Screen a project site from VN-2000 coordinates
Paste the vertex coordinate table from the cadastral survey extract or land use certificate (red book) — the tool converts to GPS using the province's correct central meridian, calculates the area, draws the boundary, cuts widths by depth and shows satellite images of the site year by year. Coordinates are not sent to CGD.
What the model calculates, and what it doesn't
Coordinates: each vertex is an X (northing) – Y (easting) pair in the planar VN-2000 system, 3° zone, scale factor 0.9999, central meridian by province (Circular 973/2001/TT-TCĐC). Converted to GPS (WGS84) coordinates using the standard 7-parameter set for VN-2000. Area = polygon area formula on the VN-2000 plane — the same method the cadastral authority uses. Cross section = width of land measured parallel to the front edge at each depth. Satellite imagery = Copernicus Sentinel-2 L2A, 10 m/pixel, the least cloudy scene picked each year and cropped to the site frame right in the browser.
Not calculated: zoning, land type, building line, safety corridors — check the local extract and zoning plan. 10 m imagery is not sharp enough for plots under about 1 ha or to pick out individual small buildings. Results do not replace the official survey records of the competent authority.
Frequently asked questions
Where do I get VN-2000 coordinates?
The cadastral survey extract, the land parcel extract or the diagram page of the red book usually has a table of vertex coordinates (X, Y columns) with side lengths. X is about 1 to 2.6 million meters (northing), Y about 100 to 900 thousand meters (easting).
Why do I need to choose a province?
Each province uses its own central meridian for cadastral maps (3° zone). If you pick the wrong province, the position on the map is off by tens to hundreds of kilometers, even though the area is still correct. Provinces merged in 2025: choose by the old boundaries at the time of survey.
Does the calculated area match the red book?
The tool calculates on the same VN-2000 plane as the cadastral authority, so results usually agree to within a few thousandths; small differences come from coordinate rounding. Larger deviations are usually caused by entering vertices in the wrong order — the tool warns when the boundary intersects itself.
Where do satellite images come from? Is there a fee?
Sentinel-2 imagery from the Copernicus program (European Union), open license, free, 10 m resolution, revisited about every 5 days since 2017. Your browser reads directly from the public Element84 image archive on AWS; CGD does not receive your coordinates.
Have real project parameters? Send them to CGD and get feedback on the design scope
This simulation stops at the principle. For a specific project, CGD builds the model on real operating data and floor plan drawings.
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