User's Guide

ARC2LAS

Creates a LAS image and associated files from an Arc Grid coverage.

Function:

Creates a LAS image and associated files from an Arc Grid coverage.

Parameters:

INGRID
Input Arc Grid. The name of the Arc grid to be converted. File extensions are assigned based on the band format. The input Arc grid data type may be BYTE, INTEGER*2 or INTEGER*4. Host file naming conventions of this directory must be used.

OUT
Output image. The output LAS image to be created. LAS file naming conventions must be used.

DELFLG("YES" )
Delete flag. Delete the intermediate processing files.

  = YES: Delete all intermediate processing files
  = NO:  Do not delete intermediate processing files

Example:

  1. LAS> arc2las ingrid=dark_cont out=africa delflg=no

    The Arc Grid DARK_CONT is converted to the LAS image AFRICA. The intermediate processing files are not deleted.

Description/Algorithm

ARC2LAS begins by determining if environment variables needed by Arc have been set; if not, ARC2LAS terminates. Otherwise, the Arc GRIDIMAGE module is invoked to create a temporary image file in band interleaved by line (BIL) format, and the supporting header (.hdr) and geo-location (.bilw) files.

ARC2LAS then uses the .hdr file to determine the size and data type of the input image, the projection (.prj) file for the first (or only) band to determine the map projection of the image, and the .bilw file to determine the location of the upper left corner of the image in the coordinates of this map projection. This information is placed in the output image's DDR.

TRANSLAS-IN is then called to convert the temporary image file (BIL) to LAS image format. By default ARC2LAS deletes all intermediate files.

Nonfatal Error Messages:

  1. [arc2las-badprjrec] Cannot interpret Arc projection record -- record ignored. Record text is <CCC>.

    A projection file parameter was found to be invalid. Check file for corruption and re-run if required.

  2. [arc2las-emptyzone] Arc prj file contains <zone> keyword but no value -- record ignored

    No value for the zone code was specified in the prj file.

  3. [arc2las-nocoefmap] Mapping of Arc projection parameters to LAS projection coefficents not defined -- not entered into DDR

    There is no mapping for this conversion.

  4. [arc2las-type] Unsupported projection type

    The projection type found in the Arc .prj file is not supported for conversion into the LAS DDR. Contact the system administrator for assistance.

  5. [arc2las-prjignord] Unsupported prj record type: <keyword> <value> -- record ignored

    The projection file parameter and value listed are not used for conversion.

  6. [arc2las-popen] Error opening prj file

    An error occurred while processing the Arc projection file. Check file and directory protections. This error will also occur if the ;PRJ file does not exist. Processing of the LAS DDR will complete normally with the exception that the projection information will be invalid.

  7. [arc2las-proj] Error writing projection data

    An error occurred while writing projection information to the LAS DDR. The DDR should be checked to ensure that no corruption has occurred.

  8. [arc2las-spherunkn] Spheroid type <xxxx> not supported by LAS

    The Arc spheroid type is not supported in LAS.

  9. [arc2las-unknwnuni] LAS does not support Arc projection units <xxxx>

    The projection units type in the projection file is not allowed in LAS. Valid units are FEET and METERS.

  10. [arc2las-nodatum] Datum <xxxx> unavailable

    The datum in quesion is unavailable due to one of the following reasons: a. Datum value out of valid range b. Global variable LASTABLES not defined c. Error opening datum.txt file d. Datum not in datum list e. Error opening spheroid.txt file

  11. [arc2las-notspec] Neither the datum nor spheroid is specified in the Arc file

    Neither the datum nor spheroid has been specified by the header information in the Arc file.

Fatal Error Messages:

  1. [arc2las-dtype] Invalid data type

    The data type of the input file cannot be processed into LAS. Valid data types are BYTE, INTEGER*2, and INTEGER*4.

  2. [arc2las-exists] <XXX> File already exists

    The specified file already exists. Delete it or respecify OUT and re-run the program.

  3. [arc2las-fatal] Fatal error encountered

    A fatal error was encountered during processing. The error message that is displayed immediately preceding this message is the specific error that was encountered.

  4. [arc2las-noarc] Arc not initialized

    Arc is not initialized on the current system. Setup Arc and ensure that $ARCHOME is correctly set. Re-run the program. If problems occur initializing Arc, contact the Arc system administrator.

  5. [arc2las-noexist] <XXX> File does not exist

    The specified file or directory does not exist and can not be accessed by LAS.

  6. [arc2las-open] Error opening <XXX>

    An error occurred while trying to open the specified file. Check file and directory protections.

  7. [arc2las-proc] Error processing <XXX> file

    An error occurred while processing the specified file. Check file and directory protections.

  8. [arc2las-qout] Error passing variables to TAE

    An error occurred when passing the parameter block to TAE. Contact the system administrator.

  9. [arc2las-read] Error reading <XXX> file

    An error occurred when reading the specified file. Check file and directory protections.

User Notes:

  1. The radius of the reference sphere is assumed to be 6,370,997 meters. The value for this projection parameter will be set to zero in the DDR.

  2. Refer to the TRANSLAS user guide for additional error messages.

  3. ARC2LAS may be run from the UNIX command line by using ULAS. ULAS is a function in $LASTOOLS.

        Example:
        % ulas arc2las  "/sg1/dsb/hobie/us93" "[sg2.csb.hobie]us93" "no"
    

  4. Arc/Info is invoked by the command arc. It is assumed that the Arc setup script adds the appropriate directory to your command path.