Modern web application for coordinate transformations in Greek geodetic systems.
COORD_GR is a coordinate transformation tool for Greece that converts coordinates between different geodetic reference systems and map projections.
This project is a modern web-based reimplementation of the original COORD_GR Windows application.
Original Author: Γιάννης Συγγρός (Giannis Syngros)
Original Version: 1.6.0 (30 December 2001)
Original Contact: [email protected]
Original License: Freeware
The original COORD_GR application (1998-2002) has been widely used by surveyors, GIS professionals, and government agencies in Greece for over two decades. This modernization project aims to preserve and extend its valuable functionality for a new generation of users.
- Γιάννης Συγγρός - Original COORD_GR developer (1998-2002)
- ΓΥΣ/ΕΜΠ - Transformation coefficient tables ("ΠΙΝΑΚΕΣ ΣΥΝΤΕΛΕΣΤΩΝ", 1995)
- Greek Military Geographic Service (ΓΥΣ) - Geodetic data and map sheet definitions
- National Technical University of Athens (ΕΜΠ) - Geodetic research and standards
- HATT - Old Greek Datum (Bessel ellipsoid)
- EGSA'87 (ΕΓΣΑ'87) - New Greek Datum (GRS80 ellipsoid)
- TM3 - YPECHODE 3° zones (Bessel ellipsoid)
- ED50 - European Datum 1950 (Hayford ellipsoid)
- WGS84 - World Geodetic System 1984
- ✅ Single point coordinate transformation
- ✅ Batch file processing
- ✅ Interactive map interface
- ✅ Map sheet identification
- ✅ Multiple coordinate formats
- ✅ Accuracy estimation
- ✅ Meridian convergence calculation
- ✅ Scale factor calculation
- Frontend: Vanilla JavaScript (ES6+), Leaflet.js
- Database: Supabase (PostgreSQL)
- Hosting: GitHub Pages
- Build Tool: Vite
MIT License - Modern implementation
Original COORD_GR: Freeware by Γιάννης Συγγρός
Original Author: Γιάννης Συγγρός (1998-2002)
Modern Implementation: Alexandros Liaskos (2024)
Preserving 20+ years of geodetic transformation knowledge for future generations