Polygon.GetArea Calculation

Aspose.GIS Product Family
1

Hello,
I have 2 questions about the Ploygon.GetArea method.

  1. How is GetArea calculated, please add as much detail as possible?
  2. What are the units returned?

Thanks, Zack

2

@zgreenberg GetArea method can have different behavior depend on type. Please check API Reference for different types of Geometry Enum GeometryType | Aspose.GIS for .NET API Reference Could you please provide more information about polygon which area you need to calculate.

Units are used which were used to set polygon.

3

Good day.
In order to get a correct result of the area of geometry it is necessary to transform the geometry into a coordinate system that is used metre as a unit of measurement, these are commonly projections of the earth specially designed for limited areas of the earth to avoid inaccuracies.
For example, for central Europe it is ED 1950 Albers Europe ED 1950 Albers Europe - ESRI:102013
Here’s an example

var geom = Geometry.FromText("POLYGON ((29.9524301 52.335366, 29.9524287 52.3352916, 29.9525793 52.3352902, 29.9525779 52.3353652, 29.9524301 52.335366))",
                SpatialReferenceSystem.Wgs84);
var AlbersEurope = SpatialReferenceSystem.CreateFromEpsg(102013);
var transformation = SpatialReferenceSystem.Wgs84.CreateTransformationTo(AlbersEurope);
var transformed = transformation.Transform(geom);
var area = transformed.GetArea();

And the answer will be returned in those units of measurement that are accepted for the current spatial coordinate system