DATUM

Description

DATUM updates the earth model portion of the segment units with the specified Earth Datum.

Parameters

datum(file, dbsl, earthd)

Name	Type	Caption	Length	Value range
FILE *	str	Input file name	1 -
DBSL	List[int]	Input segment(s)	0 -
EARTHD *	str	Earth datum	1 - 4	See description Default: D000

* Required parameter

Parameter descriptions

FILE

Specifies the name of the PCIDSK file containing the segments to modify.

DBSL

Specifies the segment(s) to update with the specified earth datum. DATUM will update the units for georeferencing, GCP, or vector segments.

EARTHD

Specifies the earth datum to use to update the segment units string. The default value is "D000" (WGS 1984).

For a detailed list of supported datums and ellipsoids, see Earth Models in the Technical Reference help section.

Details

DATUM is a utility function used to update the earth model in the units for specified database segments from an ellipsoid to the specified earth datum. No datum shifting of the segment data is done.

DATUM supports only horizontal datums; vertical datums are not supported within this context.

The FILE parameter specifies the PCISDK image file that contains the segments to update. DATUM can process georeference, vector, and GCP segments that have unit types. DBSL specifies the list of segments to process; if DBSL is not specified, DATUM updates all supported segments.

For detailed information about datum codes, see Datums in the Technical References help section.

For a list of ellipsoid codes, see Ellipsoids in the Technical References help section.

Example

Update the earth model in the vector units for vector segment 25 in the file "irvine.pix".

from pci.datum import datum

file   = 'irvine.pix' # file to update
dbsl   = [25]         # process segment 25
earthd = 'D-1'        # update the units to use "D-01"

datum(file, dbsl, earthd)