Window an AVHRR Level 1b image from tape or disk
Window an AVHRR Level 1b image from tape or disk and create a Level 1b file on disk.
- COMMENT(--)
- Description of tape(s). A text string sent to the operator's terminal describing each tape to be mounted. COMMENT should contain the tape library identification number and a short description of the tape. This will allow the operator to ensure the correct tape is mounted. If COMMENT is defaulted, INFILE must be specified.
- DRIVE(--)
- Tape drive. The name of the drive that the Level 1b tape has been mounted on.
- SKIP(0)
- Number of files to skip. The number of files to skip on the Level 1b tape mounted on DRIVE (relative to it's current position).
- INFILE
- Name of input Level 1b file on disk. If INFILE is defaulted, COMMENT must be specified.
- OUTFILE(--)
- The output image and/or directory name. If OUTFILE is not specified, an image name will be generated from the satellite number, acquisition date, and time at the start of acquisition. This image will be place in the current working directory. If only a directory is specified, the image name will be likewise generated and placed in the specified directory.
- CHANS(--)
- AVHRR channels. The AVHRR channels to be placed in the output image. The default is to copy all of the channels in the input image to the output image.
= 1: Channel 1 = 2: Channel 2 = 3: Channel 3 = 4: Channel 4 = 5: Channel 5
- PACKFLG(YES)
- Flag to pack data. The data in the output image may be packed only if all 5 AVHRR channels are to be written.
= YES: Data will be packed. = NO: Data will not be packed.
- SL(1)
- Starting line. The line number where processing will begin (relative to North-up).
- NL(--)
- Number of lines. The number of lines to process starting at SL. If the end of the image is encountered before NL lines have been processed, processing will successfully terminate. If NULL, the entire image starting from SL will be processed.
- STATUS
- Return status. The return read status, returned to determine if EOT or EOV has been encountered (if reading from tape).
- COMMENT(--)
- Description of tape(s). A text string sent to the operator's terminal describing each tape to be mounted. COMMENT should contain the tape library identification number and a short description of the tape. This will allow the operator to ensure the correct tape is mounted. If COMMENT is defaulted, INFILE must be specified.
- DRIVE(--)
- Tape drive. The name of the drive that the Level 1b tape has been mounted on.
- SKIP(0)
- Number of files to skip. The number of files to skip on the Level 1b tape mounted on DRIVE (relative to it's current position).
- INFILE
- Name of input Level 1b file on disk. If INFILE is defaulted, COMMENT must be specified.
- OUTFILE(--)
- The output image and/or directory name. If OUTFILE is not specified, an image name will be generated from the satellite number, acquisition date, and time at the start of acquisition. This image will be place in the current working directory. If only a directory is specified, the image name will be likewise generated and placed in the specified directory.
- CHANS(--)
- AVHRR channels. The AVHRR channels to be placed in the output image. The default is to copy all of the channels in the input image to the output image.
= 1: Channel 1 = 2: Channel 2 = 3: Channel 3 = 4: Channel 4 = 5: Channel 5
- PACKFLG(YES)
- Flag to pack data. The data in the output image may be packed only if all 5 AVHRR channels are to be written.
= YES: Data will be packed. = NO: Data will not be packed.
- SLAT
- Starting latitude. The starting latitude of the window, specified in degrees.
- ELAT
- Ending latitude. The ending latitude of the window, specified in degrees.
- SLONG
- Starting longitude. The starting longitude of the window, specified in degrees.
- ELONG
- Ending longitude. The ending longitude of the window, specified in degrees.
- STATUS
- Return status. The return read status, returned to determine if EOT or EOV has been encountered (if reading from tape).
- COMMENT(--)
- Description of tape(s). A text string sent to the operator's terminal describing each tape to be mounted. COMMENT should contain the tape library identification number and a short description of the tape. This will allow the operator to ensure the correct tape is mounted. If COMMENT is defaulted, INFILE must be specified.
- DRIVE(--)
- Tape drive. The name of the drive that the Level 1b tape has been mounted on.
- SKIP(0)
- Number of files to skip. The number of files to skip on the Level 1b tape mounted on DRIVE (relative to it's current position).
- INFILE
- Name of input Level 1b file on disk. If INFILE is defaulted, COMMENT must be specified.
- OUTFILE(--)
- The output image and/or directory name. If OUTFILE is not specified, an image name will be generated from the satellite number, acquisition date, and time at the start of acquisition. This image will be place in the current working directory. If only a directory is specified, the image name will be likewise generated and placed in the specified directory.
- CHANS(--)
- AVHRR channels. The AVHRR channels to be placed in the output image. The default is to copy all of the channels in the input image to the output image.
= 1: Channel 1 = 2: Channel 2 = 3: Channel 3 = 4: Channel 4 = 5: Channel 5
- PACKFLG(YES)
- Flag to pack data. The data in the output image may be packed only if all 5 AVHRR channels are to be written.
= YES: Data will be packed. = NO: Data will not be packed.
- SLAT
- Starting latitude. The starting latitude of the window, specified in degrees.
- ELAT
- Ending latitude. The ending latitude of the window, specified in degrees.
- QUADNUM(5)
- Quadrant number. The quadrant number indicating the area that the latitude range will be selected from. (See user note 5.)
= 1: Quadrant 1 = 2: Quadrant 2 = 3: Quadrant 3 = 4: Quadrant 4 = 5: Any quadrant = 6: North Pole crossing = 7: South Pole crossing = 8: Both Poles crossed
- AREAOPT(FIRST)
- Area option. Some GAC passes can cross over an area of interest more than once. AREAOPT is used to indicate which of the multiple passes is to be selected.
= FIRST: First pass over area of interest. = SECOND: Second pass over area of interest.
- STATUS
- Return status. The return read status, returned to determine if EOT or EOV has been encountered (if reading from tape).
Tape T489 has presumably already been mounted on drive "3". The user is requesting the first image on tape T489. The output image, WESTUS, will begin with line 668 of the north-most line of the image on tape, and continue until the end of the image is reached. All channels on the tape will be processed since CHANS was not specified.
The input file "ag11042993175124;L1B" will be read from disk. The output image EASTUS will contain lines within the area between -10.5 and -5.0 degrees latitude. If more than one area within the image is defined by SLAT and ELAT, the first area will be processed (this may happen with GAC data). AVHRR channels one and two will be written to the Level 1b output image.
The input file "EASTUS;L1B" will be read from disk. The output image "COAST;L1B" will contain lines which lie between 0.0 and 10.0 degrees latitude and between 160.0 and 170.0 degrees longitude. The output 5 channel image will be in packed format.
The specified input Level 1b file on tape or disk is opened for read access. The Terabit Memory (TBM) or Archive Retrieval System (ARS) (NOAA KLM series spacecraft) header record as well as the Data Set Header (DSH) are returned. If the TBM/ARS header does not exist within the file, it is created. The AVHRR model information is loaded from the image header information. Seek to the first line of data to be processed, as specified by the user. Open the output Level 1b image file and write the TBM/ARS and DSH headers to it. These headers are relative to the window to be written to the output image. For the window of the image to be processed, read each input line, convert the data to the output format, and write it to the output image. If reading from tape, make certain that the cursor is ultimately positioned at the beginning of the next Level 1b image on tape (ready for the next call from this module). Update the header information in the output image, and close the input and output Level 1b files.
A fatal error was encountered during processing. The error message displayed immediately preceding this message is the specific error encountered.
The user must specify an input file name on disk, or a drive name upon which a Level 1b tape has been mounted. Rerun the process specifying one of these parameters.
The output file name specified by OUTFILE already exists
on disk. Rerun the process specifying another output file
name.
An error occurred opening the specified output file. Make certain that the proper directory permissions exist.
An error occurred renaming the specified output file. Make certain that a valid output file name has been specified.
An error was encountered while returning the STATUS parameter to TAE. Contact the system administrator.
Greenwich (0 degrees longitude) | | 2 | 1 | -----------+----------- Equator | (0 degrees latitude) | 3 | 4 | |When an area of interest crosses more than one quadrant and doesn't cross one or both of the poles, the quadrant number should be set to the quadrant that the pass started in. When the quadrant number is set to any quadrant (5), the image will be windowed at the starting and ending latitudes first encountered. An area of interest crossing a pole (6 or 7) should specify SLAT as the latitude before crossing the pole and ELAT as the latitude after crossing the pole. An area of interest crossing both poles (8) will use SLAT as the latitude before crossing the first pole encountered and ELAT as the latitude after crossing the other pole.