Note this is a tricky polygon in Antarctica: http://www.gcmap.com/mapui?P=79.736894381S+0.780387531W-79.736894381S+170.375361283E-79.692508368S+170.375361283E-79.692508368S+0.780387531W-79.736894381S+0.780387531W&MS=wls&DU=km
The area is 899078042.2 m2 as verified using: https://geographiclib.sourceforge.io/cgi-bin/Planimeter?type=polygon&rhumb=geodesic&radius=6378137&flattening=1%2F298.257223563&input=-79.736894381+-0.780387531%0D%0A-79.736894381+170.375361283%0D%0A-79.692508368+170.375361283%0D%0A-79.692508368+-0.780387531%0D%0A-79.736894381+-0.780387531&option=Submit PostGIS uses GeoGraphicLib's method (https://doi.org/10.1007/s00190-012-0578-z) which has high accuracy. The bug is likely with other resources. On Wed, 26 Mar 2025 at 05:58, Alexander Trufanov <trufano...@gmail.com> wrote: > > Hello, > > I've a following area calculation: > > select ST_Area( > ST_GeometryFromText('POLYGON ((-0.780387531 -79.736894381, > 170.375361283 -79.736894381, > 170.375361283 -79.692508368, > -0.780387531 -79.692508368, > -0.780387531 -79.736894381))', 4326)::geography) /1000000 > > which returns ~900 km^2 > > while ST_Perimeter() for the same geography is ~4600km > and If I open ST_AsGeoJson() of this geometry in google earth pro and some > websites I'm getting ~ 16700 km^2. > It seems it's a correct result and ST_Area() result is wrong. > > Is this a known problem? > > My versions: > PostgreSQL 15.10 (Debian 15.10-astra.se1) on x86_64-pc-linux-gnu, compiled by > gcc (Astra 12.2.0-14.astra3+b1) 12.2.0, 64-bit > POSTGIS="3.3.2 68f4434" [EXTENSION] PGSQL="150" GEOS="3.11.1-CAPI-1.17.1" > PROJ="9.1.1" GDAL="GDAL 3.6.2, released 2023/01/02" LIBXML="2.9.14" > LIBJSON="0.16" LIBPROTOBUF="1.4.1" WAGYU="0.5.0 (Internal)" RASTER > > -- > With best regards, > Truf
