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Subsections

13.11 PHT-P and PHT-C default responsivities   


Description Parameter:	Section 4.2.1 
Processing Level:	SPD 
Usage in processing:	section 7.4
File Type:		FITS Image
Units:		 	A/W
File names:		PPRESP_01, PPRESP_02,
		 	PC1RESP_01, PC1RESP_02,
		 	PC2RESP_01, PC2RESP_02
Default responsivities are used in case:

For staring mode observations with the PHT-P or PHT-C subsystems, default detector responsivities are not needed as long as at least one FCS measurement was obtained per detector. However, it can happen that no FCS measurements were collected (due to e.g. data dropouts from telemetry loss) or that the quality of the FCS measurement is insufficient (due to e.g. complete saturation). In those cases default responsivities will be applied in the conversion from signal in V/s to an in-band power on the detector in W.

Default detector responsivities are also applied in case of chopped mode observations. For chopped mode observations, the accompanying FCS measurement - which is also in chopped mode between FCS1 and FCS2 - is not used in OLP Version 7 due to the disturbing signal transients between the chopper plateaux.

The detector responsivity is a function of orbital phase. At the end of the science window the responsivities of all detectors are higher than at the beginning. For detectors P3, C100, and C200 two sets of orbital dependencies are provided: one set for observations before rev 150 (files have suffix _01), the other set for rev 150 and later (files have suffix _02). At rev 150 an additional detector curing procedure was introduced sometime after apogee passage which restores the responsivity to the same level as that at the beginning of the science window.

Since the responsivities are provided in A/W, the conversion from V/s to W can only be carried out if the integration capacities Cint associated with a detector are known, see also section 4.2.1. The capacitances are listed in Table 13.5.


  
Table 13.5: Integration capacities associated with detectors
 Detector   Capacitance (As/V)  
P1 $9{\times}10^{-14}$  
P2 $9{\times}10^{-14}$  
P3 $9{\times}10^{-14}$  
C100 $9{\times}10^{-14}$  
C200 $14{\times}10^{-14}$  
SS $5.26{\times}10^{-14}$  
SL $6.3{\times}10^{-14}$  

Notes  
$\bullet$ 1 A/(V/s) = 1 Farad
$\bullet$ For the arrays, capacitances refer to individual pixels.

For all default responsivity tables, the following FITS keywords are common:
NAXIS = 3
TYPE = REAL*4

  
13.11.1 Product PRESP_01/02: PHT default responsivities for P1, P2 and P3 detectors 


AXIS		Length		Description
1		100		Orbital phase: each element corresponds to a phase in the
		 		range from 0.01 to 1.0 in steps of 0.01
2		3		PHT-P detectors, P1,P2,P3
3		2		Default responsivity and uncertainty

  
13.11.2 Product PC1RESP_01/02: PHT default responsivities for the C100 detector 


AXIS		Length		Description
1		100		Orbital phase: each element corresponds to a phase in the
		 		range from 0.01 to 1.0 in steps of 0.01
2		9		C100 pixels, in same order as in SPD
3		2		Default responsivity and uncertainty

  
13.11.3 Product PC2RESP_01/02: PHT default responsivities for the C200 detector 


AXIS		Length		Description
1		100		Orbital phase: each element corresponds to a phase in the
		 		range from 0.01 to 1.0 in steps of 0.01
2		4		C200 pixels, in same order as SPD
3		2		Default responsivity and uncertainty

Note:
$\bullet$ see section 3.4.2 for definition of C-arrays pixel identifiers

next up previous contents
Next: 13.12 Array Illumination by Up: 13 Calibration G Products Previous: 13.10 FCS power calibration

ISOPHOT Data Users Manual, Version 4.1, SAI/95-220/Dc