PVO Ion Mass Spectrometer high-resolution data are stored in single-orbit ASCII files. All of the data files have the same internal structure, which is described by the single format file OIMSDATA.FMT. File structure characteristics which may vary from file to file (# of records, start/stop time, etc.) are described in the individual PDS label files (*.LBL). Columns in all data files: ======================================================= name type description ------------------------------------------------------- PVO TIME char Date and time in format YYDOY FSEC, where YY is the year, DOY is the day-of-year & FSEC is the decimal second-of-day DWELL int Dwell time (time interval between samples, msec) DWELL = (TIME - UT)*1000/(n-1) BITS int Telemetry bit rate LAT float Venusian Latitude LON float Venusian Longitude ALT float Altitude SZA float Solar Zenith Angle SHA float Solar Hour Angle
MASS1 int Mass of Sample 1 DEN1 float Number density of Sample 1 MASS2 int Mass of Sample 2 DEN2 float Number density of Sample 2 . . . . . . . . . MASS55 int Mass of Sample 55 DEN55 float Number density of Sample 55 The values 999 and 9.9999e+04 are the missing data values for mass and density respectively. The value 99999.999 is the missing data value for the second-of-day part of the time column. Negative values in a density column indicate flagged (unreliable) data values. Data Files (.TAB extension) The high-resolution data files on this disk are ASCII table files, each having 118 columns and record length 953 bytes. Information about the individual files (number of records, start and stop times, etc.) can be obtained from the PDS label file accompanying each *.TAB file. This label file has the same filename as the data file but with .TAB replaced by .LBL. List of data files: ============================================================================ Name Records Cols Len Start Stop ---------------------------------------------------------------------------- ORB1500 1 118 953 1983-01-14T01:41:53.470Z 1983-01-14T01:41:53.470Z ORB1501 509 118 953 1983-01-15T00:41:50.541Z 1983-01-15T01:41:41.758Z ORB1502 473 118 953 1983-01-16T00:41:47.232Z 1983-01-16T01:41:36.298Z ORB1503 519 118 953 1983-01-17T00:41:36.722Z 1983-01-17T01:41:27.917Z ORB1504 312 118 953 1983-01-18T00:41:28.004Z 1983-01-18T01:41:15.028Z ORB1505 504 118 953 1983-01-19T00:41:24.239Z 1983-01-19T01:34:19.675Z ORB1506 459 118 953 1983-01-20T00:41:16.780Z 1983-01-20T01:41:07.833Z ORB1507 318 118 953 1983-01-21T00:41:08.163Z 1983-01-21T01:40:55.188Z ORB1508 485 118 953 1983-01-22T00:41:06.885Z 1983-01-22T01:40:57.708Z ORB1509 316 118 953 1983-01-23T00:41:00.911Z 1983-01-23T01:40:48.936Z ORB1510 477 118 953 1983-01-24T00:40:59.436Z 1983-01-24T01:40:51.458Z ORB1511 319 118 953 1983-01-25T00:40:57.151Z 1983-01-25T01:40:45.176Z ORB1512 535 118 953 1983-01-26T00:40:53.013Z 1983-01-26T01:40:44.041Z ORB1514 269 118 953 1983-01-28T00:47:00.743Z 1983-01-28T01:40:48.766Z ORB1515 481 118 953 1983-01-29T00:40:50.951Z 1983-01-29T01:40:48.523Z ORB1516 285 118 953 1983-01-30T00:41:00.709Z 1983-01-30T01:40:38.733Z ORB1517 479 118 953 1983-01-31T00:40:51.410Z 1983-01-31T01:40:48.470Z ORB1518 317 118 953 1983-02-01T00:40:58.654Z 1983-02-01T01:40:46.678Z ORB1519 570 118 953 1983-02-02T00:40:57.902Z 1983-02-02T01:40:48.929Z ORB1520 567 118 953 1983-02-03T00:40:56.014Z 1983-02-03T01:40:53.313Z ORB1521 571 118 953 1983-02-04T00:40:59.532Z 1983-02-04T01:40:50.508Z ORB1532 254 118 953 1983-02-15T00:41:46.091Z 1983-02-15T01:41:28.878Z ORB1537 260 118 953 1983-02-20T00:42:11.452Z 1983-02-20T01:41:48.929Z ORB1538 370 118 953 1983-02-21T00:42:12.426Z 1983-02-21T01:42:02.253Z ORB1539 257 118 953 1983-02-22T00:42:23.356Z 1983-02-22T01:41:57.900Z ORB1540 368 118 953 1983-02-23T00:42:21.452Z 1983-02-23T01:42:12.484Z ORB1541 247 118 953 1983-02-24T00:42:26.537Z 1983-02-24T01:42:10.824Z ORB1544 262 118 953 1983-02-27T00:42:35.244Z 1983-02-27T01:42:19.532Z ORB1545 360 118 953 1983-02-28T00:42:42.465Z 1983-02-28T01:42:33.627Z ORB1546 259 118 953 1983-03-01T00:42:52.655Z 1983-03-01T01:42:24.885Z ORB1547 485 118 953 1983-03-02T00:42:45.479Z 1983-03-02T01:42:35.466Z ORB1548 253 118 953 1983-03-03T00:43:00.535Z 1983-03-03T01:42:30.516Z ORB1549 296 118 953 1983-03-04T00:44:15.416Z 1983-03-04T01:42:31.080Z ORB1550 374 118 953 1983-03-05T00:42:49.600Z 1983-03-05T01:42:41.090Z ORB1553 250 118 953 1983-03-08T00:43:02.446Z 1983-03-08T01:42:41.443Z ORB1554 364 118 953 1983-03-09T00:43:39.532Z 1983-03-09T01:42:42.988Z ORB1555 260 118 953 1983-03-10T00:42:50.616Z 1983-03-10T01:42:31.091Z ORB1556 262 118 953 1983-03-11T00:42:43.652Z 1983-03-11T01:42:42.178Z ORB1557 371 118 953 1983-03-12T00:42:45.239Z 1983-03-12T01:42:36.728Z ORB1558 256 118 953 1983-03-13T00:42:45.314Z 1983-03-13T01:42:18.358Z ORB1560 255 118 953 1983-03-15T00:42:34.422Z 1983-03-15T01:42:09.715Z ORB1561 341 118 953 1983-03-16T00:42:29.781Z 1983-03-16T01:42:20.064Z ORB1562 249 118 953 1983-03-17T00:42:18.569Z 1983-03-17T01:41:59.107Z ORB1563 250 118 953 1983-03-18T00:44:37.668Z 1983-03-18T01:41:57.172Z ORB1564 375 118 953 1983-03-19T00:42:09.183Z 1983-03-19T01:42:00.671Z ORB1565 258 118 953 1983-03-20T00:41:55.274Z 1983-03-20T01:41:38.810Z ORB1566 363 118 953 1983-03-21T00:41:52.811Z 1983-03-21T01:41:43.843Z ORB1567 232 118 953 1983-03-22T00:42:04.918Z 1983-03-22T01:41:19.910Z ORB1568 336 118 953 1983-03-23T00:41:33.491Z 1983-03-23T01:41:24.217Z ORB1569 280 118 953 1983-03-24T00:46:24.334Z 1983-03-24T01:41:12.657Z ORB1570 381 118 953 1983-03-25T00:41:14.123Z 1983-03-25T01:41:04.998Z ORB1571 339 118 953 1983-03-26T00:41:00.492Z 1983-03-26T01:40:51.518Z ORB1574 343 118 953 1983-03-29T00:40:27.508Z 1983-03-29T01:40:18.533Z ORB1576 366 118 953 1983-03-31T00:39:56.139Z 1983-03-31T01:39:46.714Z ORB1577 372 118 953 1983-04-01T00:39:43.537Z 1983-04-01T01:39:34.562Z ORB1578 494 118 953 1983-04-02T00:41:58.888Z 1983-04-02T01:39:19.011Z ORB1579 537 118 953 1983-04-03T00:39:12.791Z 1983-04-03T01:39:04.116Z ORB1580 571 118 953 1983-04-04T00:38:56.294Z 1983-04-04T01:38:53.615Z ORB1581 522 118 953 1983-04-05T00:38:41.792Z 1983-04-05T01:38:32.911Z ORB1582 570 118 953 1983-04-06T00:38:27.901Z 1983-04-06T01:38:19.115Z ORB1583 550 118 953 1983-04-07T00:38:12.312Z 1983-04-07T01:38:03.334Z ORB1584 542 118 953 1983-04-08T00:37:53.517Z 1983-04-08T01:37:44.541Z ORB1585 453 118 953 1983-04-09T00:37:39.718Z 1983-04-09T01:37:31.041Z ORB1586 152 118 953 1983-04-10T00:52:06.959Z 1983-04-10T01:16:12.212Z Catalog Files (.CAT extension) Catalog data, which includes instrument, dataset, mission and spacecraft descriptions, can be found in the *.CAT files in the CATALOG directory on this disk.