Last changed 29 Sept 2003 by jeffh @ naic.edu

WAPP Spectral Line Observing Notes

Here are some notes describing how to use the WAPP for spectral line observing. Basically the setup is like the Interim correlator.

• Start CIMA
• Set the project id
• Choose a receiver
• Point at a source and set velocity
• Choose Correlator Control
• Choose WAPP
• Set the correlator configuration
• Press Apply Current Setup
• Adjust power
• Choose Spectra Line Observing
• Choose Standard On, Standard Off or Double Position Switching
• Observe

Observing Notes:

• Currently, the only supported observing modes are Standard On, Standard ON/OFF, Double Position Switching
• A FITS file can hold 4096 spectra. A new file will be created anytime it detects there isnt enough room for a new scan. The only the version number increments
• A FITS filename is of the form /share/wapp11/a9999_wapp1_0009.fits Thats /share/wapp[0-4]1/project_machname_index.fits.
• For now, the number of spectral points is always the maximum for the mode you selected in spite of what the GUI says.
• Right now, the Integration time is always 1 second, in spite of what it says on the GUI.

Debugging tools:

I have created several debugging tools that can be used to verify what got written to the FITS file. These are in the directory /share/wappsrc/fits:

• asciifits [ -all ] [ -header ] filename, the -all switch dumps all data. Without it, the last scan is dumped. The -header switch causes the header values to be dumped instead of spectra.
• /share/wappsrc/utility/showplot can plot the spectra as provided by asciifits.
• shrink_fits, removes remaining empty table entries and shrinks the FITS file to its final size. A "shrunk" FITS file cannot be written to by WAPP.
• test_fits, creates FITS files for testing. If test_fits gets a syntax error then the there is a big problem in the FITS writing software.