GTI¶

class gammapy.data.GTI(table)[source]¶

Bases: object

Good time intervals (GTI) Table.

Data format specification: GTI

Note: at the moment dead-time and live-time is in the EVENTS header … the GTI header just deals with observation times.

Parameters:	table : `Table` GTI table

Examples

Load GTIs for a H.E.S.S. event list:

>>> from gammapy.data import GTI
>>> gti = GTI.read('$GAMMAPY_DATA/hess-dl3-dr1//data/hess_dl3_dr1_obs_id_023523.fits.gz')
>>> print(gti)
GTI info:
- Number of GTIs: 1
- Duration: 1687.0 s
- Start: 53343.92234009259 MET
- Start: 2004-12-04T22:08:10.184(TT)
- Stop: 53343.94186555556 MET
- Stop: 2004-12-04T22:36:17.184(TT)

Load GTIs for a Fermi-LAT event list:

>>> gti = GTI.read("$GAMMAPY_DATA/fermi-3fhl-gc/fermi-3fhl-gc-events.fits.gz")
>>> print(gti)
GTI info:
- Number of GTIs: 39042
- Duration: 183139597.9032163 s
- Start: 54682.65603794185 MET
- Start: 2008-08-04T15:44:41.678(TT)
- Stop: 57236.96833546296 MET
- Stop: 2015-08-02T23:14:24.184(TT)

Attributes Summary

`time_delta`	GTI durations in seconds (`Quantity`).
`time_ref`	Time reference (`Time`).
`time_start`	GTI start times (`Time`).
`time_stop`	GTI end times (`Time`).
`time_sum`	Sum of GTIs in seconds (`Quantity`).

Methods Summary

`copy`(self)
`create`(start, stop[, reference_time])	Creates a GTI table from start and stop times.
`read`(filename, \\kwargs)	Read from FITS file.
`select_time`(self, time_interval)	Select and crop GTIs in time interval.
`stack`(self, other)	Stack with another GTI.
`union`(self)	Union of overlapping time intervals.

Attributes Documentation

time_delta¶: GTI durations in seconds (Quantity).

time_ref¶: Time reference (Time).

time_start¶: GTI start times (Time).

time_stop¶: GTI end times (Time).

time_sum¶: Sum of GTIs in seconds (Quantity).

Methods Documentation

copy(self)[source]¶

classmethod create(start, stop, reference_time='2000-01-01')[source]¶

Creates a GTI table from start and stop times.

Parameters:	start : `Quantity` start times w.r.t. reference time stop : `Quantity` stop times w.r.t. reference time reference_time : `Time` the reference time to use in GTI definition

classmethod read(filename, **kwargs)[source]¶

Read from FITS file.

Parameters:	filename : `pathlib.Path`, str Filename

select_time(self, time_interval)[source]¶

Select and crop GTIs in time interval.

Parameters:	time_interval : `astropy.time.Time` Start and stop time for the selection.
Returns:	gti : `GTI` Copy of the GTI table with selection applied.

stack(self, other)[source]¶

Stack with another GTI.

This simply changes the time reference of the second GTI table and stack the two tables. No logic is applied to the intervals.

Parameters:	other : `GTI` GTI to stack to self
Returns:	new_gti : `GTI` New GTI

union(self)[source]¶

Union of overlapping time intervals.

Returns a new GTI object.

Intervals that touch will be merged, e.g. (1, 2) and (2, 3) will result in (1, 3).