Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.naic.edu/~phil/cals/accessingthecalvalues.html
Äàòà èçìåíåíèÿ: Wed Mar 1 19:10:08 2006
Äàòà èíäåêñèðîâàíèÿ: Tue Oct 2 14:36:42 2012
Êîäèðîâêà:
Ïîèñêîâûå ñëîâà: m 101

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:

cal.datR1 - 327 rcvr
cal.datR2 - 430 dome
cal.datR3 - 610 rcvr
cal.datR5 - lbw
cal.datR7 - sbw (sblo)
cal.datR8 - sbh
cal.datR9 - cband (4-6ghz)
cal.datR10 - cband hi (6-8 ghz)
cal.datR11 - xband
cal.datR12 - sband narrow.
cal.datR17 - alfa
cal.datR100 - carriage house
cal.datR147 - 47 Mhz rcvr.

When users download the ao idl routines, the cal files are included in the directory ./dat

Terminology:

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 feeds polB
xcal : cross over. diode 1 feeds polB, diode 2 feeds polA
90cal : diode 2 feeds polA and polB. There is a 90 Degree phase shift inserted in the cal that feeds polA.

File formats:

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:

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

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

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...

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.
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....

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