IARC Acqisition Modes Explained.

1. Supported Modes

   SINGLE - classic fowler sample mode.
   DOUBLE - classic fowler sample-pedestal mode.
   RAMP   - A sample up the ramp implemenation.
   RAW    - save all array readouts.

terms

   RESET - A reset readout - the array is readout (pixel-by-pixel) while resetting the array.
           The array readout time is identical to the samples readouts.
           The data is not sampled.
   SAM   - A sample readout. This readout is a pixel-by-pixel readout. The data is sampled.
   PED   - a sample readout, but referred to as a pedestal data set.
   ITIME_NDR   - a sample readout. During intergration the array is continuous readout.
           The ITIME_NDR are readout that are sample, but ignore in order to set the
           SAM, PED readout to the correct integration times.

   NRD   - In fowler method, the SAM and PED readouts can be repeated in succession.
           Taking multiple readouts then later averaging them reduces the noise.

SINGLE

    The array is reset. A serial of samples * ndr are added together to form 1 coadd frame.
    The coadds are summed for the final FITS images.

    ( RESET [ITIME_NDR] [SAM * NDR] ) * coadd.

    TBD: The integration time is mesured from the reset to the midpoint of [SAM*NDR].

    IARC parameters:
       -m mode  = set to SINGLE
       -r ndr   = NDR value.
       -c coadd = COADD value.
       --itime_ndrs N = ITIME_NDR value.

     ic_readout: n_image_count = ((iarc_setup.n_ndr_count) + iarc_setup.itime_ndrs)*iarc_setup.n_coadd_count;
   data_handler: coadds all the images.
                 Data stored in int array[].


DOUBLE

    The array is reset.
    A dummy readout is taken (1st readout after a reset is noisely).
    PED samples are summed.  (NDR are supported).
    After the integration time, SAM samples are summed. (NDR are supported).
    A coadd is SAM-PED.
    The coadds are summed to produce a FITS 1 image.

    ( RESET, [DUMMY_READ], [PED * NDR], [ITIME_NDR], [SAM * NDR] ) * coadd.

    The integration is the time between SAM and it corresponding PED frame.
   
    IARC parameters:
       -m mode  = set to DOUBLE
       -r ndr   = NDR value.
       -c coadd = COADD value.
       --itime_ndrs N = ITIME_NDR value.

     ic_readout: iarc_setup.n_img_count = ((iarc_setup.n_ndr_count * 2) + iarc_setup.itime_ndrs)*iarc_setup.n_coadd_count + iarc_setup.n_coadd_count;
   data_handler: image = sumof( ped_ndr , -sam_ndr ), ignore 1st readout of coadd
                 Data stored in int array[].

RAMP

     The array is reset.
     A series of readout are used to calculated the slope.
     The slope values are output as a FITS images (using floats).

    IARC parameters:
       -m mode  = set to RAMP
       -r ndr   = NDR value.                 // Set to 0
       --itime_ndrs N = ITIME_NDR value.     // Use itime_ndrs to setup number of images

     ic_readout: n_img_count = (iarc_setup.n_ndr_count) + iarc_setup.itime_ndrs;
   data_handler: add readout used to determine slope.
                 Data stored in float array[].

   ASK:
      maybe,  n_img_count = itime_ndrs?
      Is coadd parameter truly ignored?
      How about returning: slope, intercept, and estimated 'Image' all as floats.

RAW

   The array is reset.
   A series of individual readouts are readout and saved.
   Number of FITS producted are ITIME_NDR.

      RESET [ITIME_NDR]

   The integration time of each frame is N*ITIME_NDR(sec)

    IARC parameters:
       -m mode  = set to RAW
       -r ndr   = NDR value (set this to 0)          // set to 0
       -c coadd = COADD value.                       // set to 1
       --itime_ndrs N = number image to readout.      // use this to set the number of RAW images.

     ic_readout: n_img_count = (iarc_setup.n_ndr_count + iarc_setup.itime_ndrs) * iarc_setup.n_coadd_count;
   data_handler: add readout used to determine slope.
                 Data stored in short array[].

   ASK:
      Is coadd parameter truly ignored?  Or is coadds a series of RAW?