PROJ

     PROJ is the map projection, projection angles, and margins separated 
     by slashes and an optional image drop flag separated from the rest by
     a bar:

	map proj / ang1;ang2;ang3 / l;b;r;t (margins) | image drop flag

     For all map projections, the lower left and upper right corners of 
     the graphics area should be specified in GAREA.

     The following simple map projections may be specified:

	MER	Mercator
	NPS	North Polar Stereographic
	SPS	South Polar Stereographic
	LCC	Northern Hemisphere Lambert Conic Conformal
	SCC	Southern Hemisphere Lambert Conic Conformal
	CED	Cylindrical Equidistant
	MCD	Modified Cylindrical Equidistant
	NOR	North Orthographic 
	SOR	South Orthographic 
	

     The following full map projections may also be specified:

	MER	(CYL)	Mercator
	CED	(CYL)	Cylindrical Equidistant
	MCD	(CYL)	Modified Cylindrical Equidistant
	STR	(AZM)	Polar Stereographic
	AED	(AZM)	Azimuthal Equidistant
	ORT	(AZM)	Orthographic
	LEA	(AZM)	Lambert equal area
	GNO	(AZM)	Gnomonic
	LCC	(CON)	Northern Hemisphere Lambert Conic Conformal
	SCC	(CON)	Southern Hemisphere Lambert Conic Conformal


     In addition for full map projections, three angles MUST be specified
     in PROJ.  The angles have the following meanings for the different
     projection classes:

	CYL	angle1 -- latitude of origin on the projection cylinder
			  0 = Equator
 		angle2 -- longitude of origin on the projection cylinder
			  0 = Greenwich meridian
 		angle3 -- angle to skew the projection by rotation of
			  the cylindrical surface of projection about
			  the line from the Earth's center passing
			  through the origin point. This results in
			  curved latitude and longitude lines.

			  If angle3 is greater than 360 or less than -360
			  degrees, then the rectangular Cartesian coordinate
			  system on the projection plane is rotated
			  +/- |angle3|-360 degrees. This results in
			  latitude and longitude lines that are skewed
			  with respect to the edge of the map.  This option
                          is only valid when specifying a map projection and
                          is not available for grid projections.

			  The difference between |angle3| < 360 and
			  |angle3| > 360 is that, in the former case,
			  the rotation is applied to the developable
			  cylindrical surface before projection and
			  subsequent development; while, in the latter
			  case, the rotation is applied to the Cartesian
			  coordinate system in the plane after development.
			  Development here refers to the mathematical
			  flattening of the surface of projection into a
			  planar surface.

	    Exception:

	    MCD	    angle1 -- scaling factor for latitude
			      0 = default scaling (1/cos(avglat))
 		    angle2 -- longitude of origin (center longitude)
 		    angle3 -- not used
 

	AZM	angle1 -- latitude of the projection's point of tangency
 		angle2 -- longitude of the projection's point of tangency
 		angle3 -- angle to skew the projection by rotation about
			  the line from the Earth's center passing
			  through the point of tangency

	CON	angle1 -- standard latitude 1
 		angle2 -- polon is the central longitude
 		angle3 -- standard latitude 2

     The angles for the full map projection types are given as three numbers 
     separated with semicolons.  Note that THREE angles must be entered even 
     if some angles are not used.

     Note that transverse projections may be obtained using a cylindrical
     projection with the first angle set to either 90 or -90.  The second
     angle is the longitude at which the cylinder axis intersects the
     equator.  This will be the transformed location of the "south" pole
     when the first angle is 90 or the "north" pole when the first angle
     is -90.  For example, if angle1 = 90 and angle2 = 0, the axis of the
     cylinder of projection is perpendicular to the earth's axis and enters
     the earth at 0N 0E and emerges at 0N 180E.  The great circle formed
     by 90E and 90W becomes the "equator" on the cylinder.  This cylinder
     is ideal for a transverse cylindrical projection of locations on the
     continent of North America.
 
     Satellite and radar projections are available:

	SAT	specifies remapped or nonremapped satellite
 		projections.

	RAD	specifies the radar projection.

     Currently, the McIDAS area format is supported for satellite and
     radar images. NIDS radar images from WSI may also be displayed.
    
     The image drop flag may be specified as a D or an ND, and is valid
     for SAT and RAD only. A value of D causes the image to be dropped
     before any additional graphics are drawn. Conversely, a value of ND
     does not drop the image. When the image drop flag is undefined, the
     image is dropped when CLEAR is set to YES, and is not dropped when
     CLEAR is set to NO.

     If the projection is DEF or is blank, a default projection will be
     obtained from the geographic table for the specified GAREA.  If no
     default projection has been defined for the specified GAREA and the
     projection is DEF, the current map projection will be used.

     In the grid programs the following graph projections are also
     available:
 
	LIN	linear x, linear y
	LOG	linear x, logarithmic y
	KAP	linear x, y ** KAPPA
	POL	polar coordinates ( R, THETA )
 
     Margins may be input as four numbers separated with semicolons.  The
     four numbers represent the left, bottom, right, and top margin
     sizes in character widths.  If no margins are specified, the default
     will be (0,3,0,0) in map mode and (6,4,4,1) in graph mode.  If the
     input for the margins is NM, all four margins will be set to 0.