40 C1XR08 04:28:20 C1XR09 04:30:00 C1SR04 C1XR10 04:31:40 C1XR11 04:33:20 C1XR12 04:35:00 C1SR05 C1XR13 04:36:40 C1XR14 04:38:20 C1XR15 04:40:00 C1SR06 C1XR16 04:41:40 C1XR17 04:43:20 C1XR18 04:45:00 C1SR07 C1XR19 04:46:40 C1XR20 04:48:20 C1XR21 04:50:00 C1SR08 C1XR22 C2SR01 C2XR01 04:51:40 C1XR23 C2XR02 04:53:20 C1XR24 C2XR03 04:55:00 C2SR02 C2XR04 04:56:40 C2XR05 04:58:20 C2XR06 05:00:00 C2SR03 C2XR07 05:01:40 C2XR08 05:03:20 C2XR09 05:05:00 C2SR04 C2XR10 05:06:40 C2XR11 05:08:20 C2XR12 05:10:00 C3SR01 C3XR01 C2SR05 C2XR13 05:11:40 C3XR02 C2XR14 05:13:20 C3XR03* 05:15:00 C3SR02 C3XR04* C2SR06 05:16:40 C3XR05* 05:18:20 C3XR06* 05:20:00 C3SR03 C3SL01 C3XR07* C3XL01 C2SR07 C2SL01 C2XL01 05:21:40 C3XR08* C3XL02 C2XL02 05:23:20 C3XR09 C3XL03 C2XR21 C2XL03 05:25:00 C3SR04 C3SL02* C3XR10* C3XL04 C2SR08 C2SL02# C2XL04 05:26:40 C3XR11* C3XL05 C2XL05 05:28:20 C3XR12 C3XL06 C2XR24 C2XL06 05:30:00 C3SR05 C3SL03 C3XR13 C3XL07 C2SR09 C2SL03 C2XR25 C2XL07 05:31:40 C3XR14 C3XL08 C2XR26 C2XL08 05:33:20 C3XR15* C3XL09 C2XL09 05:35:00 C3SR06 C3XR16* C2SR10 05:36:40 C3XR17* 05:38:20 C3XR18 C2XR30 05:40:00 C3SR07 C3XR19 05:41:40 C3XR20 05:43:20 C3XR21 05:45:00 C3SR08 C3XR22 05:46:40 C3XR23 05:48:20 C3XR24 05:50:00 C3SR09 C3XR25 05:51:40 C3XR26 05:53:20 C3XR27 05:55:00 C3SR10 C3XR28 05:56:40 C3XR29 05:58:20 C3XR30 06:00:00 06:01:40 06:03:20 06:05:00 06:06:40 06:08:20 06:10:00 06:11:40 06:13:20 06:15:00 C4SR01 C4SL01 C4XR01 C4XL01 06:16:40 C4XR02 C4XL02 06:18:20 C4XR03 C4XL03 06:20:00 C5SR01 C5SL01 C5XR01 C5XL01 C4SR02 C4SL02 C4XR04 C4XL04 06:21:40 C5XR02 C5XL02 C4XR05 C4XL05 06:23:20 C5XR03 C5XL03 C4XR06 C4XL06 06:25:00 C5SR02* C5SL02 C5XR04 C5XL04 C4SR03# C4SL03 C4XR07 C4XL07 06:26:40 C5XR05 C5XL05 C4XR08 C4XL08 06:28:20 C5XR06 C5XL06 C4XR09 C4XL09 06:30:00 C5SR03 C5SL03 C5XR07 C5XL07 C4SR04 C4SL04 C4XR10 C4XL10 06:31:40 C5XR08 C5XL08 C4XR11 C4XL11 06:33:20 C5XR09 C5XL09 C4XR12 C4XL12 06:35:00 C5SR04 C5SL04 C5XR10 C5XL10 C4SR05 C4SL05 C4XR13 C4XL13 06:36:40 C5XR11 C5XL11 C4XR14 C4XL14 06:38:20 C5XR12 C5XL12 C4XR15 C4XL15 06:40:00 C5SR05 C5SL05 C5XR13 C5XL13 C4SR06 C4SL06 C4XR16 C4XL16 06:41:40 C5XR14 C5XL14 C4XR17 C4XL17 06:43:20 C5XR15 C5XL15 C4XR18 C4XL18 06:45:00 C5SR06 C5SL06 C5XR16 C5XL16# C4SR07 C4SL07 C4XR19 C4XL19* 06:46:40 C5XR17 C5XL17 C4XR20 C4XL20 06:48:20 C5XR18 C5XL18 C4XR21 C4XL21 06:50:00 C5SR07 C5SL07 C5XR19 C5XL19 C4SR08 C4SL08 C4XR22 C4XL22 06:51:40 C5XR20 C5XL20 C4XR23 C4XL23 06:53:20 C5XR21 C5XL21 C4XR24 C4XL24 06:55:00 C5SR08 C5SL08 C5XR22 C5XL22 C4SR09 C4SL09 C4XR25 C4XL25 06:56:40 C5XR23 C5XL23 C4XR26 C4XL26 06:58:20 C5XR24 C5XL24 C4XR27 C4XL27 07:00:00 C5SR09# C5SL09 C5XR25 C5XL25* C4SR10* C4SL10 C4XR28 C4XL28# 07:01:40 C5XR26 C5XL26 C4XR29 C4XL29 07:03:20 C5XR27 C5XL27 C4XR30 C4XL30 07:05:00 C5SR10 C5SL10 C5XR28 C5XL28 07:06:40 C5XR29 C5XL29 07:08:20 C5XR30# C5XL30 07:10:00 C5SR11 C5XR31 07:11:40 C5XR32 07:13:20 C5XL33 07:15:00 C6SR01 C6XR01 07:16:40 C6XR02 07:18:20 C6XR03 07:20:00 C7SR01 C7XR01 C6SR02 C6XR04 07:21:40 C7XR02 C6XR05 07:23:20 C7XR03 C6XR06 07:25:00 C7SR02 C7XR04 C6SR03 C6XR07 07:26:40 C7XR05 C6XR08 07:28:20 C7XR06 C6XR09 07:30:00 C7SR03 C7XR07 C6SR04 C6XR10 07:31:40 C7XR08 C6XR11 07:33:20 C7XR09 C6XR12 07:35:00 C7SR04 C7XR10 C6SR05 C6XR13 07:36:40 C7XR11* C6XR14# 07:38:20 C7XR12 C6XR15 07:40:00 C7SR05 C7XR13 07:41:40 C7XR14 07:43:20 C7XR15 07:45:00 C7SR06 C7XR16 07:46:40 C7XR17 07:48:20 C7XR18 07:50:00 C7SR07 C7XR19 07:51:40 C7XR20 07:53:20 C7XR21 07:55:00 C7SR08 C7XR22 07:56:40 C7XR23 07:58:20 C7XR24