User's Guide

PUSHL1B

Generate and transfer Level-1b AVHRR images

Function:

PUSHL1B will identify, generate, and transfer Level-1b AHVRR images to a remote server.

Parameters:

ARCHDIR
Archive directory. The name of the directory from which to transmit images.

STOPFILE
Stop file name. The name of the file used to signal the graceful termination of this process. This file is usually generated by running the ADAPSTOP module.

LOGFILE
Log file name. The name of the file where all processing messages will be logged with a date and time stamp. An extension of ";log" is assumed.

Example:

  1. LAS> pushl1b archdir="[somedir.archive]" stopfile="[somedir]pushnoa.stop" logfile="[logdir]pushnoa"

    PUSHL1B will look in the [somedir.archive] directory. For each AVHRR Level-0 image that it finds, it will generate a Level-1b copy of the image and transfer the Level-1b copy of the image to the primary NOAA server. If this transfer fails, it will try to transfer the image to secondary NOAA server. If the second transfer attempt fails, PUSHL1B will terminate. If the file "[somedir]pushnoa;stop" is detected during the execution of PUSHL1B, it will cause PUSHL1B to terminate gracefully. All error and processing messages will be written to "[logdir]pushnoa;log".

Description/Algorithm:

PUSHL1B looks for Level-0 AVHRR images residing in the ARCHDIR directory. If an image is found, the following steps are performed: For each image found, lock it so that another instance of PUSHL1B does not try to also process it. Generate a Level-1b copy of the image and try to transfer the Level-1b image to the primary remote system. If this transfer fails, try to transfer the Level-1b image to the secondary remote system. Upon successful transfer of the image, unlock the image and delete the Level-0 and Level-1b version of the image. PUSHL1B will iteratively find and process images until it doesn't find any more to process.

Nonfatal Error Message:

    None.

Fatal Error Messages:

  1. [pushl1b-fatal] Fatal error encountered

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

  2. [pushl1b-cd] Error moving into the file directory

    An error was encountered moving into the ARCHDIR directory. Ensure that this directory exists with the proper permissions.

  3. [pushl1b-stp] Error determining if stop file exists

    An error was encountered while determining if the stop file exists. Contact the system administrator if this error persists.

  4. [pushl1b-ustop] ARCHIVE terminated by user

    ARCHIVE was terminated by the user.

  5. [pushl1b-wild] Error determining if an image exists

    An error was encountered while determining if an AVHRR image exists for processing. Contact the system administrator if this error persists.

  6. [pushl1b-nam] Error locking image for processing

    An error was encountered while attempting to lock the AVHRR image prior to processing it. Contact the system administrator if this error persists.

  7. [pushl1b-ulck] Error unlocking the image

    An error was encountered while attempting to unlock the AVHRR image after processing it. Contact the system administrator if this error persists.

  8. [pushl1b-abort] User aborted PUSHL1B

    PUSHL1B was aborted by the user.

  9. [pushl1b-scr] Failed to determine script name

    The script used to automatically transfer the Level-1b image could not be found. Contact the system administrator if this error persists.

  10. [pushl1b-l1b] Error generating Level-1b image

    An error occurred while trying to generate a Level-1b image. Ensure that you have write permission in the directory specified by ARCHDIR.

  11. [pushl1b-tran] Failed to transfer pending scene

    An error occurred while trying to transfer the image to the specified remote server. If this error occurs for both primary and secondary servers, the image is not transferred, try again later. If this error occurs for only the primary server, the image was apparently successfully transferred to the secondary server, and no action is required.

  12. [pushl1b-del] Error deleting the image

    An error occurred while trying to delete either the Level-0 image or the Level-1b image. Ensure that they exist with the proper permissions.

User Notes:

  1. PUSHL1B is part of the PUSHNOA module, but is robust enough to potentially be used by other modules in the future.

  2. This module expects the files 'password.server1' and 'password.server2' to exist in the ADAPSTABLES directory. The contents of these files is expected to be:

    "USER PASSWORD SERVER DIRECTORY"

    where:

       USER       is the user id on the remote server
       PASSWORD   is the password of the user on the
    	      remote server
       SERVER     is the IP address of the remote server
       DIRECTORY  is the appropriate directory on the remote
    	      server