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Sweref99 to WGS84 conversion in javascript test
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// Author: Arnold Andreasson, info@mellifica.se | |
// Copyright (c) 2007-2016 Arnold Andreasson | |
// License: MIT License as follows: | |
// | |
// Permission is hereby granted, free of charge, to any person obtaining a copy | |
// of this software and associated documentation files (the "Software"), to deal | |
// in the Software without restriction, including without limitation the rights | |
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
// copies of the Software, and to permit persons to whom the Software is | |
// furnished to do so, subject to the following conditions: | |
// | |
// The above copyright notice and this permission notice shall be included in | |
// all copies or substantial portions of the Software. | |
// | |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
// THE SOFTWARE. | |
// ============================================================================= | |
// Javascript-implementation of "Gauss Conformal Projection | |
// (Transverse Mercator), Krügers Formulas". | |
// - Parameters for SWEREF99 lat-long to/from RT90 and SWEREF99 | |
// coordinates (RT90 and SWEREF99 are used in Swedish maps). | |
// Source: http://www.lantmateriet.se/geodesi/ | |
var axis = null; // Semi-major axis of the ellipsoid. | |
var flattening = null; // Flattening of the ellipsoid. | |
var central_meridian = null; // Central meridian for the projection. | |
var lat_of_origin = null; // Latitude of origin. | |
var scale = null; // Scale on central meridian. | |
var false_northing = null; // Offset for origo. | |
var false_easting = null; // Offset for origo. | |
// Parameters for RT90 and SWEREF99TM. | |
// Note: Parameters for RT90 are choosen to eliminate the | |
// differences between Bessel and GRS80-ellipsoides. | |
// Bessel-variants should only be used if lat/long are given as | |
// RT90-lat/long based on the Bessel ellipsoide (from old maps). | |
// Parameter: projection (string). Must match if-statement. | |
function swedish_params(projection) { | |
// RT90 parameters, GRS 80 ellipsoid. | |
if (projection == "rt90_7.5_gon_v") { | |
grs80_params(); | |
central_meridian = 11.0 + 18.375/60.0; | |
scale = 1.000006000000; | |
false_northing = -667.282; | |
false_easting = 1500025.141; | |
} | |
else if (projection == "rt90_5.0_gon_v") { | |
grs80_params(); | |
central_meridian = 13.0 + 33.376/60.0; | |
scale = 1.000005800000; | |
false_northing = -667.130; | |
false_easting = 1500044.695; | |
} | |
else if (projection == "rt90_2.5_gon_v") { | |
grs80_params(); | |
central_meridian = 15.0 + 48.0/60.0 + 22.624306/3600.0; | |
scale = 1.00000561024; | |
false_northing = -667.711; | |
false_easting = 1500064.274; | |
} | |
else if (projection == "rt90_0.0_gon_v") { | |
grs80_params(); | |
central_meridian = 18.0 + 3.378/60.0; | |
scale = 1.000005400000; | |
false_northing = -668.844; | |
false_easting = 1500083.521; | |
} | |
else if (projection == "rt90_2.5_gon_o") { | |
grs80_params(); | |
central_meridian = 20.0 + 18.379/60.0; | |
scale = 1.000005200000; | |
false_northing = -670.706; | |
false_easting = 1500102.765; | |
} | |
else if (projection == "rt90_5.0_gon_o") { | |
grs80_params(); | |
central_meridian = 22.0 + 33.380/60.0; | |
scale = 1.000004900000; | |
false_northing = -672.557; | |
false_easting = 1500121.846; | |
} | |
// RT90 parameters, Bessel 1841 ellipsoid. | |
else if (projection == "bessel_rt90_7.5_gon_v") { | |
bessel_params(); | |
central_meridian = 11.0 + 18.0/60.0 + 29.8/3600.0; | |
} | |
else if (projection == "bessel_rt90_5.0_gon_v") { | |
bessel_params(); | |
central_meridian = 13.0 + 33.0/60.0 + 29.8/3600.0; | |
} | |
else if (projection == "bessel_rt90_2.5_gon_v") { | |
bessel_params(); | |
central_meridian = 15.0 + 48.0/60.0 + 29.8/3600.0; | |
} | |
else if (projection == "bessel_rt90_0.0_gon_v") { | |
bessel_params(); | |
central_meridian = 18.0 + 3.0/60.0 + 29.8/3600.0; | |
} | |
else if (projection == "bessel_rt90_2.5_gon_o") { | |
bessel_params(); | |
central_meridian = 20.0 + 18.0/60.0 + 29.8/3600.0; | |
} | |
else if (projection == "bessel_rt90_5.0_gon_o") { | |
bessel_params(); | |
central_meridian = 22.0 + 33.0/60.0 + 29.8/3600.0; | |
} | |
// SWEREF99TM and SWEREF99ddmm parameters. | |
else if (projection == "sweref_99_tm") { | |
sweref99_params(); | |
central_meridian = 15.00; | |
lat_of_origin = 0.0; | |
scale = 0.9996; | |
false_northing = 0.0; | |
false_easting = 500000.0; | |
} | |
else if (projection == "sweref_99_1200") { | |
sweref99_params(); | |
central_meridian = 12.00; | |
} | |
else if (projection == "sweref_99_1330") { | |
sweref99_params(); | |
central_meridian = 13.50; | |
} | |
else if (projection == "sweref_99_1500") { | |
sweref99_params(); | |
central_meridian = 15.00; | |
} | |
else if (projection == "sweref_99_1630") { | |
sweref99_params(); | |
central_meridian = 16.50; | |
} | |
else if (projection == "sweref_99_1800") { | |
sweref99_params(); | |
central_meridian = 18.00; | |
} | |
else if (projection == "sweref_99_1415") { | |
sweref99_params(); | |
central_meridian = 14.25; | |
} | |
else if (projection == "sweref_99_1545") { | |
sweref99_params(); | |
central_meridian = 15.75; | |
} | |
else if (projection == "sweref_99_1715") { | |
sweref99_params(); | |
central_meridian = 17.25; | |
} | |
else if (projection == "sweref_99_1845") { | |
sweref99_params(); | |
central_meridian = 18.75; | |
} | |
else if (projection == "sweref_99_2015") { | |
sweref99_params(); | |
central_meridian = 20.25; | |
} | |
else if (projection == "sweref_99_2145") { | |
sweref99_params(); | |
central_meridian = 21.75; | |
} | |
else if (projection == "sweref_99_2315") { | |
sweref99_params(); | |
central_meridian = 23.25; | |
} | |
// Test-case: | |
// Lat: 66 0'0", lon: 24 0'0". | |
// X:1135809.413803 Y:555304.016555. | |
else if (projection == "test_case") { | |
axis = 6378137.0; | |
flattening = 1.0 / 298.257222101; | |
central_meridian = 13.0 + 35.0/60.0 + 7.692000/3600.0; | |
lat_of_origin = 0.0; | |
scale = 1.000002540000; | |
false_northing = -6226307.8640; | |
false_easting = 84182.8790; | |
// Not a valid projection. | |
} else { | |
central_meridian = null; | |
} | |
} | |
// Sets of default parameters. | |
function grs80_params() { | |
axis = 6378137.0; // GRS 80. | |
flattening = 1.0 / 298.257222101; // GRS 80. | |
central_meridian = null; | |
lat_of_origin = 0.0; | |
} | |
function bessel_params() { | |
axis = 6377397.155; // Bessel 1841. | |
flattening = 1.0 / 299.1528128; // Bessel 1841. | |
central_meridian = null; | |
lat_of_origin = 0.0; | |
scale = 1.0; | |
false_northing = 0.0; | |
false_easting = 1500000.0; | |
} | |
function sweref99_params() { | |
axis = 6378137.0; // GRS 80. | |
flattening = 1.0 / 298.257222101; // GRS 80. | |
central_meridian = null; | |
lat_of_origin = 0.0; | |
scale = 1.0; | |
false_northing = 0.0; | |
false_easting = 150000.0; | |
} | |
// Conversion from geodetic coordinates to grid coordinates. | |
function geodetic_to_grid(latitude, longitude) { | |
var x_y = new Array(2); | |
if (central_meridian == null) { | |
return x_y; | |
} | |
// Prepare ellipsoid-based stuff. | |
var e2 = flattening * (2.0 - flattening); | |
var n = flattening / (2.0 - flattening); | |
var a_roof = axis / (1.0 + n) * (1.0 + n*n/4.0 + n*n*n*n/64.0); | |
var A = e2; | |
var B = (5.0*e2*e2 - e2*e2*e2) / 6.0; | |
var C = (104.0*e2*e2*e2 - 45.0*e2*e2*e2*e2) / 120.0; | |
var D = (1237.0*e2*e2*e2*e2) / 1260.0; | |
var beta1 = n/2.0 - 2.0*n*n/3.0 + 5.0*n*n*n/16.0 + 41.0*n*n*n*n/180.0; | |
var beta2 = 13.0*n*n/48.0 - 3.0*n*n*n/5.0 + 557.0*n*n*n*n/1440.0; | |
var beta3 = 61.0*n*n*n/240.0 - 103.0*n*n*n*n/140.0; | |
var beta4 = 49561.0*n*n*n*n/161280.0; | |
// Convert. | |
var deg_to_rad = Math.PI / 180.0; | |
var phi = latitude * deg_to_rad; | |
var lambda = longitude * deg_to_rad; | |
var lambda_zero = central_meridian * deg_to_rad; | |
var phi_star = phi - Math.sin(phi) * Math.cos(phi) * (A + | |
B*Math.pow(Math.sin(phi), 2) + | |
C*Math.pow(Math.sin(phi), 4) + | |
D*Math.pow(Math.sin(phi), 6)); | |
var delta_lambda = lambda - lambda_zero; | |
var xi_prim = Math.atan(Math.tan(phi_star) / Math.cos(delta_lambda)); | |
var eta_prim = math_atanh(Math.cos(phi_star) * Math.sin(delta_lambda)); | |
var x = scale * a_roof * (xi_prim + | |
beta1 * Math.sin(2.0*xi_prim) * math_cosh(2.0*eta_prim) + | |
beta2 * Math.sin(4.0*xi_prim) * math_cosh(4.0*eta_prim) + | |
beta3 * Math.sin(6.0*xi_prim) * math_cosh(6.0*eta_prim) + | |
beta4 * Math.sin(8.0*xi_prim) * math_cosh(8.0*eta_prim)) + | |
false_northing; | |
var y = scale * a_roof * (eta_prim + | |
beta1 * Math.cos(2.0*xi_prim) * math_sinh(2.0*eta_prim) + | |
beta2 * Math.cos(4.0*xi_prim) * math_sinh(4.0*eta_prim) + | |
beta3 * Math.cos(6.0*xi_prim) * math_sinh(6.0*eta_prim) + | |
beta4 * Math.cos(8.0*xi_prim) * math_sinh(8.0*eta_prim)) + | |
false_easting; | |
x_y[0] = Math.round(x * 1000.0) / 1000.0; | |
x_y[1] = Math.round(y * 1000.0) / 1000.0; | |
// x_y[0] = x; | |
// x_y[1] = y; | |
return x_y; | |
} | |
// Conversion from grid coordinates to geodetic coordinates. | |
function grid_to_geodetic(x, y) { | |
var lat_lon = new Array(2); | |
if (central_meridian == null) { | |
return lat_lon; | |
} | |
// Prepare ellipsoid-based stuff. | |
var e2 = flattening * (2.0 - flattening); | |
var n = flattening / (2.0 - flattening); | |
var a_roof = axis / (1.0 + n) * (1.0 + n*n/4.0 + n*n*n*n/64.0); | |
var delta1 = n/2.0 - 2.0*n*n/3.0 + 37.0*n*n*n/96.0 - n*n*n*n/360.0; | |
var delta2 = n*n/48.0 + n*n*n/15.0 - 437.0*n*n*n*n/1440.0; | |
var delta3 = 17.0*n*n*n/480.0 - 37*n*n*n*n/840.0; | |
var delta4 = 4397.0*n*n*n*n/161280.0; | |
var Astar = e2 + e2*e2 + e2*e2*e2 + e2*e2*e2*e2; | |
var Bstar = -(7.0*e2*e2 + 17.0*e2*e2*e2 + 30.0*e2*e2*e2*e2) / 6.0; | |
var Cstar = (224.0*e2*e2*e2 + 889.0*e2*e2*e2*e2) / 120.0; | |
var Dstar = -(4279.0*e2*e2*e2*e2) / 1260.0; | |
// Convert. | |
var deg_to_rad = Math.PI / 180; | |
var lambda_zero = central_meridian * deg_to_rad; | |
var xi = (x - false_northing) / (scale * a_roof); | |
var eta = (y - false_easting) / (scale * a_roof); | |
var xi_prim = xi - | |
delta1*Math.sin(2.0*xi) * math_cosh(2.0*eta) - | |
delta2*Math.sin(4.0*xi) * math_cosh(4.0*eta) - | |
delta3*Math.sin(6.0*xi) * math_cosh(6.0*eta) - | |
delta4*Math.sin(8.0*xi) * math_cosh(8.0*eta); | |
var eta_prim = eta - | |
delta1*Math.cos(2.0*xi) * math_sinh(2.0*eta) - | |
delta2*Math.cos(4.0*xi) * math_sinh(4.0*eta) - | |
delta3*Math.cos(6.0*xi) * math_sinh(6.0*eta) - | |
delta4*Math.cos(8.0*xi) * math_sinh(8.0*eta); | |
var phi_star = Math.asin(Math.sin(xi_prim) / math_cosh(eta_prim)); | |
var delta_lambda = Math.atan(math_sinh(eta_prim) / Math.cos(xi_prim)); | |
var lon_radian = lambda_zero + delta_lambda; | |
var lat_radian = phi_star + Math.sin(phi_star) * Math.cos(phi_star) * | |
(Astar + | |
Bstar*Math.pow(Math.sin(phi_star), 2) + | |
Cstar*Math.pow(Math.sin(phi_star), 4) + | |
Dstar*Math.pow(Math.sin(phi_star), 6)); | |
lat_lon[0] = lat_radian * 180.0 / Math.PI; | |
lat_lon[1] = lon_radian * 180.0 / Math.PI; | |
return lat_lon; | |
} | |
// Missing functions in the Math library. | |
function math_sinh(value) { | |
return 0.5 * (Math.exp(value) - Math.exp(-value)); | |
} | |
function math_cosh(value) { | |
return 0.5 * (Math.exp(value) + Math.exp(-value)); | |
} | |
function math_atanh(value) { | |
return 0.5 * Math.log((1.0 + value) / (1.0 - value)); | |
} | |
### TEST | |
var inarr = [[6402040,328169], | |
[6401681,327833], | |
[6401696,327830], | |
[6401692,327812], | |
[6401678,327807], | |
[6401656,327837], | |
[6401645,327819], | |
[6401638,327788], | |
[6401603,327783], | |
[6401594,327775], | |
[6401549,327852], | |
[6401537,327845], | |
[6401520,327841], | |
[6401508,327843], | |
[6401493,327831], | |
[6401484,327824], | |
[6401464,327824], | |
[6401469,327798], | |
[6401465,327791], | |
[6401457,327782], | |
[6401447,327774], | |
[6401436,327768], | |
[6401434,327759], | |
[6401429,327745], | |
[6401421,327730], | |
[6401430,327717], | |
[6401439,327686], | |
[6401476,327690], | |
[6401504,327666], | |
[6400481,326707], | |
[6400482,327209], | |
[6399348,327471], | |
[6398991,328052], | |
[6398871,328525], | |
[6398901,328570], | |
[6398936,328567], | |
[6398952,328611], | |
[6398925,328679], | |
[6398968,328665], | |
[6398984,328695], | |
[6398960,328721], | |
[6398986,328761], | |
[6399000,328783], | |
[6399013,328824], | |
[6399016,328823], | |
[6399133,328728], | |
[6399155,328732], | |
[6399161,328744], | |
[6399262,328714], | |
[6399288,328708], | |
[6399374,328701]] | |
swedish_params("sweref_99_tm"); | |
inarr.forEach(function(o,i){ | |
console.log(grid_to_geodetic(o[0],o[1])) ; | |
}); |
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