Finding distance between 2 lat longs

最新推荐文章于 2020-10-26 19:42:05 发布

翻译最新推荐文章于 2020-10-26 19:42:05 发布 · 754 阅读

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本文讨论了如何使用SharpMap库计算两点间的地理距离，并提供了将角度单位转换为线性距离（如米）的方法。同时提到了Haversine公式，这是一种常用的计算地球表面两点间大圆距离的数学方法。

Finding distance between 2 lat longs
Tags: Geospatial Computation

gchurcher

May 15 2007 at 9:53 PM

Hi, I'd like to use the distance functions between two lat lon points but get distance in degrees rather than a more convenient distance such as metres. How do I use the SharpMap libraries to get the distance expressed as a linear unit between two points expressed as an angular unit? Thanks for any pointers.... Gavin

jo2007

May 16 2007 at 4:39 PM

Hi,

if you have the distance in degrees you can convert those to metres by yourself using the following methods:

/// <summary>
/// Degrees to radians.
/// </summary>
/// <param name="degree">Value in degrees.</param>
/// <returns>Value in radians.</returns>
private static double DegreesToRadians(double degree)
{
return degree * Math.PI / 180.0;
}

/// <summary>
/// Converts radians to meters.
/// </summary>
/// <param name="radians">Value in radians.</param>
/// <returns>Value in meters.</returns>
private static double RadiansToMeters(double radians)
{
// there are 1852 meters in a nautical mile
// Radians to Nautical Miles: radians * 60 * 180 / Math.PI

return 1852 * (radians * 10800 / Math.PI);
}

Hope that helps.

Jo

gchurcher

May 16 2007 at 9:05 PM

Thanks! I've also just discovered this page
http://www.movable-type.co.uk/scripts/latlong.html
with the Haversine formula that seems to give results.