Simple MapServer file for uv (wind) raster data.

mapserver-wind.map

# Wind barbs for uv raster data.
#
# The symbol "windbarb" has two barbs. The symbol should be split in multiple symbols and
# the raster layer should have multiple CLASS with EXPRESSION: each CLASS will use the right
# number of barbs.
#
# Note: the uv values of the input file `out.tiff` are between 0 and 1.
MAP
    IMAGETYPE PNG
    OUTPUTFORMAT
        NAME "png"
        DRIVER AGG/PNG
        MIMETYPE "image/png"
        IMAGEMODE RGBA
        TRANSPARENT ON
    END
    SIZE 1024 512
    EXTENT -180 -90 180 90
    SYMBOL
        NAME "windbarb1"
        TYPE vector
        FILLED false
        POINTS
            0 0
            5 0
            -99 -99
            0 1
            1 0
        END
    END

    SYMBOL
        NAME "windbarb2"
        TYPE vector
        FILLED false
        POINTS
            0 0
            5 0
            -99 -99
            0 1
            1 0
            -99 -99
            1 1
            2 0
        END
    END

    SYMBOL
        NAME "windcalm"
        TYPE ellipse
        FILLED false
        POINTS
            1 1
        END
    END

    LAYER
        EXTENT -180 -90 180 90
        NAME "test"
        TYPE POINT
        CONNECTIONTYPE UVRASTER
        DATA out.tiff
        PROCESSING "BANDS=1,2"
        PROCESSING "UV_SPACING=32"
        PROCESSING "UV_SIZE_SCALE=1"
        PROCESSING "RESAMPLE=NEAREST"
        CLASS
            EXPRESSION ([uv_length] < 0.3)
            STYLE
                COLOR 0 0 0
                SYMBOL "windcalm"
                SIZE 5
                POSITION CC
            END
        END
        CLASS
            EXPRESSION ([uv_length] < 0.7)
            STYLE
                COLOR 0 0 0
                SYMBOL "windbarb1"
                SIZE 5
                ANGLE [uv_angle]
                POSITION CC
            END
        END
        CLASS
            EXPRESSION ([uv_length] >= 0.7)
            STYLE
                COLOR 0 0 0
                SYMBOL "windbarb2"
                SIZE 5
                ANGLE [uv_angle]
                POSITION CC
            END
        END
    END
END