Distance between two points using latitude and longitude,

I've spent several days trying to figure this out and can't pinpoint the problems exactly. I have a SQL 2005 database storing latitude and longitude as Decimal (18,8), all of which I got by going to Google.

For these two locations: From: 10715 Downsville Pike Ste 100 MD 21740 to: 444 East College Ave Ste 120 State College PA, 16801

Taking into account that the distance will be "like a crow", my results still remain. In this example, my result says 21.32 miles, but Google Maps says 144 miles.

I think a defeat that makes it even more frustrating, I found this site: http://jan.ucc.nau.edu/~cvm/latlongdist.html and came up with almost the same results as me.

Here's my functions and request:

Functions: CalculateDistance

DECLARE @Temp FLOAT

SET @Temp = SIN(@Latitude1/57.2957795130823) * 
    SIN(@Latitude2/57.2957795130823) + 
    COS(@Latitude1/57.2957795130823) * COS(@Latitude2/57.2957795130823) * 
    COS(@Longitude2/57.2957795130823 - @Longitude1/57.2957795130823)

IF @Temp > 1
    SET @Temp = 1
ELSE IF @Temp < -1
    SET @Temp = -1

RETURN (3958.75586574 * ACOS(@Temp) )

      

        
        
        
      

    

LatitudePlusDistance

RETURN (SELECT @StartLatitude + SQRT(@Distance * @Distance / 4766.8999155991))

      

        
        
        
      

    

LongitudePlusDistance

RETURN (SELECT @StartLongitude + SQRT(@Distance * @Distance / 
    (4784.39411916406 * 
    COS(2 * @StartLatitude / 114.591559026165) * 
    COS(2 * @StartLatitude / 114.591559026165))))

      

        
        
        
      

    

Query:

DECLARE @Longitude DECIMAL(18,8),
        @Latitude DECIMAL(18,8),
        @MinLongitude DECIMAL(18,8),
        @MaxLongitude DECIMAL(18,8),
        @MinLatitude DECIMAL(18,8),
        @MaxLatitude DECIMAL(18,8),
        @WithinMiles DECIMAL(2)

Set @Latitude = -77.856052
Set @Longitude = 40.799159
Set @WithinMiles = 50

-- Calculate the Max Lat/Long
SELECT @MaxLongitude = dbo.LongitudePlusDistance(@Longitude, @Latitude, 
           @WithinMiles),
       @MaxLatitude = dbo.LatitudePlusDistance(@Latitude, @WithinMiles)

-- Calculate the min lat/long
SELECT @MinLatitude = 2 * @Latitude - @MaxLatitude,
       @MinLongitude = 2 * @Longitude - @MaxLongitude

SELECT Top 20 *, dbo.CalculateDistance(@Longitude, @Latitude, 
    LocationLongitude, LocationLatitude) as 'Distance'
FROM   Location
WHERE  LocationLongitude Between @MinLongitude And @MaxLongitude
       And LocationLatitude Between @MinLatitude And @MaxLatitude
       And dbo.CalculateDistance(@Longitude, @Latitude, LocationLongitude, 
           LocationLatitude) <= @WithinMiles
ORDER BY dbo.CalculateDistance(@Longitude, @Latitude, LocationLongitude, 
    LocationLatitude)