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 ---------------------------------------------------------------------------- ORB3700 573 118 953 1989-01-22T02:17:06.385Z 1989-01-22T04:15:37.675Z ORB3701 567 118 953 1989-01-23T02:18:14.117Z 1989-01-23T04:15:42.659Z ORB3702 570 118 953 1989-01-24T02:18:07.096Z 1989-01-24T04:15:53.636Z ORB3704 76 118 953 1989-01-26T03:09:29.320Z 1989-01-26T03:21:18.026Z ORB3705 561 118 953 1989-01-27T02:18:31.036Z 1989-01-27T04:15:58.326Z ORB3706 388 118 953 1989-01-28T02:17:30.746Z 1989-01-28T03:41:47.274Z ORB3707 539 118 953 1989-01-29T02:18:09.736Z 1989-01-29T04:16:03.025Z ORB3708 569 118 953 1989-01-30T02:18:13.460Z 1989-01-30T04:16:12.750Z ORB3709 560 118 953 1989-01-31T02:17:37.181Z 1989-01-31T04:15:55.722Z ORB3710 72 118 953 1989-02-01T03:10:10.662Z 1989-02-01T03:21:31.654Z ORB3712 571 118 953 1989-02-03T02:17:39.612Z 1989-02-03T04:15:46.151Z ORB3713 361 118 953 1989-02-04T02:17:26.596Z 1989-02-04T03:31:01.871Z ORB3714 571 118 953 1989-02-05T02:17:00.337Z 1989-02-05T04:16:09.628Z ORB3715 339 118 953 1989-02-06T03:07:32.039Z 1989-02-06T04:16:30.062Z ORB3716 37 118 953 1989-02-07T02:17:50.446Z 1989-02-07T02:25:22.448Z ORB3717 74 118 953 1989-02-08T03:09:49.438Z 1989-02-08T03:21:28.407Z ORB3718 16 118 953 1989-02-09T03:09:48.419Z 1989-02-09T03:12:10.173Z ORB3719 570 118 953 1989-02-10T02:17:08.400Z 1989-02-10T04:16:10.438Z ORB3721 97 118 953 1989-02-12T02:24:51.351Z 1989-02-12T04:13:29.389Z ORB3751 4 118 953 1989-03-14T03:12:51.263Z 1989-03-14T03:18:22.021Z ORB3752 9 118 953 1989-03-15T03:10:28.231Z 1989-03-15T03:20:51.487Z ORB3753 72 118 953 1989-03-16T03:09:50.202Z 1989-03-16T03:21:29.170Z ORB3754 127 118 953 1989-03-17T02:19:14.428Z 1989-03-17T03:11:21.145Z ORB3755 254 118 953 1989-03-18T02:19:46.899Z 1989-03-18T04:16:10.935Z ORB3757 44 118 953 1989-03-20T02:23:24.108Z 1989-03-20T04:03:10.635Z ORB3758 1 118 953 1989-03-21T03:59:20.099Z 1989-03-21T03:59:20.099Z ORB3759 73 118 953 1989-03-22T03:10:06.038Z 1989-03-22T03:22:32.941Z ORB3760 64 118 953 1989-03-23T03:10:38.006Z 1989-03-23T03:22:45.435Z ORB3789 73 118 953 1989-04-21T03:18:40.095Z 1989-04-21T03:30:19.812Z ORB3790 139 118 953 1989-04-22T02:31:34.595Z 1989-04-22T04:19:33.131Z ORB3791 264 118 953 1989-04-23T02:28:53.598Z 1989-04-23T04:25:12.887Z ORB3792 198 118 953 1989-04-24T02:29:33.329Z 1989-04-24T04:25:27.868Z ORB3793 105 118 953 1989-04-25T02:31:28.329Z 1989-04-25T04:10:14.108Z ORB3794 33 118 953 1989-04-26T03:21:18.421Z 1989-04-26T03:31:23.077Z ORB3795 420 118 953 1989-04-27T02:28:43.052Z 1989-04-27T04:26:24.341Z ORB3796 66 118 953 1989-04-28T03:20:29.549Z 1989-04-28T03:31:59.528Z ORB3797 487 118 953 1989-04-29T02:28:06.543Z 1989-04-29T04:26:50.582Z ORB3798 171 118 953 1989-04-30T02:27:53.036Z 1989-04-30T04:23:03.076Z ORB3799 498 118 953 1989-05-01T02:27:31.533Z 1989-05-01T04:25:38.825Z 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.