Alfa cal values measured sep04 on telescope

23jan05

The alfa high cal was measured on the telescope (by desh and ganesh) 30sep04 using sky and absorber. A high order polynomial was fit to the data. This polynomial fit was then sampled every 5 Mhz to generate a table of high cal values covering 1220 to 1520 Mhz. The plots show the cal values versus frequency (.ps) (.pdf)

Fig 1: This has Tcal versus frequency for each pixel plotted separately. Black is polA, red is polB.
Fig 2: The top plot over plots Tcal for polA of all 7 beams. The Bottom plot over plots Tcal for polB of all 7 beams. Color is used to distinguish between the different beams.

For idl processing these cals were installed 22jan05 and backdated to be valid starting 01aug04.

The cal values can be accessed using any of the idl routines that automatically convert to kelvins using the cals (corposonoff, corcalib, etc...). You can get the value of the cal from corhcalval() or calget1(). The cals are stored in ascii format in the file /pkg/rsi/local/libao/phil/data/cal.datR17 (this file is distributed with the ao idl routines in the directory ../data/cal.datR17). The file format is :

frequency pola0 polb0 pola1 polb1 pola2 polb2..... pola6 polb6

processing: x101/mbeam/cals/sep04/doit.pro

home_~phil