USRA-STI / gdt-fermi

Gamma-ray Data Tools - Fermi mission components
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Add the ability to handle relative time and override CREATOR keyword #9

Open BillCleveland-USRA opened 1 year ago

BillCleveland-USRA commented 1 year ago

Currently when the GbmTte class is being used to generate a new file, there is no method to specify that the time should be relative to trigger time. In addition, if 'CREATOR' is specified within the given header, it should override the one used in the PRIMARY header (and not show up in the extensions).

The current version of GbmTte fails to make the required TZEROn keywords for EVENTS and GTI.

BillCleveland-USRA commented 1 year ago

The use of relative time in the EVENTS and GTI extension should only apply if T0 is specified.
Trigger files: T0 = TRIGTIME (Relative times in EVENTS and GTI) Contiguous TTE files: T0 = TSTART (Relative times in EVENTS only)

TZERO1 and TZERO2 are used in the GTI in the trigger TTE file only. The GTI appears to use absolute time in the continous file version. (TZERO1 and TZERO2 are only specified for the GTI in the triggered TTE section of GBM's FFD).