POST Time Marks

A key difficulty has been in establishing common/accurate time registration for the various POST datasets. Time marks have been used to establish the relationships between mission time and UTC time for all flights.

The time marks are produced by turning the sync signal off for about 5 sec then on again during the flight.

The times listed in the files are for the first DROP from high to low AFTER the time mark is completed (that is, after the sync signal is turned on again). See the file time_mark_example.pdf

There are 2 files for each flight: PVM1000_RFxx_9.TXT and MT100_RFxx_9.TXT where xx = flight number.

The PVM files contain the elapsed time for each time mark as recorded by the PVM computer. Note that the PVM computer runs slow by 0.73 s per 10,000 s.

The MT files contain the Mission Time and UTC time (in format hhmmss.s or hmmss.s for h < 10).

Both files also contain the time intervals between marks, for a consistency check and also to relate the PVM computer's time intervals to UTC time intervals.

The MT files for all flights can be found here

The PVM time mark files mentioned above have not been included since those are specific to the PVM and were already used to correct the PVM time coordinate.

Steve Krueger