我在这里发布了我的工作示例。

在MySQL中列出表中指定点(我们使用一个随机点- lat:45.20327, long:23.7806)之间距离小于50 KM的所有点(表中字段为coord_lat和coord_long):

列出所有距离<50，单位:公里(地球半径6371公里):

SELECT denumire, (6371 * acos( cos( radians(45.20327) ) * cos( radians( coord_lat ) ) * cos( radians( 23.7806 ) - radians(coord_long) ) + sin( radians(45.20327) ) * sin( radians(coord_lat) ) )) AS distanta 
FROM obiective 
WHERE coord_lat<>'' 
    AND coord_long<>'' 
HAVING distanta<50 
ORDER BY distanta desc

上面的例子是在MySQL 5.0.95和5.5.16 (Linux)中测试的。

下面是一个c#实现:

static class DistanceAlgorithm
{
    const double PIx = 3.141592653589793;
    const double RADIUS = 6378.16;

    /// <summary>
    /// Convert degrees to Radians
    /// </summary>
    /// <param name="x">Degrees</param>
    /// <returns>The equivalent in radians</returns>
    public static double Radians(double x)
    {
        return x * PIx / 180;
    }

    /// <summary>
    /// Calculate the distance between two places.
    /// </summary>
    /// <param name="lon1"></param>
    /// <param name="lat1"></param>
    /// <param name="lon2"></param>
    /// <param name="lat2"></param>
    /// <returns></returns>
    public static double DistanceBetweenPlaces(
        double lon1,
        double lat1,
        double lon2,
        double lat2)
    {
        double dlon = Radians(lon2 - lon1);
        double dlat = Radians(lat2 - lat1);

        double a = (Math.Sin(dlat / 2) * Math.Sin(dlat / 2)) + Math.Cos(Radians(lat1)) * Math.Cos(Radians(lat2)) * (Math.Sin(dlon / 2) * Math.Sin(dlon / 2));
        double angle = 2 * Math.Atan2(Math.Sqrt(a), Math.Sqrt(1 - a));
        return angle * RADIUS;
    }

}

下面是SQL实现，以km为单位计算距离，

SELECT UserId, ( 3959 * acos( cos( radians( your latitude here ) ) * cos( radians(latitude) ) * 
cos( radians(longitude) - radians( your longitude here ) ) + sin( radians( your latitude here ) ) * 
sin( radians(latitude) ) ) ) AS distance FROM user HAVING
distance < 5  ORDER BY distance LIMIT 0 , 5;

要获得通过编程语言实现的更多细节，您可以浏览这里给出的php脚本

我通过简化公式来简化计算。

下面是Ruby版本:

include Math
earth_radius_mi = 3959
radians = lambda { |deg| deg * PI / 180 }
coord_radians = lambda { |c| { :lat => radians[c[:lat]], :lng => radians[c[:lng]] } }

# from/to = { :lat => (latitude_in_degrees), :lng => (longitude_in_degrees) }
def haversine_distance(from, to)
  from, to = coord_radians[from], coord_radians[to]
  cosines_product = cos(to[:lat]) * cos(from[:lat]) * cos(from[:lng] - to[:lng])
  sines_product = sin(to[:lat]) * sin(from[:lat])
  return earth_radius_mi * acos(cosines_product + sines_product)
end

要计算球体上两点之间的距离，你需要做大圆计算。

如果你需要将距离重新投影到平面上，MapTools中有许多C/ c++库可以帮助你进行地图投影。要做到这一点，你需要不同坐标系的投影字符串。

你可能还会发现MapWindow是一个可视化点的有用工具。此外，由于它是开源的，它是如何使用project.dll库的有用指南，它似乎是核心的开源投影库。

下面是VB的实现。NET，这个实现将根据您传递的Enum值以KM或Miles为单位给您结果。

Public Enum DistanceType
    Miles
    KiloMeters
End Enum

Public Structure Position
    Public Latitude As Double
    Public Longitude As Double
End Structure

Public Class Haversine

    Public Function Distance(Pos1 As Position,
                             Pos2 As Position,
                             DistType As DistanceType) As Double

        Dim R As Double = If((DistType = DistanceType.Miles), 3960, 6371)

        Dim dLat As Double = Me.toRadian(Pos2.Latitude - Pos1.Latitude)

        Dim dLon As Double = Me.toRadian(Pos2.Longitude - Pos1.Longitude)

        Dim a As Double = Math.Sin(dLat / 2) * Math.Sin(dLat / 2) + Math.Cos(Me.toRadian(Pos1.Latitude)) * Math.Cos(Me.toRadian(Pos2.Latitude)) * Math.Sin(dLon / 2) * Math.Sin(dLon / 2)

        Dim c As Double = 2 * Math.Asin(Math.Min(1, Math.Sqrt(a)))

        Dim result As Double = R * c

        Return result

    End Function

    Private Function toRadian(val As Double) As Double

        Return (Math.PI / 180) * val

    End Function

End Class