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The Parameters Files

  The ARCON software has made it easy for you to observe by providing a single word for data-collection: observe. However, this ease has not come at the cost of flexibility; instead, all the options have been buried in the parameter files. There are four of these parameter files which must be properly set, but which you will likely leave alone throughout the course of your run:

detpars
This parameter file controls the fundamentals of how the CCD detectors are read. All items in this parameter file are crucial for correct operation of the CCDs.

instrpars
This is the instrument parameter file, and it is mostly useful for specifying whether or not you want to be asked for filter and focus values for each exposure.

obspars
This is the parameter file that is used by the astronomer to tailor the observe command to his/her liking, and in particular to specify how the root name of the exposures are constructed.

telpars
This parameter file is used only to specify the protocol needed to communicate with the telescope computer in order to allow proper transfer of header information (time, telescope position and particulars) to the ARCON software.

These parameter files can each be listed using the lpar command, e.g., lpar detpars

and may be edited using the parameter editor epar, e.g., epar detpars

However, the change will not take effect (for detpars) unless you then run setdet.

detpars

The detector parameter file detpars allows the astronomer to specify how the chip is to be formatted, which amplifiers are in use, and so on. It also contains additional ``readonly" information which is inserted into the headers, such as the pixel size in microns. There are two gain settings for Mini-Mosaic. The default gain (1.4 e/ADU) does an excellent job of mapping the full linearity range (70,000 e) to the 16-bit range of the A/D converter (65,000). The second gain setting gives 0.9 e/ADU and nominally slightly lower readnoise. We recommend that you leave detpars alone. If you do choose to change anything in detpars it will not take effect until you then run setdet, which regenerates the waveforms which run the CCDs. The parameters are shown in Figure 3.

Digression: The Power of ccdinfo

  Once your detpars is setup, you can verify all of these important parameters by simply typing the command

ccdinfo

You will get a response that resembles that of Figure 4.

instrpars

  this parameter is currently useful at WIYN only for turning on or off the queries for filter and focus. Eventually this will allow you to specify a base and reference temperature and have the focus adjusted for changing temperature. The default listing is shown in Figure 5.

obspars

  The parameter file obspars allows the astronomer to specify details of how the images will be named and contains other information that will be passed on for the headers. A sample obspars can be seen in Figure 6 .

telpars

The final relevant parameter file used by the ARCON software is telpars. It serves primarily as the memory of the answers you gave during the most recent focus frame. The telescope name needs to be right, and there are a few ``readonly parameters" which are there to provide information for the headers. The parameters are shown in Figure 7. .


Next: Dealing with the Data
Previous: Observing Overview: Taking the Data
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Thu Aug 24 09:59:47 MST 2000