l3mapgen |

### l3mapgen

Creates a Level 3 mapped image.

Takes a product (or products if netCDF output) from an L3 bin file, reprojects the data using Proj.4 and writes a mapped file in the requested output format.

##### Location

SeaDAS-Toolbox -> SeaDAS Processors -> l3mapgen

GUI Usage
Command Line Usage

#### GUI Usage

Arguments/Keywords

UI Element Name | Type | Description | Required/Optional | Default Value
ifile | ifile | Input Level 3 bin file name. | Required |
ofile | ofile | output filename. | Required |
product | string | comma separated list of products. | Required |
apply_pal | boolean | apply color palette:
            yes: color image
            no: grayscale image
| Optional | yes
azimuth | Button | projection rotation angle in deg north. Used only for predefined projections above as required.
central_meridian | float | central meridian for projection in deg east. Used only for raw dump and predefined projections as above. | Optional | -999
datamin | float | minimum value for data scaling | Optional | default from product.xml
datamax | float | maximum value for data scaling | Optional | default from product.xml
deflate | int | netCDF4 deflation level | Optional | 4
east | float | Easternmost Longitude | Optional | file east
fudge | float | fudge factor used to modify size of L3 pixels | Optional | 1.0
interp | string | interpolation method: nearest: use the value of the nearest bin for the pixel bin: bin all of the pixels that intersect the area of the output pixel area: bin weighted by area of all the pixels that intersect the area of the output pixel | Optional | nearest
land | ifile | land mask file | Optional | $OCDATAROOT/common/landmask_GMT15ARC.nc
lat_0 | float | latitude of origin for projection in deg north. Used only for predefined projections above as required. | Optional |
lat_1 | float | latitude of first standard parallel (south). Used only for predefined projections above as required. | Optional |
lat_2 | float | latitude of second standard parallel (north). Used only for predefined projections above as required. | Optional |
lat_ts | float | latitude of true scale for projection in deg north. Used only for predefined projections above as required. | Optional |
mask_land | boolean | set land pixels to pixel value 254 | Optional | no
north | float | Northernmost Latitude | Optional | file north
num_cache | int | number of rows to cache in memory.e | Optional | 500
oformat | string | output file format :
            netcdf4: netCDF4 file, can contain more than one product
            hdf4:    HDF4 file (old SMI format)
            png:     PNG image file
            ppm:     PPM image file
            tiff:    TIFF file with georeference tags
| Optional | netcdf4
palfile | ifile | palette file name | Optional | default from product.xml
Product_rgb | string | Three products to use for RGB. Default is sensor-specific | Optional | rhos_670,rhos_555,rhos_412
projection | string | proj.4 projection string or one of the following predefined projections:
            smi:       Standard Mapped image, cylindrical projection,
                       uses central_meridian.  NSEW defaults to whole globe.
                       projection="+proj=eqc +lon_0="
            platecarree: Plate Carree image, cylindrical projection,
                       uses central_meridian.
                       projection="+proj=eqc +lon_0="
            mollweide: Mollweide projection
                       projection="+proj=moll +lon_0="
            lambert:   Lambert conformal conic (2SP) projection
                       projection="+proj=lcc +lon_0=
                                    +lat_0=
                                    +lat_1=
                                    +lat_2="
            albersconic: Albers Equal Area Conic projection
                       projection="+proj=aea +lon_0=
                                    +lat_0=
                                    +lat_1=
                                    +lat_2="
            aeqd:      Azimuthal Equidistant projection
                       projection="+proj=aeqd +lon_0=
                                    +lat_0="
            mercator:  Mercator cylindrical map projection
                       projection="+proj=merc +lon_0="
            transmerc:  Transverse Mercator cylindrical map projection
                       projection="+proj=tmerc +lon_0=
                                    +lat_0="
            utm:  Universal Transverse Mercator cylindrical map projection
                       projection="+proj=utm +zone= [+south]"
            obliquemerc:  Oblique Mercator cylindrical map projection
                       projection="+proj=omerc +gamma=0 +lat_0=
                              +lonc= +alpha=
                              +k_0=1 +x_0=0 +y_0=0"
            ease2:     EASE-Grid 2.0 projection
                       projection="EPSG:6933"
            ortho:     Orthographic projection
                       projection="+proj=ortho +lat_0= +lon_0=
                              +ellps=GRS80 +units=m"
            stere:     Stereographic projection
                       projection="+proj=stere +lat_0= +lat_ts=
                              +lon_0=
                              +ellps=WGS84 +datum=WGS84 +units=m"
            conus:     USA Contiguous Albers Equal Area Conic USGS version
                       projection="+proj=aea +lat_1=29.5 +lat_2=45.5
                             +lat_0=23.0 +lon_0=-96 +x_0=0 +y_0=0
                             +ellps=GRS80 +datum=NAD83 +units=m"
            alaska:    Alaskan Albers Equal Area Conic USGS version
                       projection="EPSG:3338"
            gibs:      latitudinally dependent projection
                       Plate Carree between 60S and 60N
                       else use Polar Sterographic
                       North Polar: projection="EPSG:3413"
                       South Polar: projection="EPSG:3031"
             raw:      Raw dump of bin file contents.
| Optional | platecarree
resolution | string | size of output pixel (default from input file) in meters or SMI dimensions:
             90km: 432 x 216 image for full globe
             36km: 1080 x 540
             18km: 2160 x 1080
             9km: 4320 x 2160
             4km: 8640 x 4320
             2km: 17280 x 8640
             1km: 34560 x 17280
             hkm: 69120 x 34560
             qkm: 138240 x 69120
             smi: 4096 x 2048
             smi4: 8192 x 4096
             land: 8640 x 4320
             #.#:  width of a pixel in meters
             #.#km:  width of a pixel in kilometers
             #.#deg:  width of a pixel in degrees
             width (int) = width of output image in pixels; supercedes resolution parameter.
| Optional | 9km
rgb_land | string | RGB value to use for land mask; comma separate string | Optional | 160,82,45
scale_type | string | data scaling type:
            linear:   linear scaling
            log:      logarithmic scaling
            arctan:   arc tangent scaling
| Optional | default from product.xml
south | float | Southern most Latitude | Optional | -999
suite | string | suite for default parameters | Optional |
threshold | float | minimum percentage of filled pixels before an image is generated | Optional | 0
use_rgb | boolean | should we use product_rgb to make a pseudo-true color image | Optional | no
use_transparency | boolean | make missing data transparent (only valid for color PNG and TIFF) | Optional | no
wavelength_3d | string | comma separated list of wavelengths for 3D products | Optional |
west | float | Western most Longitude | Optional | -999
width | int | width of output image in pixels; supercedes resolution parameter.d | Optional |

Actions/Buttons

UI Element Name | Type | Description
Browser Button | Button | Selects ifile/ofile
Load Parameters ... | Button | Reads in previously saved parameters and populates the fields in GUI.
Save Parameters ... | Button | Saves the current arguments in GUI in a file.
Run | Button | Executes the l2mapgen command with arguments provided in the UI.
Cancel | Button | Closes current processor GUI.
Apply | Button | Makes current arguments effective.
Open in SeaDAS | Checkbox | If selected, the ofile will be added to the open products list right after its generation.
? | Button | Displays the help content of the current command.

## Common proj4 formatted projection strings for direct entry:

Albers Conic Equal Area: "+proj=aea +lat_0={latitude_of_center} +lon_0={longitude_of_center} +lat_1={standard_parallel_1}"
Cylindrical Equal Area: "+proj=cea +lat_ts={standard_parallel_1} +lon_0={longitude_of_center}"
Ease2: "+proj=cea +lat_ts=30.0 +lon_0={longitude_of_center}"
Equidistant Conic: "+proj=eqdc +lat_0={latitude_of_center} +lon_0={longitude_of_center} +lat_1={standard_parallel_1}"
Lambert Azimuthal Equal Area: "+proj=laea +lat_0={latitude_of_center} +lon_0={longitude_of_center}"
Lambert Conformal Conic: "+proj=lcc +lat_1={latitude_of_origin} +lon_0={longitude_of_origin}"
Mercator: "+proj=merc +lon_0={longitude_of_origin}"
Mollweide: "+proj=moll +lon_0={central_+meridian}"
Oblique Stereographic: "+proj=sterea +lat_0={latitude_of_origin} +lon_0={longitude_of_origin}"
PlateCaree: "+proj=eqc +lon_0={central_meridian}"
Sinusoidal: "+proj=sinu +lon_0={longitude_of_center}"
SMI: "+proj=eqc +lon_0={longitude_of_center}"
Tranverse Mercator: "+proj=tmerc +lat_0={latitude_of_origin} +lon_0={longitude_of_origin}"

#### Command Line Usage

    l3mapgen 2.4.0-V2025.5 (Aug 21 2025 23:36:53)
    Usage: l3mapgen argument-list

      This program takes a product (or products if netCDF output) from an L3 bin
      or SMI file, reprojects the data using proj.4 and writes a mapped file in
      the requested output format.

      Return values
        0 = All Good
        1 = Error
        110 = No valid data to map

      The argument list is a set of keyword=value pairs.  Arguments can
      be specified on the command line, or put into a parameter file, or the
      two methods can be used together, with command line overriding.

    The list of valid keywords follows:

       help (boolean) (alias=h) (default=false) = print usage information
       version (boolean) (default=false) = print the version
            information
       dump_options (boolean) (default=false) = print
            information about each option
       dump_options_paramfile (ofile) = print
            information about each option to paramfile
       dump_options_xmlfile (ofile) = print
            information about each option to XML file
       par (ifile) = input parameter file
       suite (string) = suite for default parameters
       ifile (ifile) = input L3 bin filename

       ofile (ofile) (default=output) = output filename
       oformat (string) (default=netcdf4) = output file format
            netcdf4: netCDF4 file, can contain more than one product
            hdf4:    HDF4 file (old SMI format)
            png:     PNG image file
            ppm:     PPM image file
            tiff:    TIFF file with georeference tags
       ofile_product_tag (string) (default=PRODUCT) = sub-string in ofile name that will be substituted by the product name
       ofile2 (ofile) = second output filename
       oformat2 (string) (default=png) = second output file format
            same options as oformat
       deflate (int) (default=4) = netCDF4 deflation level

       product (string) = comma separated list of products.
            Each product can have an optional colon and modifier appended.
            For example, "product=chlor_a,chlor_a:stdev,Kd_490:nobs"
            Available modifiers:
                avg       average value (default)
                stdev     standard deviation
                var       variance
                nobs      number of observations in the bin
                nscenes   number of contributing scenes
                obs_time  average observation time (TAI93)
                bin_num   bin ID number

       wavelength_3d (string) = comma separated list of wavelengths for 3D products
       resolution (string) = size of output pixel (default from input file)
            in meters or SMI dimensions
            90km: 432 x 216 image for full globe
            36km: 1080 x 540
            18km: 2160 x 1080
             9km: 4320 x 2160
             4km: 8640 x 4320
             2km: 17280 x 8640
             1km: 34560 x 17280
             hkm: 69120 x 34560
             qkm: 138240 x 69120
             smi: 4096 x 2048
            smi4: 8192 x 4096
            land: 8640 x 4320
             #.#:  width of a pixel in meters
           #.#km:  width of a pixel in kilometers
          #.#deg:  width of a pixel in degrees
       width (int) = width of output image in pixels; supercedes resolution parameter.

       projection (string) (default=platecarree) = proj.4 projection string or one
            of the following predefined projections:
            smi:       Standard Mapped image, cylindrical projection,
                       uses central_meridian.  NSEW defaults to whole globe.
                       projection="+proj=eqc +lon_0=<central_meridian>"
            platecarree: Plate Carree image, cylindrical projection,
                       uses central_meridian.
                       projection="+proj=eqc +lon_0=<central_meridian>"
            mollweide: Mollweide projection
                       projection="+proj=moll +lon_0=<central_meridian>"
            lambert:   Lambert conformal conic (2SP) projection
                       projection="+proj=lcc +lon_0=<central_meridian>
                                    +lat_0=<scene center latitude>
                                    +lat_1=<scene south latitude>
                                    +lat_2=<scene north latitude>"
            albersconic: Albers Equal Area Conic projection
                       projection="+proj=aea +lon_0=<central_meridian>
                                    +lat_0=<scene center latitude>
                                    +lat_1=<scene south latitude>
                                    +lat_2=<scene north latitude>"
            aeqd:      Azimuthal Equidistant projection
                       projection="+proj=aeqd +lon_0=<central_meridian>
                                    +lat_0=<scene center latitude>"
            mercator:  Mercator cylindrical map projection
                       projection="+proj=merc +lon_0=<central_meridian>"
            transmerc:  Transverse Mercator cylindrical map projection
                       projection="+proj=tmerc +lon_0=<central_meridian>
                                    +lat_0=<scene center latitude>"
            utm:  Universal Transverse Mercator cylindrical map projection
                       projection="+proj=utm +zone=<utm_zone> [+south]"
            obliquemerc:  Oblique Mercator cylindrical map projection
                       projection="+proj=omerc +gamma=0 +lat_0=<lat_0>
                              +lonc=<central_meridian> +alpha=<azimuth>
                              +k_0=1 +x_0=0 +y_0=0"
            ease2:     EASE-Grid 2.0 projection
                       projection="EPSG:6933"
            ortho:     Orthographic projection
                       projection="+proj=ortho +lat_0=<lat_0> +lon_0=<central_meridian>
                              +ellps=GRS80 +units=m"
            stere:     Stereographic projection
                       projection="+proj=stere +lat_0=<lat_0> +lat_ts=<lat_ts>
                              +lon_0=<central_meridian>
                              +ellps=WGS84 +datum=WGS84 +units=m"
            conus:     USA Contiguous Albers Equal Area Conic USGS version
                       projection="+proj=aea +lat_1=29.5 +lat_2=45.5
                             +lat_0=23.0 +lon_0=-96 +x_0=0 +y_0=0
                             +ellps=GRS80 +datum=NAD83 +units=m"
            alaska:    Alaskan Albers Equal Area Conic USGS version
                       projection="EPSG:3338"
            gibs:      latitudinally dependent projection
                       Plate Carree between 60S and 60N
                       else use Polar Sterographic
                       North Polar: projection="EPSG:3413"
                       South Polar: projection="EPSG:3031"
             raw:       Raw dump of bin file contents.

       write_projtext (boolean) (default=no) = write projection information to a text file.
       central_meridian (float) (default=-999) = central meridian for projection in deg east.
            Used only for raw dump and predefined projections as above.
       lat_ts (float) = latitude of true scale for projection in deg north.
            Used only for predefined projections above as required.
       lat_0 (float) = latitude of origin for projection in deg north.
            Used only for predefined projections above as required.
       lat_1 (float) = latitude of first standard parallel (south).
            Used only for predefined projections above as required.
       lat_2 (float) = latitude of second standard parallel (north).
            Used only for predefined projections above as required.
       azimuth (float) = projection rotation angle in deg north.
            Used only for predefined projections above as required.
       utm_zone (string) = UTM zone number.
            Used only for the UTM projection;
            Append 'S' for southern hemisphere zones (e.g. 59S).
       north (float) (default=-999) = Northernmost Latitude (default: file north)
       south (float) (default=-999) = Southernmost Latitude (default: file south)
       east (float) (default=-999) = Easternmost Longitude (default: file east)
       west (float) (default=-999) = Westernmost Longitude (default: file west)
       trimNSEW (boolean) (default=no) = should we trim output
            to match input NSEW range

       interp (string) (default=nearest) = interpolation method:
            nearest: use the value of the nearest bin for the pixel
            bin:     bin all of the pixels that intersect the area of the
                      output pixel
            area:    bin weighted by area of all the pixels that intersect
                      the area of the output pixel

       apply_pal (boolean) (default=yes) = apply color palette:
            yes: color image
             no: grayscale image
       palfile (ifile) = palette filename (default from product.xml)
       use_transparency (boolean) (default=no) = make missing data transparent (only valid for color PNG and TIFF)
       datamin (float) = minimum value for scaling (default from product.xml)
       datamax (float) = maximum value for scaling (default from product.xml)
       scale_type (string) = data scaling type (default from product.xml)
            linear:  linear scaling
            log:     logarithmic scaling
            arctan:  arc tangent scaling

       quiet (boolean) (default=false) = stop the status printing
       pversion (string) (default=Unspecified) = processing version string
       use_quality (boolean) (default=yes) = should we do quality factor processing
       quality_product (string) = product to use for quality factor processing
       use_rgb (boolean) (default=no) = should we use product_rgb to make a
            pseudo-true color image
       product_rgb (string) (default=rhos_670,rhos_555,rhos_412) =
            Three products to use for RGB.  Default is sensor-specific.
       fudge (float) (default=1.0) = fudge factor used to modify size of L3 pixels
       threshold (float) (default=0) = minimum percentage of filled pixels before
            an image is generated
       num_cache (int) (default=500) = number of rows to cache in memory.
       mask_land (boolean) (default=no) = set land pixels to pixel value 254
       rgb_land (string) (default=160,82,45) = RGB value to use for land mask; comma separate string
       land (ifile) (default=$OCDATAROOT/common/landmask_GMT15ARC.nc) = land mask file
       full_latlon (boolean) (default=yes) = write full latitude and longitude arrays.

       doi (string) = Digital Object Identifier (DOI) string