PIA data reduction for P03/P22
------------------------------
(details about the individual correction/processing
 algorithms can be found in:
 http://www.iso.vilspa.esa.es/manuals/PHT/pia/um/processing.html)

ERD level:
 * Non-linearity correction
    --> Correction
        --> non-linearity

   (Nonlinearities in the Cold Read-out Electronics output voltages
    and also de-biasing effects are mainly affecting the long-wave
    detectors with low bias P3, C100 and C200 and result in
    ramp Nonlinearities.)

 * Read-out deglitching
    --> Test processing
        --> Test deglitching (single or 2 Threshold method)
            --> Accept & Quit
    --> Correction
        --> Read-out simple deglitching or 2 Threshold deglitching

    (Cosmic particles hit the detector pixels with such energy, that
     the voltage ramps are seriously disturbed: local 'jumps' between
     2 read-outs, or even 3 read-outs, and an immediate relaxation.
     the information redundancy on voltage differences between
     read-outs allows us to pick out those anomalous jumps and to
     correct the ramps affected. The 2 Threshold deglitching is
     more efficient.)

 * Saturated Ramps
   --> Correction
        --> Change Saturation Params
   (Integration of a ramp above the saturation limit (~ 1.2 V)
    is not possible. An automatic recognition for all cases has
    been introduced in PIA. Changing the Parameters is usually
    not necessary.)

 * Raster point ID correction for tracked SSO observations
   --> Correction
        --> Set RPID -> [1,1]
   (PIA considers now the measurement as tracked observation.
    PIA does not automatically recognize the tracking mode, since
    it is performed in the same way as rasters.)

 * Ramp fitting
   --> Process Measurement
       --> Fit ramps
           --> 1st order Pol.
           or 
           --> use subdivided ramps
           (A better time resolution on the signal level can
            be reached by using the method of ramp sub-division.
            The user can define a pseudo-ramp with fewer
            read-outs than the original one. An important reason
            for ramp sub-division is for some cases with a very
            low number of ramps per chopper plateau.)

SRD level:

 * Reset interval correction
   --> Correction
       --> Reset interval correction
   (There exists a signal dependance on the reset interval used for
    read-outs sampling. The effect is detector and CRE dependent and
    leads to signal differences if the same flux is measured using
    different ramp integration times.)

 * Signal Deglitching
   --> Correction
       --> Deglitching
           --> Customize: 2 Iterations (or more), Use max/min clipping
   --> Correction
       --> Deglitching
           --> Perform it
   (There is also the posibility to do the deglitching manually:
    --> Test processing
        --> discard area graphically)

 * Dark current subtraction
   --> Correction
       --> Dark current subtr. (orbital dep.)
           --> Customize: Interpolate one value per data point, ok
   --> Correction
       --> Dark current subtr. (orbital dep.)
           --> Perform it
           
   (Dark currents exist for every detector pixel, binned
    reflecting the dependence of the dark currents on the orbital
    position. For several detectors (mainly Ge:Ga) the cosmic hit
    radiation plays a dominant role and changes the dark currents
    with orbit position.)

 * Signal derivation
   --> Process
       --> with drift handling: Stability recognition, ok

   (More sophisticated methods to derive the final signal are
    available under --> Process
                        --> with drift handling: Drift modelling, ok)


SCP level:

 * Vignetting correction
    --> Correction
       --> 
   (The ISOPHOT detector pixels can be telescope vignetted depending
    on the aperture used and on the chopper throw. Only implemented
    for C100 and C200 detectors.)


 * Determination of actual Response (Measurement title says: staring FCS)
   --> Process
       --> Responsivity calculation
  
 * Power calibration of your on-source measurement
   --> Process
       --> Power calibration
         --> Actual Response
         or 
         --> Default Response (orbit dep.): Customize, Perform it

AAP level:

 * Background subtraction
   (should be done preferably on SCP level to avoid color correction
    problems)
   --> Process
       --> Background Subtraction 
           --> another measurement
   (the background measurement has to be in the buffer, reduced
    in the same way.)

 * Color Correction
   Check the lookup tables on the main PIA panel:
    --> Files
        --> Calibration Info
            --> Colour Correction
 
   Divide your obtained (source-background)-flux [Jy] by the
   color correction factor.