High-Precision Coordinate Comparator

Why is this comparison needed?

Your GNSS receiver (like a smartphone) provides coordinates in **WGS84**, a dynamic global system that is constantly updated. However, Malaysia's official national standard is **GDM2000**, a static, high-accuracy system specifically tailored to our region. Because Malaysia sits on a moving tectonic plate, a coordinate measured today in WGS84 will not be the same as a GDM2000 coordinate established in the past. For precision work like surveying and engineering, we must convert WGS84 coordinates into the GDM2000 system to get a true, "apples-to-apples" comparison.

How is the calculation done?

A direct comparison of latitude and longitude is not accurate. Instead, a rigorous 3D transformation is required:

1. The WGS84 latitude, longitude, and height are converted into a 3D Cartesian (X, Y, Z) coordinate based on the WGS84 ellipsoid model of the Earth.
2. A mathematical formula, known as a 7-parameter Helmert transformation, is applied. This complex formula shifts, rotates, and scales the 3D point from the WGS84 system to align it perfectly with the GDM2000 system.
3. Finally, the new 3D (X, Y, Z) coordinate is converted back into the familiar latitude, longitude, and height format, but now correctly expressed in the GDM2000 datum.

This ensures the final difference you see is a true measure of displacement, calculated with high precision.