CDALOS

Description

CDALOS reads ALOS imagery from a LGSOW-format CD when satellite orthorectification is required. CDALOS automatically creates a PCIDSK file, reads all of the requested imagery channels from CD, and saves the satellite path information to a segment. The output file from CDALOS is used as input to OrthoEngine.

Parameters

Name	Type	Length	Value range
Header File *	String	1 -
Output: Output satellite CD layer(s) *	Raster port	1 -
OutputOrbit: Output satellite orbital ephemeris segment	ORB port	0 - 1
OutputRF: Output rational function layer	BIN port	0 - 1
CD Input Layer(s) List: CD input channel(s)	Raster port	0 - 16
File Description	String	0 -
Report	String	0 - 192	See parameter description

* Required parameter

Parameter descriptions

Header File

The full path and file name of the ALOS PRISM/AVNIR volume file.

The volume file name typically includes a prefix; for example:

• VOL-ALPSMB003062950-O1A____B
• LED-ALPSMB003062950-O1A____B

Output: Output satellite CD layer(s)

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

OutputOrbit: Output satellite orbital ephemeris segment

The name of the file to which to write the output satellite orbital ephemeris segment.

This parameter is optional.

OutputRF: Output rational function layer

The name of the file to which to write the output rational function layer.

This parameter is optional.

CD Input Layer(s) List: CD input channel(s)

The list of channels or tiles to read from the CD.

With each channel, a corresponding channel is created in the output PCIDSK file except for PRISM Level 1A, 1B1 products. For these products, only a single channel is created since each image in the product relates to a swath of the overall image. If no value is specified for this parameter, all channels or tiles will be extracted.

Up to 16 channels or tiles can be specified. Duplicate channels or tiles are NOT allowed.

File Description

A textual description of the file. Typically, the description identifies the location of the data and the CD reference number.

If no value is specified for this parameter, the file-header information in the generated output PCIDSK image includes the following:

• 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.

Report

Specifies where to direct the generated report.

Available options are:

• LOG: generates a report on the terminal (default)
• <modulename.RPT>: appends a report to the module's RPT file
• DISK: generates a report on file "IMPRPT.LST"

Details

CDALOS reads ALOS PRISM- and AVNIR-format data when satellite orthorectification is required. CDALOS automatically creates a PCIDSK file, reads all of the requested imagery channels from CD, and saves the satellite path information to a segment. The leader and imagery files must exist in the same folder as the volume file. Output from CDALOS is used in CATALYST Professional OrthoEngine.

CDALOS 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.

With PRISM Level 1B1 in NITF format, when all tiles are specified, CDALOS will create the projection in the output file. For an example of the required structure of the source data, see the Examples section.

References

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

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