>I think you can replace 4*((4*atn(1/5))-(atn(1/239))) by PI()
>
>And if you store the Latitude and Longitude in radians, then it becomes
>

>SET XAxis = cos([TABLENAME].Latitude) * cos([TABLENAME].Longitude)
>
>
>likewise
>SET YAxis = cos([TABLENAME].Latitude) * sin([TABLENAME].Longitude)
>SET ZAxis = sin([TABLENAME].Latitude)
>
>

Thanks

I just want to verify that part. My code to replace those values are as follow:

UPDATE test SET XAxis = (cos(((PI())/180)*Latitude)*cos(((PI())/180)*Longitude))
UPDATE test SET XAxis = (cos(((PI())/180)*Latitude)*sin(((PI())/180)*Longitude))
UPDATE test SET ZAxis = (sin(((PI())/180)*Latitude))

Then, applying the related code would give the image attached:

declare @CenterLat float=47.7795
declare @CenterLon float=-65.7191
declare @EarthRadius float=6371 
declare @SearchDistance float=10000

declare @CntXAxis float
declare @CntYAxis float
declare @CntZAxis float

set @CntXAxis = cos(radians(@CenterLat)) * cos(radians(@CenterLon))
set @CntYAxis = cos(radians(@CenterLat)) * sin(radians(@CenterLon))
set @CntZAxis = sin(radians(@CenterLat))

select *,  ProxDistance = @EarthRadius * acos( XAxis*@CntXAxis + YAxis*@CntYAxis + ZAxis*@CntZAxis)
from test
where  @EarthRadius * acos( XAxis*@CntXAxis + YAxis*@CntYAxis + ZAxis*@CntZAxis) <= @SearchDistance
order by ProxDistance ASC

The code works, but the distance calculated is enormous. There is only about 12 to 16 km between those two coordinates.