Stereo 70: The National Standard
The Stereographic 1970 (Stereo 70) projection system is the official, unitary, and mandatory system for all geodetic, cartographic, and cadastral works within Romania.
Technical Characteristics
- EPSG: 3844 (Unique code in the global registry).
- Datum: Dealul Piscului 1970.
- Ellipsoid: Krasovski 1940.
- Projection Plane: Unique, secant, with the pole in the geometric center of the country (north of Făgăraș).
Why do we use it?
Being a conformal projection (preserves angles), it is ideal for cadastre. Distortions over short distances are negligible, ensuring that the area in the deeds matches the one measured on the ground.
ETRS89: The European Standard
ETRS89 (European Terrestrial Reference System 1989) is the reference system recommended by the European Union to ensure the uniformity of cross-border geospatial data.
Major Differences from Stereo 70
- Global vs. Local: ETRS89 is a geocentric system (similar to WGS84 used by GPS), while Stereo 70 is a local system.
- Usage: ETRS89 is used for large infrastructure projects (highways, railways) crossing multiple countries and for EU reporting (INSPIRE).
The Conversion Challenge: TransDatRo
Many developers work with GPS data (WGS84/ETRS89) but must deliver documentation in Stereo 70. Warning! Conversion is not a simple mathematical formula. Romania has a network of local distortions. To transform coordinates correctly, using the official TransDatRo software (validated by ANCPI) is mandatory, as it applies the national distortion grid. Incorrect conversion (simple online tools) can lead to positioning errors of 3-5 meters!
Our Recommendation
- For Cadastre, PUG, PUZ: Work exclusively in Stereo 70.
- For Drone/GPS Surveys: Ensure raw data transformation is done using Ground Control Points (GCP) measured in Stereo 70 or through rigorous transformations (TransDat).