The GeoCoordinate class (.NET Framework 4 and higher) already has GetDistanceTo method. var sCoord = new GeoCoordinate(sLatitude, sLongitude); var eCoord = new GeoCoordinate(eLatitude, eLongitude); return sCoord.GetDistanceTo(eCoord); The distance is in meters. You need to reference System.Device.
Another option: Download the cities database from http://download.geonames.org/export/dump/ Add each city as a lat/long -> City mapping to a spatial index such as an R-Tree (some DBs also have the functionality) Use nearest-neighbour search to find the closest city for any given point Advantages: Does not depend on an external server to be available Very … Read more
Not long ago I wrote an example of the haversine formula, and published it on my website: /** * Calculates the great-circle distance between two points, with * the Haversine formula. * @param float $latitudeFrom Latitude of start point in [deg decimal] * @param float $longitudeFrom Longitude of start point in [deg decimal] * @param … Read more
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
From the picture you posted, it say it’s disabled… Go to the Developer Console Navigate to Google Maps -> APIs Search for Geocoding and click on Google Maps Geocoding API -> Enable API. Do the same thing for Geolocating
For latitudes use: Decimal(8,6), and longitudes use: Decimal(9,6) If you’re not used to precision and scale parameters, here’s a format string visual: Latitude and Longitude ##.###### and ###.###### To 6 decimal places should get you to around ~10cm of accuracy on a coordinate.