Abstract: After implementing CGCS2000 in China, massive amounts of surveying and mapping data in multi-coordinate-system and multi-format need to be coordinate transformed in many places. In practice, the top secret transformation parameters bring great difficulties to the practical application, which among geodetic coordinate systems, ellipse-centered coordinate systems and the local independent coordinate systems. Considering the security and consistency of the parameter coordinate transformation, a multiple encrypted grid interpolation coordinate transformation method is proposed in the paper, and developed into the coordinate transformation software based on two and three dimensional grid data. The method has also been applied into the ZHBDCORS. Actual verification shows that the method has the high safety and practicability.

Key words: coordinate transformation, grid interpolation, RSA, multiple encryption, CORS services based on grid