十分强悍的墨卡托投影反算程序。方便大家下载-Very powerful anti-Mercator counting procedures. Easy to download U.S.

坐标转换工具，内涵说明。wgs84与北京54等绝大多数坐标转换。-Coordinate conversion tools, content descr iption. wgs84 the overwhelming majority of the Beijing 54 coordinate transformation.