User's Guide

DOQ2LAS

Convert a Digital Orthophoto Quadrangle (DOQ) into LAS

Function:

Convert a new or old format Digital Orthophoto Quadrangle (DOQ) image disk file into LAS

Parameters:

INFILE
Input DOQ file. The DOQ must conform to the published USGS standards. Host naming convention required. No windowing or sub-banding is allowed. See User Notes 1 and 2.

OUT
Output image. The output data type will be the same as the input DOQ. See User Note 6 regarding data type.

DATUM
Datum to use for output image. The (new) DOQ format contains coordinate information based on both the NAD27 and NAD83 datums. The user may select which datum to use for the output image.

Example:

  1. LAS> doq2las infile=/sg9/dsb/fsd.doq out="[sg9.dsb]fsd" datum=nad27

    The input DOQ specified by INFILE will be ingested into LAS and the image specified by OUT will be created. The associated file, fsd;dhd will be created that contains a copy of the original DOQ header. The NAD27 datum will be used.

Description/Algorithm

The DOQ specified in INFILE will be header checked to determine if it is a new or old format DOQ. The DOQ will be ingested into LAS after building a ;ddr file from information contained in the DOQ file header record(s). An additional associated file with the extension of ;dhd will be created which contains a copy of the original DOQ header. The original DOQ header contains ASCII meta data about the scene.

Nonfatal Error Messages:

  1. [doq2las-close] Error closing <XXXXX>

    A fatal error was encountered closing the specified file. Check file and directory protections and re-run the program.

  2. [doq2las-data] Unable to locate <XXXXXX>

    The specified data field was unlocatable in the DOQ header. This data field is not required for successful creation of a LAS image. Processing continues.

  3. [doq2las-datum] Secondary datum <XXXXX> not supported. Using primary (NAD83).

    The secondary datum is not NAD 27, which is the only supported secondary datum. Processsing will switch to using the primary datum (NAD 83) and continue.

  4. [doq2las-datum] Unable to locate secondary datum (NAD27). Using primary (NAD83).

    The DOQ header did not contain a "SECONDARY_HORIZONTAL_DATUM" tag. Processsing will switch to using the primary datum (NAD 83) and continue.

  5. [doq2las-nonfatal] Nonfatal error encountered

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

Fatal Error Messages:

  1. [doq2las-alloc] Error allocating memory

    An error was encountered allocating dynamic memory. Contact the system manager.

  2. [doq2las-data] Unable to locate <XXXXXX>

    The specified data field was unlocatable in the DOQ header. This data field is required for successful creation of a LAS image. Processing is terminated.

  3. [doq2las-datum] Error: Primary datum not expected value.

    The primary datum is not NAD 83, which is the only supported primary datum. Check the validity of the DOQ header.

  4. [doq2las-datum] Error: Unable to locate primary datum.

    The DOQ header did not contain a "HORIZONTAL_DATUM" tag. Check the validity of the DOQ header.

  5. [doq2las-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.

  6. [doq2las-new] Not a new DOQ

    The current DOQ was erroneously determined to be in new format. Further processing has revealed that the current DOQ is not in the new format. Contact the system manager.

  7. [doq2las-open] Error opening <XXXXX>

    An error was encountered opening the specified file. Check file and directory protections and re-run the program.

  8. [doq2las-read] Error reading <XXXXX>

    An error was encountered reading the specified file. Check file and directory protections and re-run the program.

  9. [doq2las-rewind] Error rewinding <XXXXX>

    An error was encountered while attempting to rewind a file. Check file and directory protections and re-run program.

  10. [doq2las-supp] Unsupported <XXXXX>

    A data format for DOQ files was encountered that is not supported. Contact the system administrator.

  11. [doq2las-write] Error writing <XXXXX>

    An error was encountered writing the specified file. Check file and directory protections and re-run the program.

User Notes:

  1. New DOQ files are those that are compliant with the USGS "Standards for Digital Orthophotos", dated 12/96.

  2. Old DOQ files are those that are compliant with the USGS "Standards for Digital Orhtophotos", dated 07/93.

  3. DOQ formats that precede the old and new formats defined above will not be handled by this application.

  4. Old format DOQ files that are three color RGB (containing red, green, and blue bands) files are tagged in the header as being stored in band interleaved by line (BIL) format. This is incorrect, and all old format color DOQ files will be handled as band interleaved by pixel (BIP) on ingest.

  5. Output LAS images will have a UTM projection based on the NAD27 datum.

  6. This routine only supports BYTE DOQs, as no others are generated at this time.