PHT22 (Multi-Filter Photometry with PHT-C Array Detectors)


								   (July 4, 1995)
PHT22 (Multi-Filter Photometry with PHT-C Array Detectors)
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Prior to your visit at IPAC, for each target, please prepare the following parameters for 
entry into the PGA:

==> Common Data for All AOTs (explained on a separate sheet).

==> Parameters for All Filters:
o RASTER:  (Y or N) Y indicates a raster map and N indicates a single pointing 
	   observation.  For a raster map, only filters available to one detector (C100 
           or C200) should be used.  The following parameters are needed for a raster:

	   o  M = number of pointings along each raster leg (the orientation axis) (<=32).
	   o  N = number of raster legs (<=32).
           o  STEP = Step sizes in arcsec in each of the two directions.
	   o  REFERENCE FRAME (Y or N) = Frame of reference for the raster map defined
	      with respect to either the spacecraft Y-axis (Y) or the celestial North (N).
              In the latter case, the raster orientation axis may not be aligned with the 
              spacecraft Y-axis, and the following ORIENTATION ANGLE has to be specified.  
	   o  ORIENTATION ANGLE = The angle of the raster orientation axis with respect
              to the REFERENCE FRAME (N to E, 0-180 deg).  

o CHOPPER: (Y or N) Flag to use chopping (Y) or staring mode (N) for a pointed 
           observation. Note: due to detector drift effect, chopping is not recommended 
           for sources that are brighter than the background, say, by more than a factor 
	   of 2 or 3.  The the following parameters are needed for chopping:

           o CHOPPER MODE:  Rectangular/Triangular/Sawtooth.
           o CHOPPER THROW:  Select one from the on-screen list (cf. ISOPHOT manual).
           o CHOPPER AVOIDANCE ANGLE (Y or N): If yes, specify the starting and ending 
             position angles (N to E).  Note that since the chopping has to be along the
             spacecraft Y-axis, a large angle here may tighten constraints on scheduling 
             this AOT.

o SOURCE TYPE:  P (point source) or E (extended source)

==> Parameters for Each Individual Filter:
o FILTER:  Select one from the on-screen list (cf. ISOPHOT manual).

o SOURCE FLUX DENSITY:  Jy for a point source or MJy/sr for an extended source.

* UNCERTAINTY IN SOURCE FLUX DENSITY:  Jy (point source) or MJy/sr (extended source). 
     Notes: this quantity determines the maximum expected source flux in the quantity
     [(SOURCE_FLUX_DENSITY + UNCERTAINTY_IN_SOURCE_FLUX_DENSITY) + (MAX_BACKGROUND_
     FLUX_DENSITY)], to be used in setting the detector dynamic range.  Values up to 10 
     times the SOURCE FLUX DENSITY are allowed. 

o MAXIMUM BACKGROUND FLUX DENSITY:  In units of MJy/sr. 

* S/N:  Leave 0.0 if you want to enter the INTEGRATION TIME below or enter the requested
     minimum signal-to-noise ratio. 
            
* INTEGRATION TIME: Leave 0.0 if you have requested a minimum S/N ratio or enter the 
     requested minimum integration time.  Notes: (1) For a single pointing observation 
     with or without chopping, this is the on-source integration time expressed in 
     a power of 2 seconds (if you input a non-power of 2, the software will round up your 
     value, e.g., 129 -> 256).  (2) For a raster, this is the integration time per raster
     point.  (3) Because of the detector drift effect, a minimum (on-source) integration 
     of 32 sec is recommended to achieve a 5% accuracy in the relative flux calibration.
     If doing a raster mapping over more or less uniform surface brightness, an exposure
     time per raster point shorter than 32 sec may be used.