Accessing the cal values
Locations of files:
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The cal values are stored in files at ao in the directory: /pkg/rsi/local/libao/phil/data
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The file names (with links to the files) are:
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When users download the ao idl routines, the cal files are included in
the directory ./dat
Terminology:
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h,l high and low cal. There is an attenuator that can be switched in to
go from high cal to low cal.
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D1,D2: there are 2 diodes. 1 diode can feed both polarization or
each diode can feed a separate pol.
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corcal: diode 1 feeds both polA and polB
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cal : this is when dioded 1 feeds polA, diode2
feeds polB
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xcal : cross over. diode 1 feeds polB, diode 2 feeds
polA
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90cal : diode 2 feeds polA and polB. There is a 90 Degree phase shift inserted
in the cal that feeds polA.
File formats:
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The files are ascii files.
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# in column 1 is a comment
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!yyyy daynumber starting in column 1 starts a set of data. The data
that follows is valid on or after yyyy and daynumber.
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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:
frq |
D1h->polA |
D1l->polA |
D1h->polB |
D1l->polB |
D2h->polA |
D2l->polA |
D2h->polB |
D2l->polB |
col0 |
col1 |
col2 |
col3 |
col 4 |
col 5 |
col 6 |
col 7 |
col 8 |
|
hCorcal
hCal |
lCorcal
lCal |
hCorcal
hXCal |
lCorcal
lXCal |
hXCal
h90Cal |
lXCal
l90Cal |
hCal
h90cal |
lCal
l90Cal |
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Alfa data: alfa has a single diode without any of the switching (except
for hi/lo). The column format is:
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freq pix0A pix0b pix1a pix1b ... pix7a pix7B
Idl Routines to access the cal values:
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,
etc...
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corhcalval(b.b1.h,)
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)
hdrs.
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calget1(rcvnum,caltype,freq..)
pass in rcvr number, caltype , and freq. Returns the cal value. This routine
is in the gen/ directory.
C routine to return cal values:
This is the routine that is going to be written one
of these days....
home_~phil