But for the latest information about the GIS, please consult GIS News and the Calibration Uncertainties . The two GIS detectors have different responses and background. It should be possible, however, to make a combined light curve from GIS2 and GIS3 data which, when analyzed, would not yield misleading timing results. It is also possible to combine two energy spectra from GIS2 and GIS3 and to superpose GIS2 and GIS3 images taking account of correct detector responses. Nearly all GIS data have been taken in PH mode with standard bit assignments.
Temporal resolution depends on bit rate and bit assignment.
Combining data with different bit rates is acceptable, provided the highest temporal resolution is not required throughout - as would be the case when, say, making an image. Changing the bit assignments in PH mode only changes the digital resolution, i.e., the binning, of the data. Data taken in low bit rate can be used. Although the GIS has four modes, only two are used for scientific observations. Only accepted X-ray events are sent to the ground.