CDIRSS

Description

CDIRSS reads IRS imagery from an IRS Super Structure format CD when satellite orthorectification is required. CDIRSS automatically creates a PCIDSK file, reads all the requested imagery channels from the CD, and saves the satellite path information to one or two segments. The generated file from CDIRSS is used as input for SATMODEL and ORTHO2.

Parameters

Name	Type	Caption	Length	Value range
FILEHD*	String	Input file header name	1 - 192
FILE*	String	Output file name	1 - 192
CDIC*	Integer	CD input channel(s)	1 - 16
TEX1	String	Descriptive text	0 - 192
ORBIT	Integer	Output orbit segment	0 - 1
REPORT	String	Report mode	0 - 192	Quick links
MONITOR	String	Monitor mode	0 - 3	ON, OFF Default: ON

* Required parameter

Parameter descriptions

FILEHD

Specifies the full path and file name of the IRSS volume file.

FILE

Specifies the name of the PCIDSK file that will receive the processed data. This file is created automatically and must not already exist.

CDIC

Specifies the list of channels or layers to read from the CD. Up to 16 channels may be specified.

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

If this parameter is not specified, all channels will be read from the file.

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 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

ORBIT

ORBIT is an output parameter. Upon completion, CDIRSS writes the number of the output segment containing the orbital information to this parameter. This value may be used as input for other functions.

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

MONITOR

The program progress can be monitored by printing the percentage of processing completed. A system parameter, MONITOR, controls this activity.

Available options are:

• ON: Turns the monitor ON (default)
• OFF: Turns the monitor OFF (recommended if running in batch or background mode)

Details

CDIRSS is part of the satellite orthorectification component. It reads the IRS imagery from a Super Structure LGSOWG format CD when satellite orthorectification is required. CDIRSS automatically creates a PCIDSK file, reads all the requested imagery channels from the CD, and saves the satellite path information in one or two segments. The output is used as input SATMODEL and ORTHO2.

The IRS Super Structure tape provides access to different levels of processing. CDIRSS supports level 0 and level 1 CDs. Level 0 is raw and level 1 is radiometrically corrected.

If the file names on the CD are not identical, you may copy the files on to the hard disk and rename them.

CDIRSS extracts from the CD the geographic coordinates of the scene center and the four corner points. The values are stored in the orbit segment in the generated image.pix file. 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.

The FILE parameter specifies the name of the PCIDSK file that holds the image and orbital information obtained from the CD. This file is automatically created with the dimensions required to hold all of the requested data. Before running CDIRSS, ensure that sufficient disk space is available.

The ORBIT parameter receives the segment number that contains the orbital and altitude information; this information is required for SATMODEL and ORTHO2.

Example

Perform an orthorectification on the data obtained from the IRS panchromatic Super Structure format CD. Extract channel 1 and store it in the irvine.pix file. The volume descriptor file is named volume1.pan.

EASI>FILEHD="/cdrom/volume1.pan"       ! Used for UNIX.
EASI>FILEHD="D:\volume1.pan"           ! Used for Windows.
EASI>FILEHD="[ABC.volume1.pan]"        ! Used for a VMX computer.
EASI>FILE="irvine.pix"
EASI>CDIC=1
EASI>TEX1="Irvine  CD 1234"
EASI>REPORT="irvine.txt"

EASI>R CDIRSS