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2.2 Flux Reproducibility for Point Sources

The following Table 2.3 provides the flux reproducibility both for bright and faint sources. The bright source was measured in standard off-on mode, while the faint sources were measured in optimised faint source observing modes: telescope nodding for PHT-P and mini-map for PHT-C.

The flux reproducibility, a relative photometric accuracy, is not only determined by the detector stability, but also, in particular for wavelengths $\ge 100 
\mu$m by the structure of the sky background, since, due to the rotation of the focal plane on the sky, different background fields are seen at different times.


 
Table 2.3:   1 $\sigma$ Flux Reproducibility per Detector for Bright and Faint Fluxes from Monitoring Programs. For the wavelength range of the detector system, please refer to Table 1.1.
         
detector target flux standard deviation no. of meas.
      1 $\sigma$  
    [Jy] [%]  
         
P1 NGC 6543 8 5 15
P1 HD 172323 0.085 10 23
P2 NGC 6543 100 2 14
P2 HR 5986 0.67 12 15
P3 NGC 6543 100 7 15
P3 HR 7310 0.67 7 15
C100 NGC 6543 50 3 15
C100 HR 7310 0.23 20 23
C200 NGC 6543 15 10 15
C200 HR 6705 0.67 7 23

 
 
\fbox {\fbox{\parbox{15.5cm}{The goals for the improvement of the flux 
reproduc...
 ...$\space 10\%. \\  This needs mainly improved signal processing.\end{itemize}}}}


next up previous contents
Next: 2.3 Absolute and Relative Up: 2 Photometric Accuracies Previous: 2.1 Absolute and Relative

ISOPHOT Calibration Accuracies, Version 2.0, SAI/98-092/Dc