User's Guide

READMSS

Copies MSS-X archive images from an archive tape to disk and converts them into LAS.

Function:

Copies MSS-X archive images from an archive tape to a specified directory and converts them into LAS. READMSS is a tool used to verify that the MSS-X tape conversion process is running successfully.

Parameters:

TAPEID
Tape ID. Identification number of the tape containing the desired MSS-X images.

SCENEID("*")
Scene ID. Scene ID(s) of the images to be copied from the specified tape. If defaulted, all images on the tape will be copied. Valid scene IDs are 16 characters in length (See User Note 2). Specified scene IDs not found on the tape are ignored.

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

Examples:

  1. LAS> readmss tapeid=041389

    All of the images stored on the MSS-X archive tape 041389 will be copied to disk and placed in the current working directory as a LAS image.

  2. LAS> readmss tapeid=050689 sceneid=(2194023007529590 2248089007529590) outdir=[usr.mssx]

    The images with scene IDs 2194023007529590 and 2248089007529590 will be read from MSS-X archive tape 050689. LAS images 2194023007529590;img and 2248089007529590;img will be created and placed in the directory [usr.mssx] along with their associated files.

Description/Algorithm:

The MSS-X archive tapes are ansi labeled tapes containing either archive or browse images (See User Note 1). The scene ID for each image is stored on the tape. See User Note 2 for valid scene IDs.

A temporary directory OUTDIR/readmss<####> is created. READMSS calls GETDRIVE to mount the specified tape and ANSIIN to copy the specified image(s) from tape to the temporary directory. If SCENEID is "*", all files stored on TAPEID are copied to disk. If scene IDs are entered in SCENEID, only the scenes specified are copied to disk. Any scene IDs specified in SCENEID that do not exist on tape are ignored.

The temporary directory is then searched for file names that match the format "<16_char>1" (the naming convention for the first band of the images on tape). The first 16 characters of each file determine the scene ID. All images on tape are either browse (four files) or archive (seven files). The number of files on disk for each scene ID determines whether the image is archive or browse.

The image band files are renamed from <scene_id># to <scene_id>.img#, where # represents the corresponding band. If the images are archive images, associated files are renamed from <scene_id>c to <scene_id>.ncal, <scene_id>h to <scene_id>.ahdr, and <scene_id>o to <scene_id>.siat.

TRANSLAS is called to convert the image(s) into LAS and place this image in OUTDIR. After the LAS image is created, the input image files on disk, <scene_id>.img#, are deleted. The temporary directory is deleted upon completion.

Nonfatal Error Messages:

  1. [readmss-sidfnd] Scene ID <XXX> not found on tape

    The Scene ID specified does not exist on tape. Verify that the scene ID was entered correctly. This scene ID will be ignored. Processing continues with the next scene ID.

  2. [readmss-sidlen] Scene ID <XXX> must be 16 characters long

    Scene IDs must be 16 characters in length (See User Note 2). This scene ID will be ignored. Processing continues with the next scene ID.

Fatal Error Messages:

  1. [readmss-alloc] Error allocating memory

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

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

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

  3. [readmss-fatal] Fatal error encountered

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

  4. [readmss-files] Incorrect number of files per scene

    The number of files per scene id is four for browse images and seven for archive images. All files per tape are either archive or browse images. Check that the tape entered is an MSS-X archive tape.

  5. [readmss-getfile] Error searching files in directory

    An error occurred searching the files in the directory. Ensure target directory protections allow files to be read.

  6. [readmss-outdir] Invalid directory specification

    An invalid output directory was specified. Respecify OUTDIR in LAS format.

  7. [readmss-parm] Error sending parameters to TAE

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

  8. [readmss-read] Error reading image(s) from tape

    An error was encountered copying an image from an MSS-X archive tape. If the error persists, contact the system administrator.

  9. [readmss-scenes] No scenes found on disk

    No scenes were found on disk. Check that the tape is an MSS-X archive tape. If SCENEID is not '*', be sure that specified scenes are located in TAPEID.

  10. [readmss-size] Incorrect file size

    The size of the file retrieved from tape does not match the size of MSS-X archive or browse images. Check that the tape entered is an MSS-X archive tape.

User Notes:

  1. READMSS reads MSS-X 3480 archive tapes developed during the Landsat MSS-X 9-track tape conversion. Tapes may contain either archive or browse images.

    Archive images are complete four band MSS-X Landsat images. Each scene consists of seven files. Each of four files contain one band of image data, 2340 lines by 3456 samples. Information from the header, annotation, and siat files transformed to ASCII is contained in file <scene_id>h. The raw header, annotation and siat data is located in file <scene_id>o. The calibration data is located in <scene_id>c. These associated files are renamed after being read onto tape (see User Note 3).

    A Browse image exists for each scene ID. Browse images are four band images of subsampled MSS-X archive data, 390 lines by 432 samples. A separate file contains each band. No associated files exist. READMSS is not a final method of reading the MSS-X archive tapes. READMSS is a tool used to copy MSS-X archive images to disk so that they can be displayed or compared to images read directly from the 9-track tapes to verify the conversion process. The DDR that is created will contain invalid information.

  2. Scene IDs entered must contain 16 characters. The standard format for the scene IDs is SPPPRRRFFYYDDDMN, where

            S   = Satellite
            PPP = Path
            RRR = Row
            FF  = WRS Row offset (set to "00")
            YY  = Last 2 digits of Year
            M   = Mode: 1 = TM, 9 = MSS
            N   = Multiplixor:  0 for TM and MSS
    

  3. Files on line when READMSS is completed include:

    	<scene_id>.img	-- LAS four band image
    	<scene_id>.ddr	-- DDR information (invalid)
    	<scene_id>.his  -- history file
    	<scene_id>.ahdr -- ASCII header information (archive image only)
    	<scene_id>.siat -- Raw siat information (archive image only)
    	<scene_id>.ncal -- Calibration data (archive image only)
    

  4. If the system should crash while READMSS is running or if the function fails and does not clean up properly, delete the temporary directory "OUTDIR/readmss<####>" manually.