CDLANDC -- CD CCT Landsat Format

Reads LANDSAT TM 5 and 7 imagery from a LGSOWG CCT format CD, when satellite orthorectification is required. CDLANDC automatically creates a PCIDSK file, reads all of the requested imagery channels from CD, and saves the satellite path information in a segment.

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

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

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

PARAMETERS

CDLANDC is controlled by the following global parameters: 

Name     Prompt                                  Count     Type
CDDIR    CD Directory                            1-64      Char
FILE     Database File Name                      1-64      Char
CDIC     CD Input Channel list                   1-16      Int
TEX1     Database Descriptive Text 1             0-64      Char
REPORT   Report Mode: TERM/OFF/filename          1-64      Char

The following parameters receive output:

ORBIT    Orbit Segment                           1         Int

CDDIR

Specifies the name of the CD directory. All files should be contained inside the directory. 

 EASI>CDDIR="cddir"
See example on how to enter the CDDIR for different operating systems.

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"

CDIC

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

 EASI>CDIC=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 CD 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.

REPORT

Specifies where the CD information report should be directed. This report contains CD 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"      | usually cancels report generation, but
                        | CDLANDC forces REPORT to terminal output

ORBIT

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

DETAILS

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

The file names on the CD should look like the following: 

  VDF_DAT.00n, VDF_SUP.00n, DAT_SUP.00n, LEA_0n.00n,
  DAT_01.00n, DAT_02.00n, ... , DAT_07.00n
where n is between 1 to 7.

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

(1) CANADIAN CDs

The Canadian LGSOWG CD makes available different levels of processing. CDs read by the CDLANDC program must conform to the following specifications:

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

The LANDSAT level 4 CD 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 CDs

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

The CDLANDC 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 CDDIR parameter specifies the directory name which contains the files. See example on how to enter the CDDIR for different operating systems.

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

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.

(3) Australian CDs

Old Australian CDs are produced in BIL format. CDLANDC will detect the format type automatically. The user needs to make sure to rename the files as described above and the program should work without problem.

EXAMPLE

The user has received a LANDSAT TM 5 LGSOWG format CD and wishes to perform orthorectification on the data. The user wishes to extract channels 1, 2, 3, 4, 5, and 7 from the CD, 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>CDDIR="/cdrom/SCENE1/"    | for UNIX machine
 EASI>CDDIR="D:\SCENE1\"        | for PC 
 EASI>CDDIR="[ABC.SCENE1]"      | for VMS machine

 EASI>FILE="tm.pix"
 EASI>CDIC=1,2,3,4,5,7
 EASI>TEX1="Toronto, Ont. CD 1234"
 EASI>REPORT="tm.txt"
 EASI>R CDLANDC
After the CD 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.

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