MLANDC -- Magtape CCT Landsat Format

Reads LANDSAT TM imagery from a LGSOWG CCT format tape, when satellite orthorectification is required. MLANDC automatically creates a PCIDSK file, reads all of the requested imagery channels from tape, and saves the satellite path information in a segment.

The output file from MLANDC is used as input to the programs SMODEL and SORTHO.

Note: The MIL program can also be used to read LGSOWG format tapes in a more general way; however, output from MIL cannot be used for orthorectification.

Progress of this program can be monitored. See MONITOR section.

See Also: SATORTHO, CDLANDC, MSPOT, MEOSAT, MSPOTC, SMODEL, SORTHO, SHL

PARAMETERS

MLANDC is controlled by the following global parameters: 

Name     Prompt                                  Count     Type
FILE     Database File Name                      1-64      Char
MTIC     Mag Tape Input Channel list             1-16      Int
TEX1     Database Descriptive Text 1             0-64      Char
SUPPLE   Supplemental Vol: YES/NO                0-3       Char
REPORT   Report Mode: TERM/OFF/filename          1-64      Char

The following parameter receives output:

ORBIT    Orbit Segment                           1         Int

FILE

Specifies the name of the PCIDSK file to receive data. This file will be created automatically and must not already exist. 

 EASI>FILE="filespec"

MTIC

Specifies the list of channels to read from the tape. For each channel specified, a channel will be created on the PCIDSK file (FILE). 

 EASI>MTIC=i,j,...,p

TEX1

Optionally specifies a line of text describing the file. Typically this would contain information identifying the location of the data and the tape reference number. 

 EASI>TEX1="string"
Note: If TEX1 is defaulted, the following fields of the File Header in the output PCIDSK image database created will hold the following information: 

FH5   receives the tape ID, satellite Sensor and satellite Track.
FH7.1 receives the acquisition Date and scene Centre (longitude,
      latitude in decimal degrees.)
FH7.2 will be blanked for now.

SUPPLE

MLANDC will check for supplemental volume to read ephemeris data to calculate a more precise orbit. If the supplemental volume does not exist, the user can set SUPPLE to NO to speed up the program. Default is YES. 

 EASI>SUPPLE="NO"       | no supplemental volume
 EASI>SUPPLE="YES"      | use supplemental volume
 EASI>SUPPLE=           | use supplemental volume

REPORT

Specifies where the tape information report should be directed. This report contains tape header and orbital information. 

 EASI>REPORT="filename"
 EASI>REPORT=                   | defaults to terminal output
Note: The following names have special meaning: 

 EASI>REPORT="TERM"     | generates reports on your terminal
 EASI>REPORT="DISK"     | generates reports on file "IMPRPT.LST"
 EASI>REPORT="OFF"      | cancels report generation

ORBIT

This parameter receives the number of the segment in which the orbital information was saved.

DETAILS

Program MLANDC is part of the satellite orthorectification package. It is used to read LANDSAT TM imagery from a LGSOWG CCT format tape, when satellite orthorectification is required. MLANDC automatically creates a PCIDSK file, reads all of the requested imagery @@channels@@ from tape, and saves the satellite path information in a @@segment@@. Output from MLANDC is used with the SMODEL and SORTHO programs.

This program has only been tested using tapes produced in Canada and Europe (generated by ESA-EPO).

(1) CANADIAN Tapes

The Canadian LGSOWG tape makes available different levels of processing. Tapes read by the MLANDC program must conform to the following specifications:

NOTE : This program only support tapes generated by CCRS. Tapes generated by MDA-RICHMOND MERIDIAN format are not supported. The user is recommended to use level 4 tape with supplemental volume for highest accuracy.

The LANDSAT level 4 tape has two different volumes: imagery and supplemental. The imagery logical volume contains the imagery data itself and related image-synchronized information, plus ONLY that support data related to the scene. Ephemeris and attitude data are specifically excluded from this volume, as is station-specific information such as annotation data. The supplemental logical volume contains station-related processing data, such as annotation, ephemeris and attitude data, and GCP and Payload Correction (PCD) information. The user should expect to find differences in the definition of this logical volume supplied by different agencies. The supplemental volume is usually optional (user's choice) and may come before or after the imagery logical volume. For this program, the user is advised to supply the supplemental volume in order to improve the accuracy of the results. If the supplemental volume is not supplied, approximate values will be used in the program.

(2) European ESA Tapes

Level 5 full scene or quad scene TM tape must be used in this program. Since this program has only been tested using tape generated by ESA-EPO, tapes generated by other agencies are not guaranteed to work. However, PCI will modify the program for other ESA tapes, if necessary.

The MLANDC program will extract from the tape the geographic coordinates of the scene centre and the 4 corner points, and the corresponding pixel and line positions, if the values are available. The values are stored in the ORBIT segment. These points can be used as GCPs input to the SMODEL program for an approximate correction. It is useful for the case where the user cannot obtain any GCPs for an area. Since the geographic coordinates are not very accurate, the user should not expect very accurate results if those points are used.

The FILE parameter is used to specify the name of the PCIDSK file to hold the imagery and orbital information read off tape. The file is automatically created with the dimensions required to hold all of the requested data. MLANDC requires approximately 40 Mbytes of disk space per specified channel. The user must ensure that sufficient disk space is available before MLANDC is run.

The ORBIT Parameter receives the number of the segment which contains the orbital information. The orbital information in this segment is required as input to the SMODEL and SORTHO programs. The user can use the program ORBITRD and ORBITWR to check the values.

MLANDC will check for supplemental volume to read ephemeris data to calculate a more precise orbit. If the supplemental volume does not exist, the user can set SUPPLE to NO to speed up the program.

PCI wishes to acknowledge the assistance of Dr. Thierry Toutin and Yves Carbonneau at Canada Centre for Remote Sensing for providing source code and assistance of their programs. For more information about the method, please see the following papers: 

 Toutin, Th, 1985.  Analyse mathematique des possibilites
 cartographiques du systeme SPOT, These de Docteur-Ingenieur
 en Sciences Geodesiques, ENSG, Paris, France, pp 1-163.

 Toutin, Th. & Carbonneau Y.  La Multi-Stereoscopie Pour Les
 Corrections D'Images SPOT-HRV, Canadian Journal of Remote
 Sensing, p110, Vol. 15, No. 2 September, 1989.
 (This article is also available in English from the Canada
 Centre for Remote Sensing in Ottawa.)
In addition, PCI wishes to acknowledge Dr. Klaus Seidel at ETH, Zurich, in helping the support for European ESA format.

EXAMPLE

The user has received a LANDSAT TM LGSOWG format tape and wishes to perform orthorectification on the data. To get a preliminary printout of the tape header and orbital information, the program MSH in the Tape I/O package can be run (this is optional). 

 EASI>REPORT=
 EASI>STARTFIL=1
 EASI>RUN MSH
The user wishes to extract channels 1, 2, 3, 4, 5, and 7 from the tape, and store them in the file tm.pix. Note: the created file will be approximately 6 * 40 Mbytes = 240 Mbytes for a full scene. 

 EASI>FILE="tm.pix"
 EASI>MTIC=1,2,3,4,5,7
 EASI>TEX1="Toronto, Ont. Tape 1234"
 EASI>SUPPLE=
 EASI>REPORT="tm.txt"
 EASI>R MLANDC
After the tape has completed reading, the text report file tm.txt could be printed using a print utility on your system and the REPORT parameter should be reset to the terminal: 

 EASI>REPORT="TERM"
The file tm.pix could now be used as input, along with collected ground control points, to the SMODEL and SORTHO programs.

NOTES ON ACCESSING TAPE DRIVES:

If you have trouble accessing the tape drive you may have to set up the MT00 and MT0: parameters to allow the tape reading programs (such as MSH and MLANDC) to access the drive. This is described in the Installation manual that was supplied with the PCI EASI/PACE software and should have been done by your system manager. In general you would do the following: 

 EASI>MT00="MT0:"
 EASI>MT0:="device_name"    |e.g., "/dev/rmt0" on some UNIX systems
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