SNMAP plots sounding data on a map.

INPUT PARAMETERS
 
    AREA      Data area
    GAREA     Graphics area
    SATFIL    Satellite image filename(s)
    RADFIL    Radar image filename(s)
    IMCBAR    Color/ornt/anch/x;y/ln;wd/freq
    SNPARM    Sounding parameter list
    DATTIM    Date/time
    LEVELS    Vertical levels
    VCOORD    Vertical coordinate type
    SNFILE    Sounding data file
    COLORS    Color list
    MAP       Map color/dash/width/filter flag
    MSCALE    fgc;bgc;mask/units/lat;hide/values/anch/x;y/ln;wd/freq|text_info|t
    LATLON    Line color/dash/width/freq/inc/label/format
    TITLE     Title color/line/title
    CLEAR     Clear screen flag
    PANEL     Panel loc/color/dash/width/regn
    DEVICE    Device|name|x size;y size|color type
    PROJ      Map projection/angles/margins|drop flag
    FILTER    Filter data factor
    TEXT      Size/fnt/wdth/brdr/N-rot/just/hw flg
    LUTFIL    Enhancement lookup table filename
    STNPLT    Txtc/txt attr|marker attr|stnfil#col
 
 

PROGRAM DESCRIPTION
 
    SNMAP plots sounding data parameters at station locations
    on a map.  Any level or station parameter that can be
    computed can be displayed.  Data may be plotted in any valid
    GEMPAK projection and may be overlaid on images.

    A list of times may be given in DATTIM allowing animation of
    sounding plots.

    The order of the input parameters determines their location
    on the plot.  Parameters are separated by semicolons.  A
    position may be skipped by entering two consecutive
    semicolons or entering parameter SPAC or BLNK.  A parameter
    will be plotted centered at the station if it is the first
    parameter in the list. If no parameter is to be displayed
    centered on the station location, a semicolon must appear
    before the first parameter, or the first parameter must be
    either SPAC or BLNK.  The following chart shows the placement
    of the data around the station.  The number indicates the
    position of the parameter in the SNPARM list:

				8
			2	10	4
			3	1	5
			6	11	7
				9

    Note that wind symbols and markers are always plotted at the
    center.

    Station data will be filtered; i.e., overlapping stations
    will not be plotted, if FILTER is set to YES.  FILTER may
    also be entered as a number greater than or equal to zero.
    FILTER = NO has the same effect as FILTER = 0.  FILTER = 1
    has the same effect as FILTER = YES.  Values less than 1
    allow more crowding of stations, values exceeding 1 less
    crowding.  If a parameter is BLNK, the filter will not allocate
    any space for that parameter.  The parameter SPAC may be used
    to reserve the space with the FILTER option so that later calls
    will plot the same stations after filtering, provided that the
    same number of parameters is specified.

    If certain stations are not to be removed by the filter, these
    stations are listed first following an @.  The area over which
    filtering is to occur is specified after a slash.  For example,

			AREA   = @iad;hts;rap/us
			FILTER = YES

    will display a filtered array of stations over the area
    corresponding to US, but IAD, HTS and RAP will be shown
    regardless of the filtering.

    Either wind barbs or wind arrows can be plotted, by
    specifying a wind symbol parameter name in the list of
    parameters for SNPARM.  The wind barb or arrow is plotted
    at the station location according to the type specification,
    which is entered as described in the SNPARM documentation.

    Conditions can be specified for the parameters.  The
    conditions are documented in the SNPARM documentation.  Note
    that individual parameters can be scaled using these
    conditional functions.  For example, TMPC*10 will plot
    temperature multiplied by 10.

 
EXAMPLES
 
    1.  Plot a polar stereographic map of stations in the Eastern
	United States at 850 mb for all times in the data file.
	Plot a standard station model for each location. The upper
	air data to plot include: 1) wind barbs in knots;
	2) temperature in Celsius; 3) coded height; 4) dewpoint
	depression in Celsius; and 5) station ID.  The data are
	plotted using the specified color list.

	AREA	 =  east-
	GAREA	 =  east
	SATFIL	 =
	RADFIL	 =
	IMCBAR   =
	SNPARM	 =  brbk:1:2:112;tmpc;;stdz;;dpdc;stid
	DATTIM	 =  all
	LEVELS	 =  850
	VCOORD	 =  pres
	SNFILE	 =  $GEMPAK/data/hrcbob.snd
	COLORS	 =  6;2;5;3;18
	MAP	 =  1
	LATLON	 =  2/10/1/1/10;10
	TITLE	 =  1
	CLEAR	 =  yes
	PANEL	 =  0
	DEVICE	 =  xw
	PROJ	 =  nps
	FILTER	 =  no
	TEXT	 =  1
	LUTFIL   =
	STNPLT   =

    2.  Plot the temperature and height at 500 mb and the lifted
	index for all times in the data file.  The data are plotted
	at the stations where the temperature is less than -8
	degrees Celsius.  The lifted index is multiplied by 10
	before being plotted.

	AREA	 =  us-
	GAREA	 =  us
	SATFIL	 =
	RADFIL	 =
	IMCBAR   =
	SNPARM	 =  mark:2;;tmpc<-8;;hght;;;;;lift*10
	DATTIM	 =  all
	LEVELS	 =  500
	VCOORD	 =  pres
	SNFILE	 =  $GEMPAK/data/hrcbob.snd
	COLORS	 =  2;5;3
	MAP	 =  1
	LATLON	 =  2/10/1/1/10;10
	TITLE	 =  1
	CLEAR	 =  yes
	PANEL	 =  0
	DEVICE	 =  xw
	PROJ	 =  mer
	FILTER	 =  0
	TEXT	 =  .75
	LUTFIL   =
	STNPLT   =

ERROR MESSAGES
 
    [SNMAP  +1]     Parameter ... cannot be computed.
    [SNMAP  -1]     Fatal error initializing TAE.
    [SNMAP  -2]     Fatal error reading TAE parameters.
    [SNMAP  -3]     Fatal error initializing GEMPLT.
    [SNMAP  -4]     Invalid levels or vertical coordinate have been input.
    [SNMAP  -5]     A range of levels is invalid in SNMAP.
    [SNMAP  -6]     Winds cannot be computed.