Sometimes lat/long are expressed in degrees/minutes/seconds, and require a N, S, E, or W direction to make sense. Decimal latitude and longitude is expressed as either a positive or negative number and doesn’t require a cardinal direction. So if you’re using decimal values for these, they aren’t described as “latitude north” or anything like that. … Read more
I’ve got XML for US state polygons here. I use them like this. I deliberately kept the detail fairly light to reduce the loading time and end up with a map that’s reasonably responsive in slow browsers. I don’t have anything for Canada.
I think the return measurement depends upon the Spatial Reference Identifiers (SRIDs) of your geography data type. The default is 4326 which is in meters. There’ a table in the DB you can check Select * from sys.spatial_reference_systems
Update: 04/2018: Vincenty distance is deprecated since GeoPy version 1.13 – you should use geopy.distance.distance() instead! The answers above are based on the Haversine formula, which assumes the earth is a sphere, which results in errors of up to about 0.5% (according to help(geopy.distance)). Vincenty distance uses more accurate ellipsoidal models such as WGS-84, and … Read more
Calculate the distance between two coordinates by latitude and longitude, including a Javascript implementation. West and South locations are negative. Remember minutes and seconds are out of 60 so S31 30′ is -31.50 degrees. Don’t forget to convert degrees to radians. Many languages have this function. Or its a simple calculation: radians = degrees * … Read more