XMM-Newton Science Analysis System


hkgtigen (hkgtigen-1.15) [xmmsas_20190531_1155-18.0.0]

Motivation

The scientific quality of data acquired with any instrument is usually directly related to the values of its key housekeeping (HK) parameters during the data taking period. Events that were detected during periods when one or more of those parameters was out of valid boundaries must therefore not be taken into account in the generation of images, spectra, and rate curves. This is achieved by filtering out the “bad” events with one or more Good-Time-Interval (GTI) data sets before the product generation takes place. An event is considered to be valid if its arrival time is within one of the GTIs in the set. For more details on this issue, please consult the descriptions of task evselect and package selectlib.

hkgtigen generates for a specified instrument a single GTI data set from a list of given HK parameter validity intervals. These are read from the Current Calibration File (CCF) constituent HKParmInt through the Calibration Access Layer (CAL) and can optionally be augmented by user-specified validity ranges. The created GTI set is applicable to all science data from that instrument in one Observation Data File (ODF). hkgtigen makes use of the generic task tabgtigen for the actual generation of the GTI data set.