Cartographical Map Projections

I found the following pages useful to understand projections. The following page has information about the arguments for the different projections. http://www.ciesin.org/metadata/documentation/guidelines/spatref.html This page also has a lot of information about what makes up the different projections. In addition, it also has information regarding the formatting and syntax for the well known text format (WKT) for each of the projections: http://www.remotesensing.org/geotiff/proj_list/ OGR Simple Feature Library: The OGR Simple Features Library is a C++ open source library (and commandline tools) providing read (and sometimes write) access to a variety of vector file formats including ESRI Shapefiles, S-57, SDTS, PostGIS, Oracle Spatial, and Mapinfo mid/mif and TAB formats. It allows one to create projection information and write and read the WKT formats for projections. I am currently working on reading ERDAS Imagine's projection information and converting them into the OGRSpatialReference format.