一个计算经纬度的程序，给出了详细的计算结果。

A fast, high-precision GIS projection utility which reads and writes shapefiles and supports Canadian NTv2 datum transformation along with lat/long, Transverse Mercator, and Double Stereographic projections.

For calculation of Sunset and sunrise time based on lat long.

m file to convert Lat Long geodetic coordinate system to Cartesian -m file to convert Lat Long geodetic coordinate system to Cartesian