Я боролся с этим некоторое время.
У меня было много точек на север / восток в OSGB36, которые нужно регулярно конвертировать на лету.
Обратите внимание, что приведенный ниже UDF преобразует север / восток в проекции OSGB36 (Ordnance Survey) в широту / долготу в проекции WGS84, чтобы их можно было использовать в Картах Google.
/****** Object: UserDefinedFunction [dbo].[NEtoLL] Script Date: 09/06/2012 17:06:39 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE FUNCTION [dbo].[NEtoLL] (@East INT, @North INT, @LatOrLng VARCHAR(3)) RETURNS FLOAT AS
BEGIN
--Author: Sandy Motteram
--Date: 06 September 2012
--UDF adapted from javascript at http://www.bdcc.co.uk/LatLngToOSGB.js
--found on page http://mapki.com/wiki/Tools:Snippets
--Instructions:
--Latitude and Longitude are calculated based on BOTH the easting and northing values from the OSGB36
--This UDF takes both easting and northing values in OSGB36 projection and you must specify if a latitude or longitude co-ordinate should be returned.
--IT first converts E/N values to lat and long in OSGB36 projection, then converts those values to lat/lng in WGS84 projection
--Sample values below
--DECLARE @East INT, @North INT, @LatOrLng VARCHAR(3)
--SELECT @East = 529000, @North = 183650 --that combo should be the corner of Camden High St and Delancey St
DECLARE @Pi FLOAT
, @K0 FLOAT
, @OriginLat FLOAT
, @OriginLong FLOAT
, @OriginX FLOAT
, @OriginY FLOAT
, @a FLOAT
, @b FLOAT
, @e2 FLOAT
, @ex FLOAT
, @n1 FLOAT
, @n2 FLOAT
, @n3 FLOAT
, @OriginNorthings FLOAT
, @lat FLOAT
, @lon FLOAT
, @Northing FLOAT
, @Easting FLOAT
SELECT @Pi = 3.14159265358979323846
, @K0 = 0.9996012717 -- grid scale factor on central meridean
, @OriginLat = 49.0
, @OriginLong = -2.0
, @OriginX = 400000 -- 400 kM
, @OriginY = -100000 -- 100 kM
, @a = 6377563.396 -- Airy Spheroid
, @b = 6356256.910
/* , @e2
, @ex
, @n1
, @n2
, @n3
, @OriginNorthings*/
-- compute interim values
SELECT @a = @a * @K0
, @b = @b * @K0
SET @n1 = (@a - @b) / (@a + @b)
SET @n2 = @n1 * @n1
SET @n3 = @n2 * @n1
SET @lat = @OriginLat * @Pi / 180.0 -- to radians
SELECT @e2 = (@a * @a - @b * @b) / (@a * @a) -- first eccentricity
, @ex = (@a * @a - @b * @b) / (@b * @b) -- second eccentricity
SET @OriginNorthings = @b * @lat + @b * (@n1 * (1.0 + 5.0 * @n1 * (1.0 + @n1) / 4.0) * @lat
- 3.0 * @n1 * (1.0 + @n1 * (1.0 + 7.0 * @n1 / 8.0)) * SIN(@lat) * COS(@lat)
+ (15.0 * @n1 * (@n1 + @n2) / 8.0) * SIN(2.0 * @lat) * COS(2.0 * @lat)
- (35.0 * @n3 / 24.0) * SIN(3.0 * @lat) * COS(3.0 * @lat))
SELECT @northing = @north - @OriginY
, @easting = @east - @OriginX
DECLARE @nu FLOAT
, @phid FLOAT
, @phid2 FLOAT
, @t2 FLOAT
, @t FLOAT
, @q2 FLOAT
, @c FLOAT
, @s FLOAT
, @nphid FLOAT
, @dnphid FLOAT
, @nu2 FLOAT
, @nudivrho FLOAT
, @invnurho FLOAT
, @rho FLOAT
, @eta2 FLOAT
/* Evaluate M term: latitude of the northing on the centre meridian */
SET @northing = @northing + @OriginNorthings
SET @phid = @northing / (@b*(1.0 + @n1 + 5.0 * (@n2 + @n3) / 4.0)) - 1.0
SET @phid2 = @phid + 1.0
WHILE (ABS(@phid2 - @phid) > 0.000001)
BEGIN
SET @phid = @phid2;
SET @nphid = @b * @phid + @b * (@n1 * (1.0 + 5.0 * @n1 * (1.0 + @n1) / 4.0) * @phid
- 3.0 * @n1 * (1.0 + @n1 * (1.0 + 7.0 * @n1 / 8.0)) * SIN(@phid) * COS(@phid)
+ (15.0 * @n1 * (@n1 + @n2) / 8.0) * SIN(2.0 * @phid) * COS(2.0 * @phid)
- (35.0 * @n3 / 24.0) * SIN(3.0 * @phid) * COS(3.0 * @phid))
SET @dnphid = @b * ((1.0 + @n1 + 5.0 * (@n2 + @n3) / 4.0) - 3.0 * (@n1 + @n2 + 7.0 * @n3 / 8.0) * COS(2.0 * @phid)
+ (15.0 * (@n2 + @n3) / 4.0) * COS(4 * @phid) - (35.0 * @n3 / 8.0) * COS(6.0 * @phid))
SET @phid2 = @phid - (@nphid - @northing) / @dnphid
END
SELECT @c = COS(@phid)
, @s = SIN(@phid)
, @t = TAN(@phid)
SELECT @t2 = @t * @t
, @q2 = @easting * @easting
SET @nu2 = (@a * @a) / (1.0 - @e2 * @s * @s)
SET @nu = SQRT(@nu2)
SET @nudivrho = @a * @a * @c * @c / (@b * @b) - @c * @c + 1.0
SET @eta2 = @nudivrho - 1
SET @rho = @nu / @nudivrho;
SET @invnurho = ((1.0 - @e2 * @s * @s) * (1.0 - @e2 * @s * @s)) / (@a * @a * (1.0 - @e2))
SET @lat = @phid - @t * @q2 * @invnurho / 2.0 + (@q2 * @q2 * (@t / (24 * @rho * @nu2 * @nu) * (5 + (3 * @t2) + @eta2 - (9 * @t2 * @eta2))))
SET @lon = (@easting / (@c * @nu))
- (@easting * @q2 * ((@nudivrho + 2.0 * @t2) / (6.0 * @nu2)) / (@c * @nu))
+ (@q2 * @q2 * @easting * (5 + (28 * @t2) + (24 * @t2 * @t2)) / (120 * @nu2 * @nu2 * @nu * @c))
SELECT @lat = @lat * 180.0 / @Pi
, @lon = @lon * 180.0 / @Pi + @OriginLong
--Now convert the lat and long from OSGB36 to WGS84
DECLARE @OGlat FLOAT
, @OGlon FLOAT
, @height FLOAT
SELECT @OGlat = @lat
, @OGlon = @lon
, @height = 24 --London's mean height above sea level is 24 metres. Adjust for other locations.
DECLARE @deg2rad FLOAT
, @rad2deg FLOAT
, @radOGlat FLOAT
, @radOGlon FLOAT
SELECT @deg2rad = @Pi / 180
, @rad2deg = 180 / @Pi
--first off convert to radians
SELECT @radOGlat = @OGlat * @deg2rad
, @radOGlon = @OGlon * @deg2rad
--these are the values for WGS84(GRS80) to OSGB36(Airy)
DECLARE @a2 FLOAT
, @h FLOAT
, @xp FLOAT
, @yp FLOAT
, @zp FLOAT
, @xr FLOAT
, @yr FLOAT
, @zr FLOAT
, @sf FLOAT
, @e FLOAT
, @v FLOAT
, @x FLOAT
, @y FLOAT
, @z FLOAT
, @xrot FLOAT
, @yrot FLOAT
, @zrot FLOAT
, @hx FLOAT
, @hy FLOAT
, @hz FLOAT
, @newLon FLOAT
, @newLat FLOAT
, @p FLOAT
, @errvalue FLOAT
, @lat0 FLOAT
SELECT @a2 = 6378137 -- WGS84_AXIS
, @e2 = 0.00669438037928458 -- WGS84_ECCENTRIC
, @h = @height -- height above datum (from $GPGGA sentence)
, @a = 6377563.396 -- OSGB_AXIS
, @e = 0.0066705397616 -- OSGB_ECCENTRIC
, @xp = 446.448
, @yp = -125.157
, @zp = 542.06
, @xr = 0.1502
, @yr = 0.247
, @zr = 0.8421
, @s = -20.4894
-- convert to cartesian; lat, lon are in radians
SET @sf = @s * 0.000001
SET @v = @a / (sqrt(1 - (@e * (SIN(@radOGlat) * SIN(@radOGlat)))))
SET @x = (@v + @h) * COS(@radOGlat) * COS(@radOGlon)
SET @y = (@v + @h) * COS(@radOGlat) * SIN(@radOGlon)
SET @z = ((1 - @e) * @v + @h) * SIN(@radOGlat)
-- transform cartesian
SET @xrot = (@xr / 3600) * @deg2rad
SET @yrot = (@yr / 3600) * @deg2rad
SET @zrot = (@zr / 3600) * @deg2rad
SET @hx = @x + (@x * @sf) - (@y * @zrot) + (@z * @yrot) + @xp
SET @hy = (@x * @zrot) + @y + (@y * @sf) - (@z * @xrot) + @yp
SET @hz = (-1 * @x * @yrot) + (@y * @xrot) + @z + (@z * @sf) + @zp
-- Convert back to lat, lon
SET @newLon = ATAN(@hy / @hx)
SET @p = SQRT((@hx * @hx) + (@hy * @hy))
SET @newLat = ATAN(@hz / (@p * (1 - @e2)))
SET @v = @a2 / (SQRT(1 - @e2 * (SIN(@newLat) * SIN(@newLat))))
SET @errvalue = 1.0;
SET @lat0 = 0
WHILE (@errvalue > 0.001)
BEGIN
SET @lat0 = ATAN((@hz + @e2 * @v * SIN(@newLat)) / @p)
SET @errvalue = ABS(@lat0 - @newLat)
SET @newLat = @lat0
END
--convert back to degrees
SET @newLat = @newLat * @rad2deg
SET @newLon = @newLon * @rad2deg
DECLARE @ReturnMe FLOAT
SET @ReturnMe = 0
IF @LatOrLng = 'Lat'
SET @ReturnMe = @newLat
IF @LatOrLng = 'Lng'
SET @ReturnMe = @newLon
RETURN @ReturnMe
END
GO