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 ---------------------------------------------------------------------------- ORB3400 438 118 953 1988-03-28T01:47:08.526Z 1988-03-28T02:33:02.043Z ORB3401 437 118 953 1988-03-29T01:47:18.047Z 1988-03-29T02:33:04.564Z ORB3402 430 118 953 1988-03-30T01:47:27.563Z 1988-03-30T02:33:14.579Z ORB3403 436 118 953 1988-03-31T01:47:38.078Z 1988-03-31T02:33:24.595Z ORB3404 437 118 953 1988-04-01T01:47:46.602Z 1988-04-01T02:33:33.618Z ORB3405 430 118 953 1988-04-02T01:47:57.625Z 1988-04-02T02:33:44.140Z ORB3406 324 118 953 1988-04-03T01:48:08.644Z 1988-04-03T02:22:09.656Z ORB3407 435 118 953 1988-04-04T01:48:20.666Z 1988-04-04T02:34:07.183Z ORB3408 433 118 953 1988-04-05T01:48:32.652Z 1988-04-05T02:34:19.670Z ORB3409 437 118 953 1988-04-06T01:48:45.669Z 1988-04-06T02:34:32.186Z ORB3410 429 118 953 1988-04-07T01:49:18.182Z 1988-04-07T02:34:46.198Z ORB3411 72 118 953 1988-04-08T02:05:29.686Z 1988-04-08T02:17:08.653Z ORB3412 436 118 953 1988-04-09T01:49:28.716Z 1988-04-09T02:35:15.233Z ORB3413 428 118 953 1988-04-10T01:49:45.734Z 1988-04-10T02:34:35.750Z ORB3414 414 118 953 1988-04-11T01:52:14.758Z 1988-04-11T02:35:49.274Z ORB3415 433 118 953 1988-04-12T01:50:19.775Z 1988-04-12T02:36:00.291Z ORB3416 431 118 953 1988-04-13T01:50:35.293Z 1988-04-13T02:36:21.811Z ORB3417 437 118 953 1988-04-14T01:50:51.808Z 1988-04-14T02:36:38.325Z ORB3418 433 118 953 1988-04-15T01:51:16.074Z 1988-04-15T02:36:56.591Z ORB3419 435 118 953 1988-04-16T01:51:35.091Z 1988-04-16T02:37:15.608Z ORB3420 436 118 953 1988-04-17T01:51:55.111Z 1988-04-17T02:37:35.630Z ORB3421 435 118 953 1988-04-18T01:52:15.385Z 1988-04-18T02:37:55.901Z ORB3422 437 118 953 1988-04-19T01:52:29.904Z 1988-04-19T02:38:16.672Z ORB3423 391 118 953 1988-04-20T01:52:57.676Z 1988-04-20T02:34:51.191Z ORB3424 435 118 953 1988-04-21T01:53:19.445Z 1988-04-21T02:38:59.964Z ORB3425 436 118 953 1988-04-22T01:53:41.969Z 1988-04-22T02:39:22.486Z ORB3426 422 118 953 1988-04-23T01:54:03.993Z 1988-04-23T02:39:44.511Z ORB3427 435 118 953 1988-04-24T01:54:27.516Z 1988-04-24T02:40:08.034Z ORB3428 431 118 953 1988-04-25T01:54:51.039Z 1988-04-25T02:40:31.558Z ORB3429 427 118 953 1988-04-26T01:55:15.060Z 1988-04-26T02:40:55.578Z ORB3430 435 118 953 1988-04-27T01:55:40.830Z 1988-04-27T02:41:21.347Z ORB3431 437 118 953 1988-04-28T01:55:59.315Z 1988-04-28T02:41:46.082Z ORB3491 435 118 953 1988-06-27T02:14:12.561Z 1988-06-27T03:00:18.327Z ORB3492 439 118 953 1988-06-28T02:14:16.816Z 1988-06-28T03:00:22.582Z ORB3494 76 118 953 1988-06-30T02:30:36.576Z 1988-06-30T02:42:25.281Z ORB3495 515 118 953 1988-07-01T02:31:29.308Z 1988-07-01T03:00:35.508Z ORB3497 433 118 953 1988-07-03T02:14:36.066Z 1988-07-03T02:59:57.833Z 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.