Accessing the cal values
Locations of files:
The cal values are stored in files at ao in the directory: /pkg/rsi/local/libao/phil/data
The file names (with links to the files) are:
When users download the ao idl routines, the cal files are included in
the directory ./dat
h,l high and low cal. There is an attenuator that can be switched in to
go from high cal to low cal.
D1,D2: there are 2 diodes. 1 diode can feed both polarization or
each diode can feed a separate pol.
corcal: diode 1 feeds both polA and polB
cal : this is when dioded 1 feeds polA, diode2
xcal : cross over. diode 1 feeds polB, diode 2 feeds
90cal : diode 2 feeds polA and polB. There is a 90 Degree phase shift inserted
in the cal that feeds polA.
The files are ascii files.
# in column 1 is a comment
!yyyy daynumber starting in column 1 starts a set of data. The data
that follows is valid on or after yyyy and daynumber.
freqMhz followed by 8 columns of cal values in Kelvins. Each column has
the value for 1 of the diodes feeding polA or polB. The mapping of these
columns to cal names are:
Alfa data: alfa has a single diode without any of the switching (except
for hi/lo). The column format is:
freq pix0A pix0b pix1a pix1b ... pix7a pix7B
There are idl routines that will read in the cal files
and interpolate to the requested frequency. One routine uses a spectral
line header (interim correlator or was/wapp) to figure out the cal that
was used. A second routine lets the user input the cal type, frequency,
Idl Routines to access the cal values:
pass in a header, it returns the cal value. The routine is located in the
Cor2 directory and is accessible using the interim correlator or was (wapp)
pass in rcvr number, caltype , and freq. Returns the cal value. This routine
is in the gen/ directory.
This is the routine that is going to be written one
of these days....
C routine to return cal values: