Using Projections and Coordinate Systems

The default coordinate system is longitude and latitude. The following GISDK functions include a Projection option for specifying another coordinate system when importing into or exporting from a geographic file:

GISDK Function	Description
CreateGrid	Creates a geographic file of features on a regular grid
ExportCSV	Exports features in a geographic file to a Caliper text geography file
ExportDXF	Exports features in a geographic file to a DXF file
ImportArcViewShape	Imports features from an ArcView Shapefile into a geographic file
ImportBNA	Imports features from a BNA file into a geographic file
ImportCSV	Imports features from a Caliper text geography file into a geographic file.
ImportDXF	Imports features from a DXF file into a geographic file
ImportE00	Imports features from an ARC/INFO export (.E00) file into a geographic file
ImportFromView	Creates a geographic file of point features from coordinates in a view
ImportMIF	Imports features from an MIF file into a geographic file

The Projection option takes two parameters:

A string containing the projection specification, which identifies the projection or coordinate system
An array of option strings.

A large number of standard coordinate systems are supported, including State Plane Coordinates for NAD27 and NAD83 in the U.S., and coordinate systems for countries all over the world. A standard coordinate system is based on a pre-defined projection, so you only need to specify the coordinate system.

A large number of projections are also supported, including Universal Transverse Mercator (UTM) and Gauss-Kruger, both of which have defined coordinate system zones. For other projections, you can define a custom coordinate system. The definition can specify an ellipsoid.

You can use the Transform option with the Projection option to correct coordinates that may have been modified from their standard form (e.g., 1,000,000 subtracted to save storage space).

The following sections will describe how to use:

Standard coordinate systems
Your own coordinate systems
The UTM projection with a coordinate system zone
The Gauss-Kruger projection with a coordinate system zone
Other projections with a custom coordinate system
Units of measure
Ellipsoids, with a list of the ellipsoids used by common datums
Transformations
Datum conversions, between U.S. and other datums
Projections as settings for maps

See "Projections and Coordinate Systems" in the Maptitude Help for further information.