Subsections

• 14.2.1 Product PTIMEDEP: PHT calibration time dependency

14.2 Observation Time Dependent Calibration

Description Parameter:	Section 7.10.7
Processing Level:	SPD 
Usage in processing:	Section 7.10.7
File Type: 		Binary FITS table
File names:		PTIMEDEP

During the mission two events took place that directly affected calibration parameters of the instrument:

• the change in the illumination properties of the TRS2 of FCS1 which took place in the activation window of revolution 94. The illumination power for the same electrical power applied to the FCS increased by approximately a factor two. The cause of the change is not clear. The change in FCS properties requires different calibration parameters for FCS related calibrations of P3, C100 and C200.
• the addition of an extra curing procedure for detectors P3, C100 and C200 during the otherwise idle telescope time in ground station handover between VILSPA and Goldstone sometime after the apogee passage of ISO. The extra curing was introduced on rev 150 and affects the orbit dependent responsivity of the three detectors.

Consequently, the OLP must use different sets of Cal-G files depending on the date and time of the observation. This calibration file lists the names of the Cal-G files that are affected together with the date and time when the change took place. Depending on the time of the observation the appropriate Cal-G files are selected.

14.2.1 Product PTIMEDEP: PHT calibration time dependency

Binary FITS table with record length 80. The record fields are:

Field	 Offset	Number	Type	Description
CALGROOT 0	1	C*12	Root name: referred to when file is opened
CALGFILE 12	1	C*12	Corresponding filename
CALGTIME 24	1	C*11	Time from which this file applies
				in yydddhhmmss
CALGCOMM 35	1	C*45	Optional comment