[Proj] General Inverse Transformation

support.mn at elisanet.fi support.mn at elisanet.fi
Sat Oct 4 07:30:41 EDT 2008

An interesting paper about a general inverse transformation:


Here is the conclusion:


For the projections handled in this article forward projection functions are complex. To
derive the inverse projections fuctions, a specific method is required. The algorithm presented
here is  Newton-Rapson iteration with Jacobian matrices. It is applied to three world
projections. It can also be adapted for all cartographic projections in order to derive inverse
Since the manual calculation using this algortihm is not easy, a computer program is
needed. With such a program, data capture from analog maps produced using the projections
above can be possible. So captured data can also be easily integrated into any GIS system.


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