Module:Ordnance Survey coordinates/sandbox: Difference between revisions

Revision as of 04:47, 16 December 2023

Revision as of 05:28, 16 December 2023

Line 54:

local wgs84radius = 6378137.0

local wgs84ecc = 0.00669438003551279089034150031998869922791

local scaleUKscaleGB = 0.9996012717

local eastingGB = 400000.0

local northingGB = -100000.0

local lat0GB = 49.0

local lon0GB = -2.0

local Airyradius = 6377563.396

local Airyecc = 0.006670539761597529073698869358812557054558

local function northeast(lett,num,shift)

Line 92 ⟶ 98:

local function GBEN2LL(e,n)

-- True Origin is 2 deg W

local phi0uk=-2.0lon0GB

-- True Origin is 49 deg N

local lambda0uk=49.0lat0GB

-- scale factor @ central meridian

local F0uk=scaleUKscaleGB

-- True origin in 400 km E of false origin

local E0uk=400000.0eastingGB

--True origin is 100 km S of false origin

local N0uk=-100000.0northingGB

-- semi-major axis (in line to equator) 0.996012717 is yer scale @ central meridian

local auk=6377563.396Airyradius*F0uk

--semi-minor axis (in line to poles)

local buk=6356256.91*F0uk

Line 108 ⟶ 114:

local n1uk=0.00167322025032508731869331280635710896296

-- first eccentricity squared=2*f-f^2where f=(a1-b1)/a1

local e2uk=0.006670539761597529073698869358812557054558Airyecc

local k=(n-N0uk)/auk+lambda0uk/dr

local nextcounter=0

Line 138 ⟶ 144:

local long=phi0uk+dr*(y1*j6-y1*y1*y1*j7+pow(y1,5.0)*j8-pow(y1,7.0)*j9)

local lat=k9*dr

local v=6377563.396Airyradius/sqrt(1.0-e2uk*pow(sin(k),2.0))

local cartxa=v*cos(k9)*cos(long/dr)

local cartya=v*cos(k9)*sin(long/dr)

Line 486 ⟶ 492:

local b1 = 6356752.3141

local a2 = 6377563.396Airyradius

local b2 = 6356256.910

Line 551 ⟶ 557:

end

--[[

* Convert latitude, longitude in decimal degrees to

* OSBG36 Easting and Northing

]]

local function LatLon2OSGB36( latlon )

local latitude = latlon.lat

local longitude = latlon.lon

-- Airy 1830 ellipsoid

local radius = Airyradius

-- inverse flattening 1/f: 299.3249647

local eccentricity = Airyecc -- square of eccentricity

local scale = scaleGB

local easting_offset = eastingGB

local northing_offset = northingGB

local latitude_origin = lat0GB

local longitude_origin = lon0GB

local tm = LatLonOrigin2TM(latitude, longitude, latitude_origin, longitude_origin)

if not tm then return '' end

-- fix by Roger W Haworth

local grid_x = floor( tm.easting / 100000 )

local grid_y = floor( tm.northing / 100000 )

if grid_x < 0 or grid_x > 6 or grid_y < 0 or grid_y > 12 then return '' end

-- 0000000001111111111222222

-- 1234567890123456789012345

local letters = "ABCDEFGHJKLMNOPQRSTUVWXYZ"

local c1 = mw.ustring.sub(letters,18-floor(grid_y/5)*5+floor(grid_x/5),1)

local c2 = mw.ustring.sub(letters,21-(grid_y%5)*5+grid_x%5,1)

local e = mw.ustring.format('%05d', tm.easting%100000)

local n = mw.ustring.format('%05d', tm.northing%100000)

return c1..c2..e..n

end

function oscoord.WGS2OSGB(lat,lon)

return LatLong2OSGB(HelmertDatumShift(lat,lon))

end

return oscoord