AIPS HELP file for SHADO in 31DEC24
As of Thu Oct 10 7:44:02 2024
SHADO: creates print out of the sensitivity affected by shadowing
INPUTS
INFILE Antenna location file name
in the UVCON format
OUTTEXT Output file name. The file is
at the LATEX or TEXT format
under control of APARM(9)
If number of hour angles
(APARM(5)) > 11 then the
OUTTEXT is not created.
APARM Control information:
1: Min source declin., deg
0 => -30
2: Number of declinations
0 => 12
3: Step at declination, deg
0 => 10
4: Min hour angle, hours
The hour angles are for
the given array center
0 => -4
5: Number of hour angles
0 => 9
see help/explain
6: Step at hour angle, hours
0 => 1
7: Min antenna elevation, deg
8: Max blockage allowed
in fraction of the area
9: Format of the OUTTEXT
0 => LATEX
1 => TEXT
HELP SECTION
SHADO
Task: Estimate the sensitivity loosing of an array because of
shadowing of the array antennas by each other.
The array geometry is given by INFILE. The sensitivity
with taking into account the shadowing is determined as
the ratio of the number of unshadowed antenna to the total
number of antennas. Only antennas with elevation exceeded
the given elevation limit are taking into account.
The antenna is called shadowed if the blockage exceeds
the given limit of blockage.
Adverbs:
INFILE.......Antenna location file name. See format in EXPLAIN
OUTTEXT......Output file name. The file is at the LATEX or TEXT
format under control of APARM(9).
The OUTTEXT is not created if number of hour angles
is .GT. 11.
If LATEX then the OUTTEXT is ready to create the
output as a table in .ps format using LATEX commands
(latex, dvips). You may want to edit the table
capture before command 'latex'
APARM........Control information:
1: Min source declination, degrees 0 => -30
2: Number of declinations, 0 => 12
3: Step at declination, degrees 0 => 10
Each table rows corresponds to new declination
4: Min hour angle, hours 0 => -4
5: Number of hour angles, 0 => 9
The output file is not created if number of
hour angles .GT. 11. The outprint is still
appears on display at this case.
6: Step at hour angle, hours. 0 => 1
The hour angles are given for the given array
center.
7: Min antenna elevation, deg
Only antennas with elevation exceeded
APARM(7) are taking into account.
8: Max blockage allowed in fraction of the area.
The antenna is called shadowed if the blockage
exceeds APARM(8).
9: Format of the OUTTEXT
0 => LATEX
1 => TEXT
EXPLAIN SECTION
SHADO: Task to estimate the sensitivity loosing of an array
because of shadowing of the array antennas by each other.
PROGRAMMER: L. Kogan, NRAO, Socorro.
RELATED PROGRAMS: UVCON
SPECIFYING THE ARRAY CONFIGURATION
The information defining the array configuration is read by
SHADO from an auxiliary input file, supplied by the user. There are
files for all the VLA configurations and the VLBA in the AIPSTARS
directory. These all have the name *_UVCON. This is a free-format
text file. One must list, in the following order:
Line 1: The number of antennas.
Line 2: The site latitude(geodetic), the site longitude, in degrees,
The site height relatively the geoid, in meters.
Line 3: A multiplicative conversion factor specifying how the
antenna coordinates, listed next by the user, can be
converted into units of meters; and a second
multiplicative conversion factor specifying how the listed
antenna diameters can be converted into units of meters.
If the antenna location coordinates are given in nanoseconds,
the conversion factor is 0.299.
The remaining lines specify the antenna location and parameters,
with one line for each antenna. Each line is formatted thus:
Col. 1: The coordinate system: All are right-handed. Units are in
meters, (but see note for Line 3, above).
0 => Equatorial, with X positive towards
Greenwich longitude (and latitude = 0), Y to the
'east', and Z to the North Pole.
Units in meters, but see Line 3 description above.
Warning: VLBA uses opposite direction for Y axis,
so you need to change it if you use it.
1 => Local Horizon, with X positive towards east,
Y positive towards north, Z positive to local zenith.
Units in meters, but see Line 3 description above.
Coordinate origin is at the array center.
2 => Geodetic, with coordinates given by geodetic latitude,
longitude (positive towards west), (both in degrees)
and elevation above the geoid (in meters).
3 => Array Centered Equatorial. The same as '0' but
with X positive to Dec = 0 on local meridian,
Y positive to east, and Z positive towards NCP.
This option is good for VLA
Units in meters, but see Line 3 description above.
Col. 2: Antenna Coordinate X, as defined above.
Col. 3: Antenna Coordinate Y, as defined above.
Col. 4: Antenna Coordinate Z, as defined above.
Col. 5: Antenna diameter (meters, but see note for Line 3, above).
The coordinate system can be mixed up inside of the INFILE
Here is a sample file for a six-element array:
6
30 20
1 1
3 499.8614 -1317.9860 -735.2027 10
1 -801.3750 -124.9699 1182.1318 20
3 -5271.2720 -823.5634 7791.9982 30
3 152.7899 -401.2680 -223.3888 40
3 -6870.8985 -1072.9210 10148.7829 50
3 765.2380 2889.4558 -1108.8724 60
The array center is at latitude 30 degrees and longitude 20 degrees to
west. Conversion factors for both antennas positions and diameters
equal 1, so the relevant values are given in meters. Position of the
second antenna is given in the local RH system with Z as local zenith.
All other antennas' positions are given in a local equatorial
coordinate system. Diameters of the antennas are 10, 20, 30, 40, 50,
and 60 meters.
One must supply the name of the input file via the AIPS
adverb INFILE. Examples:
INFILE='myarea:test.ant' (Unix)
where MYAREA is an environment variable set before
starting AIPS. For example:
percentsetenv MYAREA /mnt/myarea/sim (in csh)
$export MYAREA=/mnt/myarea/sim (in ksh)