HAZI

HAZI generates the (u,v) tracks for a hypothetical VLB experiment. A plot of the tracks can be produced on any of the graphics devices supported by PGPLOT. A listing of the azimuth, zenith angle and hour-angle of the source at each telescope and of the IHA of the source on each baseline can be made.

Example

hazi <<EOD
  srcfile = "/usr/local/vlb/sources.cat"
  stafile = "/usr/local/vlb/stations.cat"
  plotfile = hazi_example.ps/ps
  npxy = 2,1
  listfile = hazi.lis
  source = "0108+388"
  freq = 5010
  dots
  dt = 0.1	! dots every 6 minutes
  noblid noticks ! suppress baseline numbers and tick marks
  stations = "VLBA_SC", "VLBA_HN", "VLBA_NL", "VLBA_FD", "VLBA_LA", "VLBA_PT",
             "VLBA_KP", "VLBA_BR", "VLBA_BR", "VLBA_MK"

  /
  stations = "ONSALA", "BONN", "CRIMEA", "JODRELL", "WSRT", "BOLOGNA",
             "NOTO", "HART", "HSTK", "NRAO", "VLBA_NL", "VLBA_LA", "VLA",
             "OVRO", "HCRK"
  /
  exit
  /
EOD
This example produces a PostScript file hazi_example.ps with two panels.

Parameters

At least two STATION names and one SOURCE name (or RA and DEC) must be specified; the other parameters are optional. The parameter names can be abbreviated (minimum match). End the list of parameters with a slash (/) or end-of-file (control-Z in VMS, control-D in Unix).
PLOTFILE = "device/type"
Plot device specification in the format required by PGPLOT. Default is no plot.

NPXY = nx, ny
Subdivide pgplot page into nx by ny panels, with one uv-plot per panel. Default is 1,1.

LISTFILE = "filename"
File to receive listing. Default is HAZI.LST. Use LISTFILE="*NOLIST*" to suppress this listing. On VMS systems LISTFILE="SYS$OUTPUT" outputs to the terminal.

STATIONS = "name","name",...
A list of station (antenna) names from the catalog [up to 20].

SOURCES = "name","name",...
A list of source names from the catalog; if only one name is given, the coordinates can be supplied in RA and DEC insteadof the catalog [up to 10].

RA = hh:mm:ss.sss
DEC = dd:mm:ss.ss
If there is only one source, the apparent coordinates can be specified in RA and DEC. If RA and DEC are omitted, or if there is more than one source, the coordinates are found by searching the source catalog.

STAFILE = "file"
The file name of the station catalog. The default is "VLB_STATIONS" which can be a VMS logical name.

SRCFILE = "file"
The file name of the source catalog. The default is "VLB_SOURCES" which can be a VMS logical name. The source catalog is not used if RA and DEC are supplied.

GST = start, stop
Start and stop times in hours, Greenwich Sidereal Time: e.g., GST=22.0,06.5 gives a run of 8.5 hours. If GST is not specified, tracks are calculated for a full 24 hours. In any case the tracks are only drawn where the source is visible from both telescopes.

NUP = number
If NUP is specified, tracks are only drawn for periods when at least NUP telescopes can see the source (default: NUP=2).

FREQ = number
Specify the frequency of observation in MHz. If the frequency is not specified, the graph will be labeled in kilometers instead of wavelengths.

DATE = yy:mm:dd
Date of propsed observation, e.g., DATE=79:5:12 (default: today's date),

PRINT = 1 or 2
If PRINT=1 is specified, a table of HA, ZA, AZ for each telescope will be produced; if PRINT=2 is specified, a table of IHA for each baseline will be produced; if PRINT is specified with no value, both tables will be produced.

TITLE = "text"
Title to be printed at top center of plot, up to 32 characters long.

NOBLID
Suppress baseline labels on plot.

NOINVERT
Suppress plot of conjugate tracks.

NOTICKS
Suppress the tick marks at 1-hr intervals of IHA.

DOTS
Plot dots every DT hours, instead of continuous lines.

DT = number
Sets the resolution (in hours), default=min=0.1; this is the time interval between calculation points, and the interval between dots when DOTS is specified.

UVMAX = number
This can be used to force the scaling of the plot: the region encompassed by the frame of the plot will run from -UVMAX to +UVMAX in both dimensions. If UVMAX is less than the actual maximum of u or v, some of the tracks will not appear on the plot. The units are millions of wavelengths, or kilometers if FREQ is not specified.

LINEWIDTH = n
Use this parameter to draw heavier lines. The default line-width is 1 (0.005 in); values up to 21 are allowed.

FONT = n
Specifies the character font to be used for labelling the graph. The default (1) gives a simple font; other options are 2 (roman), 3 (italic), and 4 (script).

STCODE
Use station codes from the stations catalog for the plot legend instead of full station names.

EXIT
The program restarts until EXIT is specified. It is needed to allow multiple plots in one file.

Catalogs

HAZI reads the standard KEYIN-formatted catalogs used by SCHED, UPTIME, PRECESS, etc. See the SCHED help file for more information.

History

Version 1.0: 1979 May 10 - new program (T. J. Pearson).
Version 1.1: 1979 Oct 15.
Version 1.2: 1979 Nov 6 - more than 1 source.
Version 1.3: 1980 Mar 14 - ask questions.
Version 1.4: 1980 Mar 25 - options NOTICKS, DOTS, GST.
Version 1.5: 1980 Jun 30 - increase to 15 stations.
Version 1.6: 1980 Nov 23 - cure bug in tick marks.
Version 1.7: 1981 Jun 11 - Fortran-77 standard.
Version 1.8: 1982 Jun 9 - new graphics devices.
Version 2.0: 1982 Dec 23 - correct bug for invisible sources or sources circumpolar about S pole; add parameter NUP; compare names in upper case; scale in km if frequency not given.
Version 2.1: 1984 Sep 25 - add FONT and LINEWIDTH parameters to match UVPLOT (TJP).
Version 3.0: 1987 Sep 1 - use parameter input for file names; remove antiquated GRPCKG calls; increase to 20 stations (TJP).
Version 3.1: 1988 Apr 5 - changes for Convex (TJP).
Version 3.2: 1991 Feb 1 - new catalog format; correct labelling bugs (TJP).
Version 3.3: 1993 Jan 4 - avoid crash on zero-length baseline (TJP).
Version 4.0: 1993 Nov 23 - new parameters NPXY, STCODE, EXIT; use TITLE; "*NOLIST*" option (AKT).
Version 4.1: 1994 Nov 17 - 12-char source names, aliases (TJP).


Tim Pearson, California Institute of Technology
tjp·astro.caltech.edu