EXPORT_RASTER

EXPORT_RASTER

The EXPORT_RASTER command exports all currently loaded raster, vector, and elevation data to a file. The following parameters are supported by the command.

• FILENAME - full path to file to save the data to. When using additional name parameters with Tiling/Gridding or Polygon Cropping, this can specify just a directory, or the prefix and/or extension for the filename.
• EXPORT_LAYER - filename or description of layer(s) to export. By default all compatible and exportable layers are exported. You can include multiple EXPORT_LAYER parameters if you have multiple masks to search. Wildcards (* and ?) are supported. Hidden layers are not considered.
• TYPE

   type of raster file we're exporting to

  • FIRST_LOADED - export to the same type as the first loaded file
  • LAST_LOADED - export to the same type as the last loaded file
  • ADRG - export to an ADRG data set. See supported ADRG fields below.
  • ASRP - export to an ASRP data set. See supported ASRP fields below.
  • BIL - export to a band interleave (BIL) format file.
  • BIP - export to a band interleaved pixel (BIP) format file.
  • BMP - export to a Windows bitmap (BMP) format file.
  • BSB - export to a BSB/KAP chart file.
  • BSQ - export to a band sequential (BSQ) format file.
  • COG - exports a cloud-optimized GeoTIFF. This is a GeoTIFF with overview layers added and a tiled layout.
  • ECW - export to an ECW format file.
  • ERDAS - export to an Erdas Imagine IMG format file.
  • GEOTIFF - export to a GeoTIFF format file.
  • IDRISI_RASTER - export to an Idrisi raster format file.
  • JPEG - export to a JPG format file.
  • JPEG2000 - export to a JPEG2000 format file.
  • KML - export to a raster KML/KMZ format file for display in Google Earth.
  • NITF - NITF format imagery
  • PCX - export to a PCX format file.
  • PNG - export to a PNG format file.
  • RPF - export to a RPF (CADRG or CIB) data set. See required RPF fields below.
  • XY_COLOR - export to a XY color format file.
• SPATIAL_RES - specifies spatial resolution. Defaults to the minimum spatial resolution of the two layers if not specified. Should be formatted as x_resolution,y_resolution. The units are the units of the current global projection. For example, if UTM was the current global projection and you wanted to export at 30 meter spacing, the parameter/value pair would look like SPATIAL_RES=30.0,30.0. You can also specify as a percentage of the default resolution by adding a percent. For example to get half the detail your double the spatial resolution value, so you would use SPATIAL_RES="200%,200%".
• SPATIAL_RES_METERS - specifies spatial resolution to use in meters. The value in meters will automatically be converted to the current view/ export projection units. For example, to do an export at 2.0 meter spacing (or as close as you can get to that in the current units), use SPATIAL_RES_METERS=2.0, or to do an export at 1.0 meters in X by 1.5 meters in Y, use SPATIAL_RES_METERS="1.0,1.5".
• PIXEL_SIZE - specifies the desired size in pixels of your export. Use this instead of SPATIAL_RES if you know exactly how many pixels in size your export should be. The format is PIXEL_SIZE="widthxheight". For example, to make your export have dimensions of 1024 pixels wide by 768 pixels tall, use PIXEL_SIZE="1024x768".
• PIXEL_SIZE_MAX - specifies the maximum desired size in pixels of your export. The format is the same as the PIXEL_SIZE parameter, but specifies the maximum dimension on either side. If the dimensions result in non-square pixels, a smaller pixel count will be used in width or height so that the pixel aspect ratio is maintained.
• FORCE_SQUARE_PIXELS - if this value is set to YES, the spatial resolution of the resultant raster file will be set so that the x and y pixel size are the same, with the minimum default size being used for both.
• SAMPLING_METHOD - specifies the sampling method to use when resampling this layer. The following values are supported:
  • DEFAULT - Use either automatic resampling based on export or layer resampling, depending on setting of global flag about whether to resample on export
  • AUTO - Automatically select a resampling method based on how the export resolution and bounds compare to the original layout for a layer. For example if you export to a lower resolution a box averager of appropriate size may be used automatically
  • LAYER - Use the sampling method set for each layer
  • The list of SAMPLING_METHOD values for the The IMPORT command imports a data file for later use. To determine the proper import parameters, one option is to load the file via the interface and save a workspace. The IMPORT command and parameters will be listed in the workspace file. The following parameters are supported by the command. command can also be specified to use a particular sampling method for all layers being exported
    Shared IMPORT SAMPLING_METHOD values

    The following values are supported

    • NEAREST_NEIGHBOR - use the nearest neighbor sampling method
    • BILINEAR - use bilinear interpolation
    • BICUBIC - use bicubic interpolation
    • BOX_2X2 - use a 2x2 box average
    • BOX_3X3 - use a 3x3 box average
    • BOX_4X4 - use a 4x4 box average
    • BOX_5X5 - use a 5x5 box average
    • BOX_6X6 - use a 6x6 box average
    • BOX_7X7 - use a 7x7 box average
    • BOX_8X8 - use a 8x8 box average
    • BOX_9X9 - use a 9x9 box average
    • MAX_2X2 - use maximum value found in 2x2 box (for image layers, use brightest color)
    • MAX_3X3 - use maximum value found in 3x3 box (for image layers, use brightest color)
    • MAX_4X4 - use maximum value found in 4x4 box (for image layers, use brightest color)
    • MAX_5X5 - use maximum value found in 5x5 box (for image layers, use brightest color)
    • MAX_6X6 - use maximum value found in 6x6 box (for image layers, use brightest color)
    • MAX_7X7 - use maximum value found in 7x7 box (for image layers, use brightest color)
    • MAX_8X8 - use maximum value found in 8x8 box (for image layers, use brightest color)
    • MAX_9X9 - use maximum value found in 9x9 box(for image layers, use brightest color)
    • MED_2X2 - use median value found in 2x2 box
    • MED_3X3 - use median value found in 3x3 box
    • MED_4X4 - use median value found in 4x4 box
    • MED_5X5 - use median value found in 5x5 box
    • MED_6X6 - use median value found in 6x6 box
    • MED_7X7 - use median value found in 7x7 box
    • MED_8X8 - use median value found in 8x8 box
    • MED_9X9 - use median value found in 9x9 box
    • MIN_2X2 - use minimum value found in 2x2 box (for image layers, use darkest color)
    • MIN_3X3 - use minimum value found in 3x3 box (for image layers, use darkest color)
    • MIN_4X4 - use minimum value found in 4x4 box (for image layers, use darkest color)
    • MIN_5X5 - use minimum value found in 5x5 box (for image layers, use darkest color)
    • MIN_6X6 - use minimum value found in 6x6 box (for image layers, use darkest color)
    • MIN_7X7 - use minimum value found in 7x7 box (for image layers, use darkest color)
    • MIN_8X8 - use minimum value found in 8x8 box (for image layers, use darkest color)
    • MIN_9X9 - use minimum value found in 9x9 box (for image layers, use darkest color)
    • BLUR_3X3 - perform a Gaussian Blur using 3x3 kernel
    • BLUR_5X5 - perform a Gaussian Blur using 5x5 kernel
    • BLUR_7X7 - perform a Gaussian Blur using 7x7 kernel

• PALETTE

  Specifies the palette/image type to use. If not specified, a 24-bit RGB image will be generated.

  • KEEP_SOURCE - The exported file will use the some color configuration (if possible) as the file being exported. Note that this option is only available if you have only a single layer loaded for export.
  • OPTIMIZED (BMP, ERDAS, GEOTIFF, and PNG only) - The palette generated will be an optimal mix of up to 256 colors that will closely represent the full blend of colors in the source images. This option will generate the best results, but can more than double the export time required if any high color images are present in the export set.
  • HALFTONE (BMP, ERDAS, GEOTIFF, and PNG only) - use a 256-color halftone palette spread over the color spectrum
  • DOQ_DRG (BMP, ERDAS, GEOTIFF, and PNG only) - use a 256-color palette optimized for combined grayscale DOQs and USGS DRGs
  • DRG (BMP, ERDAS, GEOTIFF, and PNG only) - use a 256-color palette optimized for the colors found in USGS DRGs
  • GRAYSCALE - use a 256-color grayscale palette
  • BW (BMP, GEOTIFF only) - creates a black and white, 1-bit per pixel image
  • BLACKISMIN (GEOTIFF only) - creates an 8-bit per pixel grayscale image with no color map stored in the image. Black will be stored as zero with varying shades of gray up to white with a value of 255.
  • WHITEISMIN (GEOTIFF only) - creates an 8-bit per pixel grayscale image with no color map stored in the image. White will be stored as zero with varying shades of gray up to black with a value of 255.
  • JPG (GEOTIFF only) - creates a 24-bit RGB JPG-in-TIFF image. Note that while this creates a highly compressed GeoTIFF file, many software packages do not recognize JPG-in-TIFF format files.
  • MULTIBAND (BIL, BIP. BSQ, GEOTIFF, JPEG2000, ERDAS, and NITF only) - creates a multi-band image file with any number of bands of data. This is useful for multi-spectral imagery. Either 8- or 16-bits per band will be used depending on what is available in the input data. Use the NUM_BANDS parameter to specify how many bands to use. You can override the default band setting using the BAND_EXPORT_SETUP parameter (described below).
  • Custom palette filename - you can also pass in the full path to a .pal file containing a custom palette to use for the export.

• PALETTE_MAX_COLORS - specifies the maximum number of colors to use in an image-optimized or grayscale palette. The valid range is 2-256. If not specified, the value is the default max for the image format (typically 256).

• NUM_BANDS - specifies how many bands of data to export for a PALETTE=MULTIBAND export. If you don't specify a value for this the band count will be the maximum available for any of the loaded layers.
• BAND_BIT_DEPTH - specifies how many bits to use for each band of data for a PALETTE=MULTIBAND export. If you don't specify a value for this the highest bit depth of any of the input data layers will be used. The valid values are BAND_BIT_DEPTH=8, BAND_BIT_DEPTH=16, or BAND_BIT_DEPTH=32.
• BAND_EXPORT_SETUP - allows you to override the default band assignment for a MULTIBAND export. Use the following format to specify what band from what layer to use for a given export band: <output_band>?<input_band>?<layer_filename> . So for example to assign the 4th (infrared) band in an export from the 1st (red) band in a previously loaded file name C:\data\input_file.tif, use the following parameter: BAND_EXPORT_SETUP="4?1?c:\data\input_file.tif". Note that you would include a separate BAND_EXPORT_SETUP parameter for each output band that you want to setup. If you leave off the filename then all loaded data will be considered as input, with just the input-to-output band assignment being updated.
• INC_VECTOR_DATA - specifies whether or not loaded vector data should be rendered and exported to the generated image. Use a value of YES to indicate that vector data should be used. Any other value will result in vector data NOT being saved to the file.
• FILL_GAPS - specifies that small gaps in between and within the data sets being exported will be filled in by interpolating the surrounding data to come up with a color for the point in question. This option is off by default, specify FILL_GAPS=YES to turn it on.
• ONLY_GENERATE_METADATA (GEOTIFF, JPEG, and PNG only) - specifies that only metadata files like world files, TAB files, and PRJ files should be created for this file. This is useful for things like generating world and TAB files from GeoTIFF files without doing a whole new export. Just make the output filename the same as the loaded file to create the metadata for.
• SAVE_SCALE_AND_LEGEND - specifies that the distance scale and elevation legend, if applicable and enabled for display on the Configuration dialog, should be exported to the generated raster file. Specify SAVE_SCALE_AND_LEGEND=YES to enable this option.
• BG_TRANSPARENT (ECW, GEOTIFF, JPEG2000 and PNG only) - specifies that any areas of no data/background should be marked as transparent. Use BG_TRANSPARENT=YES to enable. Note: when exporting files with transparency to ECW, also use ECW_FORMAT_VERSION=3 as some other applications do not support v2 transparency.
• OVERWRITE_EXISTING - specifies that existing files should be overwritten. The default is OVERWRITE_EXISTING=YES, so use OVERWRITE_EXISTING=NO to skip exporting files that already exist.
• EXPORT_SCALE - specifies the scale to do the export at. You must also specify a DPI value in order to use the EXPORT_SCALE parameter. For example to export at 1:50,000 scale, use EXPORT_SCALE=50000.
• DPI (GEOTIFF, BMP, and JPG only or with EXPORT_SCALE parameter) - specifies the DPI (dots per inch) value to save in the generated file(s). For example, use DPI=300 to specify that the DPI for this file is 300. By default no DPI value will be written out.

• Specify Bounding Box for Operation

  See also Specify Bounds for Operation

  • GLOBAL_BOUNDS - specifies the combine bounds in units of the current global projection. There should be 4 values in a comma-delimited list following the parameter name. The values should be in order of minimum x, minimum y, maximum x, maximum y.
  • GLOBAL_BOUNDS_SIZE - specifies the combine bounds in units of the current global projection. There should be 4 values in a comma-delimited list following the parameter name. The values should be in order of minimum x, minimum y, width in x, width in y.
  • LAT_LON_BOUNDS - specifies the combine bounds in latitude/longitude degrees. There should be 4 values in a comma-delimited list following the parameter name. The values should be in order of west-most longitude, southern-most latitude, eastern-most longitude, northern-most latitude.
  • LAYER_BOUNDS - specifies that the operation should use the bounds of the loaded layer(s) with the given filename. For example, to export to the bounds of the file "c:\test.tif", you would use LAYER_BOUNDS="c:\test.tif". Keep in mind that the file must be currently loaded.
  • LAYER_BOUNDS_EXPAND - specifies that the operation should expand the used LAYER_BOUNDS bounding box by some amount. The amount to expand the bounding rectangle by should be specified in the current global projection. For example, if you have a UTM/meters projection active and want to expand the bounds retrieved from the LAYER_BOUNDS parameter by 100 meters on the left and right, and 50 meters on the top and bottom, you could use LAYER_BOUNDS_EXPAND="100.0,50.0". You can also specify a single value to apply to all 4 sides, or supply 4 separate values in the order left,top,right,bottom.
  • SNAP_BOUNDS_TO_MULTIPLE - specifies that the top-left corner of the bounding box for the operation should be snapped to a multiple of the given value. For example, using SNAP_BOUNDS_TO_MULTIPLE=1 will snap the top-left corner to the nearest whole number. The values will always go smaller for X/easting/longitude and larger to Y/northing/latitude so you always get at least what is requested.
  • SNAP_BOUNDS_TO_SPACING - specifies that the top-left corner of the bounding box for the operation should be snapped to a multiple of the resolution of the operation. For example, if you are exporting at 5 meter spacing, the top left corner will be snapped to the nearest multiple of 5. Use SNAP_BOUNDS_TO_SPACING=YES to enable or SNAP_BOUNDS_TO_SPACING=NO to disable. If not provided, the global setting for snapping exports to the nearest sample spacing boundary from the Advanced section of the General tab of the Configuration dialog will be used.
  • USE_EXACT_BOUNDS - specifies that the exact bounds that were defined in the command should be used. Generally, when the bounds specified in a command are not the same as the data bounds, the command uses the intersection between the two. When USE_EXACT_BOUNDS=YES is specified, the command will use the bounds as specified, instead of the intersection.
• Cropping to Polygons/Areas

  See also Cropping Operations to Polygons/Areas

  • POLYGON_CROP_FILE - specifies the full path and filename or loaded layer description of a vector file/loaded layer containing one or more polygon features to which the operation should be cropped. If multiple polygons are found in the specified file the polygon which has the largest intersection with the data to be combined will be used as the crop polygon (see POLYGON_CROP_USE_ALL or POLYGON_CROP_USE_EACH for exceptions).
  • POLYGON_CROP_FILE_PROJ - specifies the projection to use for the POLYGON_CROP_FILE. Use if the file doesn't have an associated projection file. See special Projection Specification for instructions.
  • POLYGON_CROP_NAME - specifies the name of a polygon shape previously defined using the DEFINE_SHAPE command to which the export should be cropped. The coordinates in the shape need to have been provided in whatever projection the new terrain layer will be in (i.e. the current projection). If you want to crop to any area features that are selected with the Digitizer Tool in the user interface rather than a defined polygon, use POLYGON_CROP_NAME="SELECTED".
  • POLYGON_CROP_USE_ALL - specifies that if a POLYGON_CROP_FILE is specified that contains multiple polygons, the operation will be cropped to all polygons in that file rather than just the best-fit polygon.
  • POLYGON_CROP_USE_EACH - specifies that if a POLYGON_CROP_FILE is specified that contains multiple polygons, the operation will generate a separate export for each polygons in that file rather than just the best-fit polygon. See the POLYGON_CROP_BBOX_ONLY and POLYGON_CROP_NAME_ATTR options for naming and other options when using this parameter. Use POLYGON_CROP_USE_EACH=YES to enable. This parameter also works with FEATHER_BLEND_EDGES. Use POLYGON_CROP_USE_EACH=YES with FEATHER_BLEND_POLY_FILE or FEATHER_BLEND_POLY to feather the edges of multiple polygons.
  • POLYGON_CROP_EXCLUDE - specifies that the crop areas are actually regions to exclude from the export rather than include. If you add POLYGON_CROP_EXCLUDE=YES to the command the results will contain everything outside the crop areas but within the full export bounds.
  • POLYGON_CROP_COMBINE_DUPS - specifies that if a POLYGON_CROP_FILE is specified that contains multiple polygons and POLYGON_CROP_USE_EACH is set, whether or not polygons with duplicate values for the attribute used for filenaming will be combined into a single export or split into separate exports. The default is POLYGON_CROP_COMBINE_DUPS=YES.
  • POLYGON_CROP_BBOX_ONLY - specifies that if the POLYGON_CROP_USE_EACH parameter is specified that each export should just be cropped to the bounding box of each polygon rather than the actual boundary of the polygon. Use POLYGON_CROP_BBOX_ONLY=YES to enable only cropping to the bounding box.
  • POLYGON_CROP_GRID_ONLY - specifies that any crop polygon(s) are used only to determine which tile/grid cells will be exported. For each tile/grid cell that intersects a crop polygon, the full tile/grid cell will be exported. Use POLYGON_CROP_GRID_ONLY=YES to enable.
  • POLYGON_CROP_INT_DATA_BOUNDS - control how the bounding box for the export is determined if a crop polygon is specified. If this option is disabled, the export bounds will be the bounds of the crop area(s), even if they extend outside the data bounds, unless you explicitly specified a bounding box in the other parameters (i.e. LAYER_BOUNDS, GLOBAL_BOUNDS, etc.). If the option is enabled, the export bounds will be the intersection of the crop area bounds and the non-cropped bounding box (i.e. full data bounds or specified bounds in other parameter). This parameter is enabled by default, use POLYGON_CROP_INT_DATA_BOUNDS=NO to disable.
  • POLYGON_CROP_NAME_ATTR - used to control the filenames generated when cropping to multiple polygons using the POLYGON_CROP_USE_EACH parameter. See special Attribute Name parameter details. This value will be appended to any filename specified in the EXPORT FILENAME parameter. If no value is provided, the exported files will be sequentially numbered.
  • POLYGON_CROP_FOLDER_ATTR - used to control the filenames generated when cropping to multiple polygons using the POLYGON_CROP_USE_EACH parameter. See special Attribute Name parameter details.
  • POLYGON_CROP_FILENAME_SUFFIX - specifies the text to insert in the output filename just before the file extension when cropping to polygons. For example, if you add POLYGON_CROP_FILENAME_SUFFIX="_out", the original FILENAME was "my_file_.dem" and the value from the polygon was "A1", you would get an output filename of "my_file_A1_out.dem".
  • POLYGON_CROP_COMPARE_STR - specifies a compare string to use to filter out the areas in the polygon crop file. See the COMPARE_STR parameter for the EDIT_VECTOR script command for details.

• Tiling / Gridding

  See also Gridding/Tiling Operations into Smaller Chunks

  • GRID_TYPE_CELL_SIZE - specifies that the export should be gridded into multiple tiles with each tile having the given size in the export projection. The value should be specified as cell width,cell height. For example, if you are exporting in a metric projection and want to tile the export into cells that are 10,000 meters wide by 5,000 meters tall, you would use GRID_TYPE_CELL_SIZE="10000.0,5000.0".
  • GRID_TYPE_PIXEL_SIZE - specifies that the export should be gridded into multiple tiles with each tile having the given size in pixels/samples. The value should be specified as cell pixel width,cell pixel height. For example, if you want to tile the export into cells that are 800 pixels wide by 600 pixels tall, you would use GRID_TYPE_PIXEL_SIZE="800,600".
  • GRID_TYPE_PIXEL_SIZE_MAX - specifies that the export should be gridded into multiple tiles with each tile having the given maximum size in pixels/samples. This works by calculating the number of rows and columns needed to hold cells of the given pixel dimensions, then shrinking those pixel dimensions down so that the tiles exactly cover the exported bounds. The value should be specified as cell pixel width,cell pixel height. For example, if you want to tile the export into cells that are at most 800 pixels wide by 600 pixels tall, you would use GRID_TYPE_PIXEL_SIZE_MAX="800,600".
  • GRID_TYPE_ROWS_COLS - specifies that the export should be gridded into multiple tiles with a given number of rows and columns of tiles. The value should be specified as number of rows,number of columns. For example, if you want to tile the export into a grid of 8 rows each 4 tiles across, you would use GRID_TYPE_ROWS_COLS="8,4".
  • GRID_OVERLAP - specifies how much to overlap tiles when gridding an export into multiple tiles. This is a percentage value from 0 to 100 and only applies when on of the GRID_TYPE_* parameters is used. For example, to make your grid tiles overlap by 5% of the grid tile size, use GRID_OVERLAP="5.0". The default value is 0.0, meaning that the tiles do not overlap.
  • GRID_OVERLAP_NUM_PIXELS - indicates whether or not the value specified in GRID_OVERLAP should be interpreted as a number of pixels instead of a percentage. Use GRID_OVERLAP_NUM_PIXELS=YES to specify that the value specified in the GRID_OVERLAP parameter should be interpreted as a number of pixels. Use GRID_OVERLAP_NUM_PIXELS=NO or omit this parameter to specify that the value is a percentage.
  • GRID_KEEP_CELL_SIZE - specifies that the size of the grid cells should be maintained over sample spacing. This means that if you specify a grid of 4 rows and 5 columns, each grid cell will be exactly 25% of the total export height and 20% of the total export width. The sample spacing may be slightly smaller than what is specified in order to achieve this. By default, the sample spacing is exactly maintained and each grid cell may be slightly larger than specified to maintain an integer number of exported cells. Use GRID_KEEP_CELL_SIZE=YES to enable.
  • GRID_NAMING - specifies how to name tiles when gridding an export into multiple tiles. The value should be SEQUENTIAL for sequential numeric naming starting at 1, SEPARATE for separate prefix appending by row and column, or SEPARATE_COLS_FIRST for separate prefix appending by columns and rows. For the SEPARATE options, use the GRID_NAMING_COLS and GRID_NAMING_ROWS parameters to specify the details of how to name the rows and columns. The value will be appended to FILENAME specified in the EXPORT command. If no GRID_NAMING parameter is supplied, the last selected grid naming options selected in the user interface will be used.
  • GRID_NAMING_COLS - specifies how to name the column portion of grid cell names when using the GRID_NAMING=SEPARATE or GRID_NAMING=SEPARATE_COLS_FIRST parameter. The value of this field is a comma-delimited list with the following field values:
    • Naming type. Can have the following values:

      • NUM - name using numbers in ascending order
      • NUM_REVERSE - name using numbers in descending order
      • ALPHA - name using letters in ascending order
      • ALPHA_REVERSE - name using letters in descending order

    • Starting value for numbering or lettering (i.e. '1', or 'A'). If the naming type is numeric you can also specify %left% or %right% as the starting value to use the left or right coordinate of the cell bounding box. For row naming you can use %top% or %bottom%.
    • Prefix string to use before the numeric or alphabetic value.
    • Step value for numeric naming (default is '1')

    You can leave values blank if they don't apply or you want to use the default. As an example, to do numeric naming starting at the number 100, increasing by 10 each time with a prefix of DEM, you would use GRID_NAMING_COLS="NUM,100,DEM,10".

  • GRID_NAMING_ROWS - specifies how to name the row portion of grid cell names when using the GRID_NAMING=SEPARATE parameter. See the documentation for the GRID_NAMING_COLS parameter above for details on the format.
  • GRID_NAMING_PREPEND_ZEROES - specifies whether or not to prepend zeroes to the start of grid column/row names. Use GRID_NAMING_PREPEND_ZEROES=NO to disable the prepending of zeroes.
  • GRID_NAMING_SEPARATOR - specifies the separator string to use between pieces of a grid name. The default is an underscore (_).
  • GRID_CREATE_FOLDERS - specifies that a separate folder should be generated for each row (or column if GRID_NAMING=SEPARATE_COLS_FIRST is specified) of the export rather than placing every output file in the same folder.
  • Tiling to Polygons/Areas - If you would like to tile your export to a series of polygons/areas, use the POLYGON_CROP_FILE and POLYGON_CROP_USE_EACH parameters. Click the link for details.