1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
/**
* OpenLayers Swiss (CH1903+/LV95) grid projection transformations
*
* Provides transform functions for WGS84<->CH1903+ projections.
*
* Maths courtesy of the Swiss Federal Office of Topography:
* http://www.swisstopo.admin.ch/internet/swisstopo/en/home/products/software/products/skripts.html
* Simplifed a bit, and with x/y swapped the normal way round.
*/
// Use the same calcs as CH1903 but with offset.
// Maximum distortion is 3M which should be sufficient for our purposes.
var LV95_X_OFFSET = 2000000;
var LV95_Y_OFFSET = 1000000;
OpenLayers.Projection.CH1903Plus = {
// Convert WGS lat/long (° dec) to CH x
WGStoCHx: function(lat, lng) {
// Converts degrees dec to seconds
lat = lat * 3600;
lng = lng * 3600;
// Auxiliary values (% Bern)
var lat_aux = (lat - 169028.66) / 10000;
var lng_aux = (lng - 26782.5) / 10000;
// Process X
var x = 600072.37 + LV95_X_OFFSET;
x = x + (211455.93 * lng_aux);
x = x - (10938.51 * lng_aux * lat_aux);
x = x - (0.36 * lng_aux * Math.pow(lat_aux, 2));
x = x - (44.54 * Math.pow(lng_aux, 3));
return x;
},
// Convert WGS lat/long (° dec) to CH y
WGStoCHy: function(lat, lng) {
// Converts degrees dec to seconds
lat = lat * 3600;
lng = lng * 3600;
// Auxiliary values (% Bern)
var lat_aux = (lat - 169028.66)/10000;
var lng_aux = (lng - 26782.5)/10000;
// Process Y
var y = 200147.07 + LV95_Y_OFFSET;
y = y + (308807.95 * lat_aux);
y = y + (3745.25 * Math.pow(lng_aux, 2));
y = y + (76.63 * Math.pow(lat_aux, 2));
y = y - (194.56 * Math.pow(lng_aux, 2) * lat_aux);
y = y + (119.79 * Math.pow(lat_aux, 3));
return y;
},
// Convert CH x/y to WGS lat
chToWGSlat: function(x, y) {
// Converts militar to civil and to unit = 1000km
// Axiliary values (% Bern)
var x_aux = (x - 600000 - LV95_X_OFFSET) / 1000000;
var y_aux = (y - 200000 - LV95_Y_OFFSET) / 1000000;
// Process lat
var lat = 16.9023892;
lat = lat + (3.238272 * y_aux);
lat = lat - (0.270978 * Math.pow(x_aux, 2));
lat = lat - (0.002528 * Math.pow(y_aux, 2));
lat = lat - (0.0447 * Math.pow(x_aux, 2) * y_aux);
lat = lat - (0.0140 * Math.pow(y_aux, 3));
// Unit 10000" to 1 " and converts seconds to degrees (dec)
lat = lat * 100 / 36;
return lat;
},
// Convert CH x/y to WGS long
chToWGSlng: function(x, y) {
// Converts militar to civil and to unit = 1000km
// Axiliary values (% Bern)
var x_aux = (x - 600000 - LV95_X_OFFSET) / 1000000;
var y_aux = (y - 200000 - LV95_Y_OFFSET) / 1000000;
// Process long
var lng = 2.6779094;
lng = lng + (4.728982 * x_aux);
lng = lng + (0.791484 * x_aux * y_aux);
lng = lng + (0.1306 * x_aux * Math.pow(y_aux, 2));
lng = lng - (0.0436 * Math.pow(x_aux, 3));
// Unit 10000" to 1 " and converts seconds to degrees (dec)
lng = lng * 100 / 36;
return lng;
},
// Function to convert a WGS84 coordinate to a Swiss coordinate.
projectForwardSwiss: function(point) {
var x = OpenLayers.Projection.CH1903Plus.WGStoCHx(point.y, point.x),
y = OpenLayers.Projection.CH1903Plus.WGStoCHy(point.y, point.x);
point.x = x;
point.y = y;
return point;
},
// Function to convert a Swiss coordinate to a WGS84 coordinate.
projectInverseSwiss: function(point) {
var lon = OpenLayers.Projection.CH1903Plus.chToWGSlng(point.x, point.y);
var lat = OpenLayers.Projection.CH1903Plus.chToWGSlat(point.x, point.y);
point.x = lon;
point.y = lat;
return point;
}
};
/**
* Note: One transform declared
* Transforms from EPSG:4326 to EPSG:2056
*/
OpenLayers.Projection.addTransform("EPSG:4326", "EPSG:2056",
OpenLayers.Projection.CH1903Plus.projectForwardSwiss);
OpenLayers.Projection.addTransform("EPSG:2056", "EPSG:4326",
OpenLayers.Projection.CH1903Plus.projectInverseSwiss);
|