6
votes
1answer
177 views

How do I represent the whole Earth as a Polygon?

This is related to determining the interior of a Polygon. My difficulty is that if I specify a Polygon covering the Earth going from East to West, it will still have a boundary along the ...
6
votes
2answers
203 views

How do different GIS systems determine a Polygon's interior?

I'm interested in understanding how real-world GIS systems and their data encode Polygons. Specifically, how do they resolve the ambiguity of a Polygon's interior on a sphere? Background: in 2D, ...
4
votes
2answers
623 views

How to calculate area of 1 x 1 degree cells in a raster

I have a simple array (not geo-referenced in any way) in Matlab (which is not a language I know a huge amount about...so I can export it to other languages if needed) which has the dimensions 180 x ...
5
votes
2answers
2k views

Convert Long and Lat Co-ordinates to Square Miles

I have a set of Long and Lat co-ordinates making up a five point polygon which I have converted in excel using the following formula: ...