root@pathfinder.UUCP (Operator) (03/03/86)
[eat your heart out line eater] We're a graphics R&D shop with a requirement to display symbology superimposed upon a map background. This entails converting global position data (in terms of latitude/longitude values) to screen points and vice versa. Does anyone know of: 1.) Any published algorithms for commonly-used map projections (e.g. Mercator, transverse Mercator, stereographic or Lambert conformal)? 2.) Any software packages that we can adapt (we need source code, since future target machines can be just about anything)? 3.) Any method to convert between Universal Transverse Mercator (UTM) coordinates and latitude/longitude coordinates? Any suggestions would be greatly appreciated. the gnomes in Seattle Mikey my job is so secret even I don't know what I'm doing!
colonel@ellie.UUCP (Col. G. L. Sicherman) (03/11/86)
My copy of Granville's calculus gives the inverse Gudermannian as v = ln(sec q + tan q) = integral sec q dq. The corresponding Mercator projection is (lat,long) -> (ln(sec lat + tan lat), long). Of course, the angles are in radians. "What's that barking noise?" "Those are seals, Captain." "Seals? Then we must be near Easter Island." --American Pie -- Col. G. L. Sicherman UU: ...{rocksvax|decvax}!sunybcs!colonel CS: colonel@buffalo-cs BI: csdsicher@sunyabva