nigti HEADAS help file

NAME

nigti - create NICER GTI from time list

USAGE

nigti ingti outfile ...

DESCRIPTION

The nigti task creates a NICER GTI file from a textual list of GTI time ranges.

The input of the task is a list of time ranges, as text. This list can either be a comma-separated list of time ranges on the command line, or a text file with one time range per line.

Each time range describes the start and stop time of an interval. It can be of the form, "A-B" or "A B" where A and B are time specifications.

Time may be specified in several appropriate units. Allowed formats are: p

NICER MET (number of seconds elapsed since the NICER epoch)
UTC ISO format (YYYY-MM-DDThh:mm:ss)
UTC DOY format (YYYY:DDD:hh:mm:ss) where DDD is the day of year

Here are some valid input time ranges:

    2022-01-01T00:00:00-2022-01-01T01:00:00   (UTC time with dash separator)
    2022-01-01T00:00:00 2022-01-01T01:00:00   (UTC time with space separator)
    252806402-252810002                       (MET time with dash separator)    
    252806402 252810002                       (MET time with space separator)

It is also possible to mix and match time formats in the same range, although that may lead to confusion. No extraneous text, other than whitespace, is permitted before the start of the time range, but any text following the time range is ignored.

The task also handles any solitary whitespace, or any empty input file. input as an empty GTI.

If a file input is specified, lines are eliminated if they are empty whitespace, or comment lines beginning with "#", "//" or ";", or any wholeline delimiters consisting of all dashes or equal signs.

The invert parameter specifies that the input time ranges are "bad times," so the resulting output file will be a GTI that inverts the sense of the input.

When setting invert=YES, or the input GTI is empty, the task will need to know a natural time range to consider as good for the whole mission. The task has reasonable defaults for tstart and tstop but they can be modified.

PARAMETERS

ingti=" " [string]: The input GTIs. The input can either be a comma separated list of time ranges, or @filename.lis where filename.lis contains a list of time ranges separated by carriage returns.
(outfile="nicer.gti") [string]: Output GTI file name.
(invert=NO) [boolean]: If no, the inputs are transferred to the output. If YES, the GTI is inverted before writing.
(tstart="0") [string]: A global mission start time, in any acceptable NICER time format.
(tstop="2030-01-01T00:00:00") [string]: A global mission stop time, in any acceptable NICER time format.
(emptygti="APPLY") [string]: A flag that indicates how empty GTIs are handled. A value of "APPLY" indicates a single row with no good time is written to the file. A value of "IGNORE" specifies that no row is written. A value of "APPLY" is recommended because it will ensure compatibility with more downstream software.
(cleanup="YES") [boolean]: If yes, then clean up temporary files. If no, temporary files remain. This is typically for debugging.
(clobber = NO) [boolean]: If the output file already exists, then setting "clobber = yes" will cause it to be overwritten.
(chatter = 1) [integer, 0 - 5]: Controls the amount of informative text written to standard output. Setting chatter = 4 or higher will produce detailed diagnostic output; chatter = 1 prints out a basic diagnostic message. The default is to produce a brief summary on output.
(history = YES) [boolean]: If history = YES, then a set of HISTORY keywords will be written to the header of the specified HDU in the output file to record the value of all the nigti task parameters that were used to produce the output file.

EXAMPLES

Create a GTI with the specified UTC time ranges in 2022.

  nigti "2022-01-05T00:00:00-2022-01-05T01:00:00,2022-01-05T02:00:00 2022-01-05T02:10:00" outfile.gti

Do the same but with MET values.

  nigti "252806402-252810002,252813602-252814202" outfile.gti

Do the same with an input file instead of on the command line. Create a file named infile.lis with these contents.

  2022-01-05T00:00:00-2022-01-05T01:00:00
  2022-01-05T02:00:00 2022-01-05T02:10:00

and execute this command.

  nigti @infile.lis outfile.gti

Use the same file input but consider the file to contain bad times, and create a corresponding GTI file.

nigti @infile.lis outfile.gti invert=YES

LAST MODIFIED