CDIKONOS

Description

CDIKONOS reads IKONOS imagery from a CD for orthorectification. The corresponding metadata file must also exist in the same directory. CDIKONOS automatically creates a PCIDSK file, reads all the requested imagery channels from CD, and saves the satellite path information in a segment.

Parameters

Name	Type	Caption	Length	Value range
FILI *	String	Input file name	1 - 192
FILO *	String	Output file name	1 - 192
LINKFILE	String	Create linked file (NO/YES)	0 - 3	YES, NO Default: NO
CDIC	Integer	CD Input channel(s)	0 - 16
TEX1	String	File description	0 - 192
REPORT	String	Report mode	0 - 192	Quick links

* Required parameter

Parameter descriptions

FILI

Specifies the path and file name of the input TIFF file.

FILO

Specifies the name of the PCIDSK file that will contain the output satellite CDIKONOS image layer(s). This file will be created automatically and must not already exist.

LINKFILE

Instead of creating a new PCIDSK FILO to read the data from FILI, this parameter will create an output in which the image channel is linked to the original imagery. The orbital segment will still be created in FILO. The default value is NO.

CDIC

Optionally specifies the list of channels or layers to read from the CD. Up to four channels may be specified. If this parameter is not specified, the function reads all available channels: panchromatic images will have one available channel, multispectral images will typically have four.

For each channel, the function creates a corresponding channel in the output PCIDSK file. Duplicate channels are not allowed.

Ranges of channels or segments can be specified with negative values. For example, {1,-4,10} is internally expanded to {1,2,3,4,10}. When you are not specifying a range in this way, only 48 numbers can be specified explicitly.

TEX1

Optionally specifies a line of text that describes the file. Typically, this contains information that identifies the location of the data and the CD reference number.

If TEX1 (File Description) is not specified, the File Header fields in the generated output PCIDSK image database hold the following information:

• FH5 receives the tape ID, satellite sensor, and satellite track
• FH7.1 receives the acquisition date and scene center (longitude and latitude, in decimal degrees)
• FH7.2 is empty

REPORT

Specifies where to direct the generated report.

Available options are:

• TERM: generates a report on the terminal (default)
• DISK: generates a report on file "IMPRPT.LST"
• OFF: turns off report generation
• <filename>: appends a report to the specified file

Details

CDIKONOS is part of the satellite orthorectification component. It reads an IKONOS TIFF-format CD when satellite orthorectification is required. The corresponding metadata file must also exist in the same directory. CDIKONOS automatically creates a PCIDSK file, reads all the requested imagery channels from CD, and saves the satellite path information in a segment.

For color data in separate files, the channel numbers 1, 2, 3 and 4 correspond to the red, green, blue, and near-infrared data.

CDIKONOS extracts from the CD the geographic coordinates of the scene center and the four corner points. The values are stored in the output orbit segment. These points can be used as ground control point (GCP) input for an approximate correction, which is useful when GCPs are unavailable for an area. Note, however, that using geographic coordinates may not produce very accurate results. To ensure an accurate calculation, a sufficient number of GCPs must be used for each scene or block of scenes.

If the LINKFILE parameter is set to NO, the output file is automatically created with the dimensions required to hold all of the requested data. Ensure that sufficient disk space is available before running CDIKONOS. If LINKFILE is set to YES, the image channel is not created; instead, it is linked to the image channel of FILI. For stereo data, LINKFILE is ignored and a new file is created because rotation is required when reading the data.

Example

The current working directory contains the IKONOS image file po_81676_pan_0010000000.tif, and the metadata file po_81676_metadata.txt. The single channel of the file is imported to a PCIDSK database.

EASI>FILI="po_81676_pan_0010000000.tif"   ! input IKONOS image
EASI>FILO="CDIKONOS_1.pix"   ! imported IKONOS PCIDSK file
EASI>LINKFILE="NO"
EASI>CDIC=1
EASI>TEX1="Image No. 1"
EASI>REPORT="ikonos.txt"

EASI>R CDIKONOS

Acknowledgements

PCI Geomatics acknowledges the assistance of Dr. Thierry Toutin for this software.

References

Toutin, Th. "Analyse mathématique des possibilités cartographiques du système SPOT". Thèse de Docteur-Ingénieur en Sciences Géodésiques, ENSG, Paris, France, 1985. pp1 -163.

Toutin, Th. and Carbonneau Y. "La multi-stéréoscopie pour les corrections d'images SPOT-HRV", Canadian Journal of Remote Sensing, Vol. 15, No. 2 (September 1989) p110. (Also available in English from the Canada Centre for Remote Sensing.)