Geography Reference
In-Depth Information
You may be wondering which of the PROJ.4 utilities you should use.
In general,
cs2cs
is your best bet since it supports transformations
between projected coordinate system as well as datum transforms. If
you just need to go to/from a projected coordinate system to geographic
without a datum transform, the
proj
and
invproj
utilities do an accept-
able job.
9.4
More Resources
The U.S. Geological Survey has a “poster” that provides an excellent
overview of projections and the characteristic of each. The poster is
available for download free of charge.
5
Published in 1987, the USGS Professional Paper, “Map Projections: A
Working Manual” provides a good overview of projections and includes
the mathematical formulae needed to transform more than twenty-five
different coordinate systems. The paper is available online.
6
You might find it hard to believe, but an animated movie made in 1947
provides an excellent beginner's introduction to the problems of por-
traying a spherical earth on a flat surface. Entitled The Impossible Map,
the movie is available online from the National Film Board of Canada.
7
The American Society for Photogrammetry & Remote Sensing maintains
a repository of the “Grids and Datums” column from each issue of its
journal.
8
Datums and grids for a number of regions around the world
are documented in each column since 1998.
Lastly, using your favorite search engine on the term map projections
will bring up enough reading material to keep you busy for a while.
Becoming an expert on projections takes some time and effort; learning
enough to be proficient with your data is as simple as being able to
identify what you have and making your software work for you.
6.
http://www.nfb.ca/animation/objanim/en/films
(sort by title to find it)
7.
8.
Search WWH ::
Custom Search