CDCARTOSAT

Description

Reads CARTOSAT imagery from a TIFF-format CD when satellite orthorectification is required. CDCARTOSAT automatically creates a PCIDSK (.pix) file, reads all of the requested imagery channels from CD, creates an RPC segment, and saves the satellite-path information in a segment. The output file from CDCARTOSAT is used as input with CATALYST Professional OrthoEngine.

Parameters

cdcartosat(fili, filo, linkfile, cdic, tex1)

Name	Type	Caption	Length	Value range
FILI *	str	Input file name	1 -
FILO *	str	Output file name	1 -
LINKFILE	str	Create linked file (NO/YES)	0 - 3	YES, NO Default: NO
CDIC	List[int]	CD input layers list	0 - 1	1 Default: 1
TEX1	str	File description	0 - 192

* Required parameter

Parameter descriptions

FILI

The path and file name of the input TIFF file.

FILO

The name of the PCIDSK file to which the processed data will be written. 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 file in which the image channel is linked to the original imagery channel. The orbital segment will still be created in FILO. The default value is NO.

CDIC

The channel to read from the CD. The CARTOSAT data product contains only one channel.

A corresponding channel is created in the output PCIDSK (.pix) file.

TEX1

A line of text to describe the file. Typically, the text identifies the location of the data and the reference number of the CD.

If no value is specified for this parameter, 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

This parameter is optional.

Details

CDCARTOSAT reads CARTOSAT TIFF file format data when satellite orthorectification is required. The corresponding metadata file (.txt) should also exist in the same directory. CDCARTOSAT automatically creates a PCIDSK file, reads the requested imagery channel from CD, creates an RPC segment and saves the satellite path information in a segment. Output from CDCARTOSAT is used with OrthoEngine.

CDCARTOSAT 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.

If the parameter LINKFILE (Create Linked File) is set to NO, the output file is automatically created with the dimensions required to hold all of the requested data. You should ensure that sufficient disk space is available before running CDCARTOSAT. If LINKFILE is set to YES, the image channel is not created; instead, it is linked to the image channel of FILI, and only one band can be linked.

Example

The user has received a CARTOSAT product in GeoTiff format CD and wants to perform orthorectification on the data. The user wants to extract channel 1 and store the data in the file bandf.pix.

from pci.cdcartosat import cdcartosat

fili = "BANDF.TIF"
filo = "bandf.pix"
linkfile = "NO"
cdic = [1]
tex1 = "Richmond Hill, Canada"

cdcartosat(fili, filo, linkfile, cdic, tex1)
	

Acknowledgements

PCI Geomatics wishes to acknowledge 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.)

M. Krishnaswamy, S. Kalyanaraman, "Indian Remote Sensing Satellite CartoSat-1: Technical features and data products" URL: http://www.gisdevelopment.net/technology/rs/techrs023.htm