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Basic Information on corset
Task: corset
Purpose: Model correlator setups.
Categories: utility
CORSET is a MIRIAD task to model correlator setups. It takes
as input, an observing frequency and IF and then searches
spectral line files for all spectral lines that would be
observable in IF passband. The positions of the lines in
the correlator for the selected correlator settup are plotted.
Key: in
The name of the spectral line file. Up to 5 input files are
permitted. Available files are: $MIRCAT/lovas.3mm, $MIRCAT/lovas.1mm
and $MIRCAT/recom.lis. The default is $MIRCAT/lovas.3mm.
Key: freq
The rest frequency of the line in GHz. The default 110.0 GHz.
Key: iffreq
The intermediate frequency in MHz. The default 150.0 MHz.
This is the frequency in the 90-900 MHz IF at which the line
rest frequency will appear. A negative value indictes that
the line should appear in the lower sideband of the first LO.
Key: vlsr
Vlsr of the source in km/s. The default 0 km/s.
Key: device
The device used for plotting. See the User's Manual for
details on how to specify the PGPLOT device.
Key: log
The output log file. The default is the terminal.
Key: cormode
The mode determines the correlator configuration and number of
spectral windows. The default is mode 8 with the maximum bandwidth.
The following table gives the bandwidth and the number of channels
in each correlator window. The four bandwidths bw1, bw2, bw3, bw4
may be one of 6.25/12.5/25/50/100 MHz. Multiplexing is used for a
bandwidth 50 or 100 MHz, and reduces the number of channels in the
window by a factor 2 or 4 respectively.
Correlator Modes.
-----------------------------------------------------------------
corf1 corf2 corf3 corf4
cormode lsb1 usb1 lsb2 usb2 lsb3 usb3 lsb4 usb4
-----------------------------------------------------------------
1 bw1/1024 - - - - - - -
2 bw1/512 - - bw2/512 - - - -
3 bw1/512 - - bw2/256 - - - bw4/256
4 bw1/256 - - bw2/256 bw3/256 - - bw4/256
5 bw1/512 - 100/32 100/32 - - 100/32 100/32
6 bw1/256 - 100/32 100/32 bw3/256 - 100/32 100/32
7 25/256 - 100/32 100/32 100/32 100/32 100/32 100/32
8 *bw1/128 100/32 100/32 100/32 100/32 100/32 100/32 100/32
-----------------------------------------------------------------
* In cormode=8, bw1 is restricted to 25, 50, or 100 MHz.
These same windows are repeated in both sidebands of the first LO.
There are double the number of channels in auto correlation mode
but there is no sideband separation.
Key: coropt
This keyword identifies the correlator option and is:
0: for crosscorrelation;
1: for autocorrelation;
If this keyword is not present, cross correlation is assumed.
Key: corf
Correlator LO frequencies. Four numbers in range 90 to 900 MHz.
Default=200,400,600,800. Using cormode=8 and corbw=100 gives
the maximum bandwidth contiguous bandwidth from 100 to 900 MHz.
Indicate missing values. e.g. corset cormode=3 corf=200,400,,600
Key: corbw
Correlator filter widths. Up to 4 values depending on the mode.
6.25/12.5/25/50/100 MHz. The default is 100,100,100,100.
The pairs corbw1,3 and corbw2,4 use the same shift rate. 100/50/25
can be paired, but corbw1,3 and corbw2,4 should be the same for
smaller bandwidths. Indicate missing or constant values. e.g.
corset cormode=6 corbw=25,,25
Key: birdie
Number of birdies followed by a list of the birdie frequencies
in MHz. Up to 20 birdies are allowed. The default is 0 birdies.