i.tape.tm3 must be run in a location with an x,y coordinate system (i.e., a coordinate system with a projection 0.) Refer to the imagery manual entry.
Information about a TM scene can be obtained by using the -e option. It is useful to use this option before importing imagery. This option will examine the files on tape or disk and print important information about the scene. Fields printed include the file format, size of image in pixels, scene ID, and date of creation. Coordinates for the scene center or corners are given depending on the file format. For full scene and quarter scene formats, the -e option requires the volume directory file and a leader and imagery file from a single band. For the fast format, the -e option requires only a header file.
i.tape.tm3 allows the block size to be specified. This is the number of bytes to read from a tape at a time. The block size is optional; specifying it may or may not make the import run faster. The default is 32768. Look on the tape's label to find the block size. For QIC-150 tapes, the block size must be a multiple of 512 or the import will fail. The maximum allowable block size is one megabyte (1024 * 1024 = 1048576 bytes.) The block size is not used when importing from disk files.
The following sections describe the tape file formats and how to import from disk files. If you are copying imagery between tapes or to disk, it is necessary to understand how the files are arranged on tape so that i.tape.tm3 will be able to import from copied tapes correctly. If you are importing from the original tapes or exact copies there is no need to be concerned with the tape formats.
Volume Directory File
Band 1 Leader File
Band 1 Imagery File
Band 1 Trailer File
Band 2 Leader File
Band 2 Imagery File
Band 2 Trailer File
Band 3 Leader File
Band 3 Imagery File
Band 3 Trailer File
Supplemental File
When importing from tape, the program will prompt the user to mount each tape needed. Tapes may be mounted in any order. Only the tapes that contain the bands to be imported need be mounted. Be sure that tapes are rewound or positioned correctly before mounting them.
Volume Directory File landsat.ls0
Band 2 Leader File landsat.ls1
Band 2 Imagery File landsat.ls2
Band 2 Trailer File landsat.ls3
Band 3 Leader File landsat.ls4
Band 3 Imagery File landsat.ls5
Band 3 Trailer File landsat.ls6
The volume directory file must have the .ls0 suffix. Only the leader, imagery, and trailer files for the bands to be imported need be copied to disk. The prefix "landsat" is used here, but any name can be used. Each file must have a .ls# suffix, though. By naming the files this way, i.tape.tm3 can easily read the files in the correct order. Once these files are on disk, they may be imported with a command like this:
The input option specifies the prefix to use for the fileĦ names. The .ls# suffix should not be included in the input option. i.tape.tm3 will automatically append the .ls# suffix to each file in turn.
Naming the imagery files in this fashion is the easiest way to import from disk. However, i.tape.tm3 can import from files that have any names. The program will prompt for filenames. Enter the filenames at each prompt in the order that the files would be read from tape in. To import this way, omit the input option in the command, like this:
If you are importing from disk files with .ls# filenames, i.tape.tm3 will prompt for a filename at any time that it cannot find the next file to read.
Tape 1 Tape 2Tape 3
Header File Header FileHeader File
Band 1 Band 4Band 7
Band 2 Band 5
Band 3 Band 6
Because the band files have no header information in them, the only way i.tape.tm3 can tell which band is which is by the order the files come in their header file. If fast format imagery is ever copied to other tapes be sure the files are kept in the same order as they came.
To import fast format imagery from disk files, copy the files to disk using the same naming convention used for quadrant and full scenes. The header file must have a .ls0 extension. The band 1 imagery file should have a .ls1 extension, band 2 a .ls2 extension, etc. If a panchromatic band is available, give it a .ls8 extension, for lack of a better name.
If you are importing only spectral bands, the header file from any tape may be used as the .ls0 file. But if you are importing the panchromatic band, use the header file from its tape. The headers for the spectral bands and the panchromatic band are different; be sure to copy the right one to the .ls0 file before importing.
When importing the panchromatic band from fast format imagery, specify the band number as "P", like this:
If the input option is omitted, of if the program cannot find the file for a band asked for, it will prompt for a filename to be entered.
Use the dd(1) command to copy files to tapes. When copying to 9-track and 8mm tapes, just use the if and of options with a large blocksize. Use caution when copying data to QIC-150 tapes. QIC-150 tapes require all files to use record lengths that are multiples of 512. Files whose lengths are not multiples of 512 must be padded. Always use dddd with the "sync" option when copying files to QIC-150 tape, like this:
dd if=filename of=/dev/rst0 obs=32768 conv=sync
obs is the output block size; use any multiple of 512. The larger the block size the faster the copy will be done. When Landsat imagery files are copied this way they will be padded at the end, making them longer than they originally were. i.tape.tm3 will have no problem reading padded files, but other programs may.
These documents describe the file formats that i.tape.tm3 imports. They are available from EOSAT, 4300 Forbes Blvd., Lanham, MD 20706 USA.