Purpose: This tool converts coordinates between Local site coordinate systems and Global OSGB15 coordinates using a 2D Helmert transformation. Perfect for site surveys where you need to transform between your local grid and national coordinates.

How it works:

1. Enter two base points that you know in both coordinate systems
2. Choose your conversion direction (Local → Global or Global → Local)
3. Add the points you want to transform
4. Click "Convert Coordinates" to see results
5. Export your results to clipboard or CSV file

Note: The transformation calculates scale, rotation, and translation parameters automatically from your base points to ensure accurate coordinate conversion.