Coordinate Conversions
Our software uses in-house conversion routines built from scratch. This allows the mapping and display software to work with one system at a time and not worry about recomputing various datasets that have been merged from various sources.
Users of software like Geosoft and MapInfo are somewhat constrained to use only the ellipsoids and datums that are built in, or can only import data into the program in a fixed way. If there isn't a button or selection for what you have, then you might be out of luck.
Well, knowing the math behind datum transformations and grid projections helps to address this problem. How about the dreaded problem of a project falling half way between standard UTM zones. Some handheld GPS units only display the automatic zone so you end of flipping back and forth which makes no sense at all. You don't want to go to 10TM or Lambert Conformal, because that's just too different. One solution is to change the central meridian and use what effectively becomes a zone half-way between, like 11½.
Now, MapInfo (for instance) does a great job to combine data sets from many different coordinate systems but have you noticed how it slows down after you've imported, say, 10 different files. That's because there can be only one set coordinate system and any data not in that system must be continually recalculated everytime you change views. |