Select the P22/P37/P38/P39 ERD files and read them into the PIA buffer.
The C200 data files have P2ER prefix. In the case of sparse
map data chain of P37/P38/P39, the FCS measurements are contained in P37
and P39 only, and one should consider reading all of them into the PIA
[ ] (Top Window) Files -> Files Manager
[ ] Select File Type: ERD and Detectors: C200.
[ ] The ERD file name(s) should appear in the "Files" subwindow. If not,
you can click on one of the subdirectory names shown in the
"Subdirectories" subwindow to see if you can navigate to the desired file.
Once you have located the correct file in the "Files" subwindow, click on
the file name.
[ ] Click on "Read File" button to read the selected file into the PIA buffer.
[ ] Option: Click on "Show Header" button to view or to print the ERD FITS
Normally, one reduces the FCS measurement(s) first then the astronomical data. In the case of P37/38/39, this means that one processes both of the two FCS measurements first. Note that the steps from ERD to SCP are the same regardless of whether the measurement being processed is FCS or astronomical.
Select an ERD measurement for processing.
[ ] (Top Window) Buffers -> Buffers Manager
[ ] Select Data Type: ERD and Detectors: C200. All the measurements in the
selected category should show up in the "measurement" window. For P22,
there is only one FCS measurement. There should be two FCS measurements
(one from P37 and the other from P39). Usually, 2 or more positions are
observed using one or more filters. Select the measurement by clicking
[ ] Click on the "Plot & Reduce Data" button to bring up the PIA ERD window.
[ ] Option: click on the "Show..." button in the Buffers Manager window to
view FITS header, Compact Status or even the data values themselves.
Hint: it may be a good idea to process all the measurements in the same AOT to the SCP level before proceeding to the SPD level.
If this is a FCS measurement:
[ ] (SCP Window) Correction -> Straylight subtraction (This correction
is still uncertain, at a level of up to a few percent for C200)
[ ] (SCP Window) Process -> Responsivity Calculation
Click on the "ACCEPT" button for the average responsivity value from FCS1.
If this is an astronomical measurement:
[ ] (SCP Window) Process -> Power Calibration
If this is a P22 measurement, select either default responsivity or
the actual FCS for power calibration; if this is a P37 or P38 or P39,
one can select to use the last Responsivity calculated from a FCS
measurement (Actual Responses), or to use the average (Average Responses)
or a linear interpolation in time between the two FCS measurements
(Interpolate Responses). In the last two cases, do the following steps:
Select the FCS
measurements on the pop up window and then click the "Ok"
button. When the PIA Response Menu window appears for each FCS
measurements, then click on the "ACCEPT" button to choose the average
responsivity value from FCS1. This converts V/s to watts and pops up
an AAP window.
Hint: in the case of P37/38/39, by concatenating the SRD or SCP results
of all the measurements (including the 2 FCS measurements) in the same
AOT, one may better judge which of the following is a better way to do
flux calibration: interpolation, averaging or simply using only one of
the FCS measurements.
Hint: If this displayed measurement is the on-source measurement, then do a background subtraction as follows: [before doing so, you may also want to examine the 4 pixel levels of the off-source measurement as outlined above]
[ ] (AAP Window) Process ->
Background Subtraction (another measurement)
[ ] Select the off-source measurement from the pop-up window.
The subtracted AAP result is stored in the PIA butter.
[ ] Option: Save the sky-subtracted result into a disk file of PIA internal
format by using the "Save... (Internal Save File)" button on the Buffer