Basic Information on uvhat

Task: uvhat
Purpose: Convert Hat Creek uv format into MIRIAD uv format
Categories: data transfer

UVHAT is a MIRIAD task which converts a file from RALINT UV format 
into MIRIAD UV format.
On VMS it automatically detects so called ``oldhat'' and ``newhat''
formatted RALINT files.
On SUN Unix the ``oldhat'' data can only be converted with UVHAT.
On SUN Unix the ``newhat'' data can only be converted with HCCONV.

Key: in
The input file name. No default.
Visibility data may be accessed either directly by giving
the filename, or indirectly via an index file which is
identified by name.INC. The index file can also select data
by time range and antennas, and the data can be scaled by
parameters in the index file. The index file can be used to
directly convert RALINT uvdata sets into a MIRIAD uv file.
The structure of the index file is as follows: 

filename.ext    (name of the data file to include)
first, last     (selects day.ut range)
first, last     (selects day.ut range; up to 20 time ranges)
ANT=num         (select antennas, e.g. 123 for all three)
SCA=s1,s2,s3    (scales the data for baselines 12, 23, 31)
WEI=w1,w2,w3    (weights - not used in UVHAT)
DPH=p1,p2,p3    (phase correction added to data for baselines 12,23,31)
                [units: radians]
next <filename.ext>
etc.

The scale factors can be used to convert the visibility data to Jy
for mapping. This is normally done by the calibration. The data for
the preceeding filename is multipled by sca(i)*expi(dph(i)) for
baselines i=1,2,3.

Bad channels can be flagged using the following two parameters:

CHN= number of ranges followed by list up to 10 pairs of numbers
to specify ranges of GOOD channels.

BAD= number of ranges of bad channels followed by list of up to
      10 pairs of numbers to specify ranges of BAD channels.

e.g.    CHN=2,1,64,129,256
        BAD=3,32,33,135,137,19,191
uses channels 1 tho 64 and 129 thro 256, and flags channels (32,33)
(135,137), and (191,193). Channels .gt.256 are flagged BAD.

The initial default is CHN=1,1,512  i.e. no bad channels.
The channel selection is not reset for each file and need only be
reset if channel selection changes.

Comment lines must start with ``!''.

Key: out
The output dataset name (looks like 1-30 alphas, ends up as a
subdirectory of the current default directory.

Key: logrange
The beginning and end Hat Creek Log number, to be included in
the output. Default is all data.