User's Guide

READARCH

Copy images from an AVHRR archive tape to disk

Function:

Copy images from an AVHRR archive tape to disk. READARCH will copy any number of images from an AVHRR archive tape into a specified directory.

Parameters:

TAPEID
Tape ID. Identification number of the tape containing the desired AVHRR images.

SCENEID("*")
Scene ID. Scene ID(s) of the images to be copied from the specified tape. The default is to copy all images contained on the specified tape. See User Note 1.

OUTDIR(--)
Output directory. Directory where the images are to be placed. The default is ADAPSPROD.

DRIVE(--)
Tape drive. The name of the device on which the tape has already been mounted. If defaulted to NULL, the tape will be mounted, read, and dismounted by READARCH.

RELFLG(YES VALID=(YES,NO)
Release flag. The flag indicating whether or not to release the tape drive upon completion. Note that if DRIVE is defaulted to NULL, the tape will be dismounted by READARCH regardless of the value of RELFLG.

  = YES: Release tape drive 
  = NO:  Don't release tape drive 

Examples:

  1. LAS> readarch tapeid=041389

    All of the images stored on the archive tape 041389 will be copied to disk and placed in the ADAPSPROD directory.

  2. LAS> readarch tapeid=ss0072 sceneid=al09091187075141 outdir=[sgs4.user.images]

    The image with a scene ID of AL09091187075141 will be copied from the AVHRR archive tape SS0072 and placed in the [sgs4.user.images] directory.

  3. LAS> readarch tapeid=450689 sceneid=(ah11 al11010190135900) outdir=[usr.avhrr] drive="edcsgs4@4" relflg=no

    All images with a scene ID starting with AH11 and the image with a scene ID of AL11010190135900 will be copied from the AVHRR archive tape 450689 and placed in the directory [usr.avhrr]. Since the tape drive has been specified, the tape has presumably already been mounted. The tape will not be mounted nor dismounted.

Description/Algorithm:

READARCH mounts the specified tape, calls ARCHDR to determine which format of archive tape has been mounted, copies the image(s) into OUTDIR, and then calls INGEST to convert the image(s) into the current archive format, if necessary. If a tape drive is specified in DRIVE, READARCH will not mount the tape but will assume the tape is mounted and ready for use. Upon completion, the tape drive will be dismounted if RELFLG has been set to YES. Note however that the tape drive will be dismounted regardless of the value of RELFLG if the DRIVE parameter has not been specified.

There are five different formats of AVHRR archive tapes. EA1 and EA2 formatted tapes each contain a single AVHRR image. The scene ID for the image is not stored on the tape so a full 16 character scene ID must be entered for these tape types. The scene ID can be extracted from the production data base.

JULIAN formatted tapes are the same as EA2 formatted tapes except that an old 15 character scene ID for the image is stored on the tape. A full 16 character scene ID must be entered for these tapes.

ANSINEW and ANSIOLD formatted tapes can contain multiple images and the scene ID for each image is stored on the tape. Partial scene IDs are allowed when reading images from these tapes. See User Note 1 for an explanation of valid scene IDs.

Images read from EA1, EA2, JULIAN, and ANSIOLD tapes will be converted to the current format using INGEST.

Nonfatal Error Messages:

    None.

Fatal Error Messages:

  1. [readarch-alloc] Error allocating memory

    An error occurred allocating memory. If the error persists, contact the system administrator.

  2. [readarch-chdir] Error moving to specified directory

    READARCH was unable to change into the specified output directory. Ensure the directory has the necessary permissions.

  3. [readarch-disk] Disk space not available for 30 minutes

    The required amount of disk space has been unavailable for 30 minutes. Check the amount of space on the disk and/or specify a different output directory.

  4. [readarch-outdir] Invalid directory specification

    An invalid output directory was specified. Respecify OUTDIR.

  5. [readarch-fatal] Fatal error encountered

    A fatal error was encountered. The error message displayed prior to this message was the error encountered. Processing terminates.

  6. [readarch-fsf] Error forward skipping file

    An error occurred skipping forward on the tape. Ensure the correct tape was mounted and, if the error persists, contact the system administrator.

  7. [readarch-lib] Error determining library for <xxxxx>

    READARCH was unable to locate the command <xxxxx>. Ensure the directory containing this command is contained in the LAS global $APLIB.

  8. [readarch-njul] Multiple images found from JULIAN tape

    Multiple temporary files were found in OUTDIR. READARCH was unable to determine which image was read from the specified tape. Remove all files in OUTDIR matching the host file name of a*. and rerun. Only one READARCH should be run at a time to avoid this problem.

  9. [readarch-nscenes] Only one scene stored on an <xxx> tape

    Multiple scenes were specified for an EA1, EA2, or JULIAN formatted tape. There is only one image stored on these types of tapes so the user can only specify one scene ID in SCENEID.

  10. [readarch-parm] Error sending parameters to TAE

    READARCH was unable to pass parameter values back to TAE. Contact the system administrator.

  11. [readarch-read] Error reading image(s) from tape

    An error was encountered copying an image from an EA1 or EA2 formatted tape. If the error persists, contact the system administrator.

  12. [readarch-rsh] Permission denied to remote system <xxxxx>

    The requested tape was mounted on system <xxxxx> and the user does not have remote shell access to this system. When reading EA1 or EA2 formatted tapes, the tapes must be mounted on the current computer system or a remote system where the user has remote shell access. Rerun READARCH and notify the operators of valid systems for mounting the tape.

  13. [readarch-sid] Character <xx> of scene ID <yy> is invalid

    An invalid scene ID was found in SCENEID. Respecify SCENEID. See User Note 1.

  14. [readarch-sidlen] Scene ID must be 16 characters long

    When reading an EA1, EA2, or JULIAN formatted tape, the specified scene ID must be 16 characters long. Respecify SCENEID.

  15. [readarch-support] Error returned by <xxxxx>

    An error was returned by the specified support routine.

  16. [readarch-tape] User requested tape <xxxxx> but found <yyyyy>

    The incorrect tape was mounted. Rerun READARCH. If the error persists, contact the person responsible for mounting tapes.

  17. [readarch-ttype] Unknown tape type <xxxxx>

    The format of the tape mounted did not match one of the five AVHRR archive formats. Ensure the correct tape was mounted.

  18. [readarch-user] User interrupt

    A user interrupt was encountered.

  19. [readarch-vms] Error reading <xxx> format tape

    An error occured in reading the <xxx> format tape while running under VMS. Ensure target directory protections allow output files to be written

  20. [readarch-vax] Not enough disk space

    Not enough disk space is available on the device specified in OUTDIR. Rerun with another target disk or free at least 275,000 blocks of disk space on the device specified in OUTDIR.

User Notes:

  1. When copying images from an EA1, EA2, or JULIAN formatted archive tape, a complete 16 character scene ID must be entered. When copying images from an ANSIOLD or ANSINEW formatted archive tape, the specified scene IDs may be shorter than 16 characters.

    Valid scene IDs must conform to the following rules.

           A. The first character must be an A.
           B. The second character must be a G, H, L, or O.
           C. Characters three through 16 must be digits (0-9).
           D. For ANSIOLD and ANSINEW tapes an asterisk (*) may be
    	  used to match one or more characters of an ID.  The
    	  asterisk may be placed in any position, however, it
    	  must be the last character specified within an ID.  A
    	  single asterisk will match all scene IDs on a tape.
           E. Scene IDs with fewer than 16 characters have an
              implied asterisk at the end.
    

  2. See ARCHDR for a more complete description of the different AVHRR archive tape formats.

  3. In addition to performing the same function as READARCH, READARCH_ will return the scene IDs of the images it copies into OUTDIR.