谷歌地图离线发布系列之偏移处理（三）纠偏算法

来源：互联网发布：淘宝直通车开通要求编辑：程序博客网时间：2024/05/07 04:50

先上代码，用js实现的纠偏算法：

var pi = 3.14159265358979324;//// Krasovsky 1940//// a = 6378245.0, 1/f = 298.3// b = a * (1 - f)// ee = (a^2 - b^2) / a^2;var a = 6378245.0;var ee = 0.00669342162296594323;function outOfChina(lat, lon){    if (lon < 72.004 || lon > 137.8347)        return 1;    if (lat < 0.8293 || lat > 55.8271)        return 1;    return 0;}function transformLat(x,y){    var ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(x > 0 ? x:-x);    ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 *Math.sin(2.0 * x * pi)) * 2.0 / 3.0;    ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0;    ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;    return ret;}function transformLon(x,y){    var ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(x > 0 ? x:-x);    ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;    ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0;    ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0;    return ret;}function transformFromWGSToGCJ(wgLoc){    var mgLoc ={};    mgLoc.lat = 0;    mgLoc.lng = 0;    if (outOfChina(wgLoc.lat, wgLoc.lng))    {        mgLoc = wgLoc;        return mgLoc;    }    var dLat = transformLat(wgLoc.lng - 105.0, wgLoc.lat - 35.0);    var dLon = transformLon(wgLoc.lng - 105.0, wgLoc.lat - 35.0);    var radLat = wgLoc.lat / 180.0 * pi;    var magic = Math.sin(radLat);    magic = 1 - ee * magic * magic;    var sqrtMagic = Math.sqrt(magic);    dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);    dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);    mgLoc.lat = wgLoc.lat + dLat;    mgLoc.lng = wgLoc.lng + dLon;    return mgLoc;}

参考文章1：http://blog.csdn.net/coolypf/article/details/8686588

WGS-84 到 GCJ-02 的转换（即 GPS 加偏）算法是一个普通青年轻易无法接触到的“公开”的秘密。这个算法的代码在互联网上是公开的，详情请使用 Google 搜索 "wgtochina_lb" 。

整理后的算法代码请参考 https://on4wp7.codeplex.com/SourceControl/changeset/view/21483#353936 。知道了这个算法之后，就可以离线进行 Google 地图偏移校正，不必像之前那么麻烦。

至于 GCJ-02 到 WGS-84 的转换（即 GPS 纠偏），可以使用二分法。

参考文章2：http://www.zuidaima.com/code/file/1665077235663872.htm?dir=/correct_lat_lon/src/com/hgq/correct/MapFix.java

package com.hgq.correct;

003

004

005/**

006 * 经纬度纠偏工具类

007 * [一句话功能简述]<p>

008 * [功能详细描述]<p>

009 * @author PeiYu

010 * @version 1.0, 2012-8-24

011 * @see

012 * @since gframe-v100

013 */

014public class MapFix

015{

016    private double casm_f = 0.0;

017

018    private double casm_rr = 0.0;

019

020    private double casm_t1 = 0.0;

021

022    private double casm_t2 = 0.0;

023

024    private double casm_x1 = 0.0;

025

026    private double casm_x2 = 0.0;

027

028    private double casm_y1 = 0.0;

029

030    private double casm_y2 = 0.0;

031

032    private MapFix()

033    {

034        casm_rr = 0.0;

035        casm_t1 = 0.0;

036        casm_t2 = 0.0;

037        casm_x1 = 0.0;

038        casm_y1 = 0.0;

039        casm_x2 = 0.0;

040        casm_y2 = 0.0;

041        casm_f = 0.0;

042    }

043

044    private static MapFix instance;

045

046    public static MapFix getInstance()

047    {

048        if (instance == null)

049        {

050            instance = new MapFix();

051        }

052        return instance;

053    }

054

055    /**

056     * 纠偏

057     * @param x 经度

058     * @param y 纬度

059     * @return [0]纠偏后经度   [1]纠偏后纬度

060     */

061    public double[] fix(double x , double y)

062    {

063        double[] res = new double[2];

064        try

065        {

066            double num = x * 3686400.0;

067            double num2 = y * 3686400.0;

068            double num3 = 0.0;

069            double num4 = 0.0;

070            double num5 = 0.0;

071            MapPoint point = wgtochina_lb(1, (int) num, (int) num2, (int) num5, (int) num3, (int) num4);

072            double num6 = point.getX();

073            double num7 = point.getY();

074            num6 /= 3686400.0;

075            num7 /= 3686400.0;

076            res[0] = num6;

077            res[1] = num7;

078        }

079        catch (Exception ex)

080        {

081            System.out.println(ex);

082        }

083        return res;

084    }

085

086    private void IniCasm(double w_time , double w_lng , double w_lat)

087    {

088        casm_t1 = w_time;

089        casm_t2 = w_time;

090        double num = (int) (w_time / 0.357);

091        casm_rr = w_time - (num * 0.357);

092        if (w_time == 0.0)

093        {

094            casm_rr = 0.3;

095        }

096        casm_x1 = w_lng;

097        casm_y1 = w_lat;

098        casm_x2 = w_lng;

099        casm_y2 = w_lat;

100        casm_f = 3.0;

101    }

102

103    private double random_yj()

104    {

105        double num = 314159269.0;

106        double num2 = 453806245.0;

107        casm_rr = (num * casm_rr) + num2;

108        double num3 = (int) (casm_rr / 2.0);

109        casm_rr -= num3 * 2.0;

110        casm_rr /= 2.0;

111        return casm_rr;

112    }

113

114    private double Transform_jy5(double x , double xx)

115    {

116        double num = 6378245.0;

117        double num2 = 0.00669342;

118        double num3 = Math.sqrt(1.0 - ((num2 * yj_sin2(x * 0.0174532925199433)) * yj_sin2(x * 0.0174532925199433)));

119        return ((xx * 180.0) / (((num / num3) * Math.cos(x * 0.0174532925199433)) * 3.1415926));

120    }

121

122    private double Transform_jyj5(double x , double yy)

123    {

124        double num = 6378245.0;

125        double num2 = 0.00669342;

126        double d = 1.0 - ((num2 * yj_sin2(x * 0.0174532925199433)) * yj_sin2(x * 0.0174532925199433));

127        double num4 = (num * (1.0 - num2)) / (d * Math.sqrt(d));

128        return ((yy * 180.0) / (num4 * 3.1415926));

129    }

130

131    private double Transform_yj5(double x , double y)

132    {

133        double num = ((((300.0 + (1.0 * x)) + (2.0 * y)) + ((0.1 * x) * x)) + ((0.1 * x) * y))

134                + (0.1 * Math.sqrt(Math.sqrt(x * x)));

135        num += ((20.0 * yj_sin2(18.849555921538762 * x)) + (20.0 * yj_sin2(6.283185307179588* x))) * 0.6667;

136        num += ((20.0 * yj_sin2(3.141592653589794 * x)) + (40.0 * yj_sin2(1.0471975511965981* x))) * 0.6667;

137        return (num + (((150.0 * yj_sin2(0.26179938779914952 * x)) + (300.0 * yj_sin2(0.10471975511965979 * x))) * 0.6667));

138    }

139

140    private double Transform_yjy5(double x , double y)

141    {

142        double num = ((((-100.0 + (2.0 * x)) + (3.0 * y)) + ((0.2 * y) * y)) + ((0.1 * x) * y))

143                + (0.2 * Math.sqrt(Math.sqrt(x * x)));

144        num += ((20.0 * yj_sin2(18.849555921538762 * x)) + (20.0 * yj_sin2(6.283185307179588* x))) * 0.6667;

145        num += ((20.0 * yj_sin2(3.141592653589794 * y)) + (40.0 * yj_sin2(1.0471975511965981* y))) * 0.6667;

146        return (num + (((160.0 * yj_sin2(0.26179938779914952 * y)) + (320.0 * yj_sin2(0.10471975511965979 * y))) * 0.6667));

147    }

148

149    private MapPoint wgtochina_lb(int wg_flag , int wg_lng , int wg_lat , int wg_heit , int wg_week , int wg_time)

150    {

151        MapPoint point = null;

152        if (wg_heit <= 0x1388)

153        {

154            double num = wg_lng;

155            num /= 3686400.0;

156            double x = wg_lat;

157            x /= 3686400.0;

158            if (num < 72.004)

159            {

160                return point;

161            }

162            if (num > 137.8347)

163            {

164                return point;

165            }

166            if (x < 0.8293)

167            {

168                return point;

169            }

170            if (x > 55.8271)

171            {

172                return point;

173            }

174            if (wg_flag == 0)

175            {

176                IniCasm((double) wg_time, (double) wg_lng, (double) wg_lat);

177                point = new MapPoint();

178                point.setLatitude((double) wg_lng);

179                point.setLongitude((double) wg_lat);

180                return point;

181            }

182            casm_t2 = wg_time;

183            double num3 = (casm_t2 - casm_t1) / 1000.0;

184            if (num3 <= 0.0)

185            {

186                casm_t1 = casm_t2;

187                casm_f++;

188                casm_x1 = casm_x2;

189                casm_f++;

190                casm_y1 = casm_y2;

191                casm_f++;

192            }

193            else if (num3 > 120.0)

194            {

195                if (casm_f == 3.0)

196                {

197                    casm_f = 0.0;

198                    casm_x2 = wg_lng;

199                    casm_y2 = wg_lat;

200                    double num4 = casm_x2 - casm_x1;

201                    double num5 = casm_y2 - casm_y1;

202                    double num6 = Math.sqrt((num4 * num4) + (num5 * num5)) / num3;

203                    if (num6 > 3185.0)

204                    {

205                        return point;

206                    }

207                }

208                casm_t1 = casm_t2;

209                casm_f++;

210                casm_x1 = casm_x2;

211                casm_f++;

212                casm_y1 = casm_y2;

213                casm_f++;

214            }

215            double xx = Transform_yj5(num - 105.0, x - 35.0);

216            double yy = Transform_yjy5(num - 105.0, x - 35.0);

217            double num9 = wg_heit;

218            xx = ((xx + (num9 * 0.001)) + yj_sin2(wg_time * 0.0174532925199433)) + random_yj();

219            yy = ((yy + (num9 * 0.001)) + yj_sin2(wg_time * 0.0174532925199433)) + random_yj();

220            point = new MapPoint();

221            point.setX((num + Transform_jy5(x, xx)) * 3686400.0);

222            point.setY((x + Transform_jyj5(x, yy)) * 3686400.0);

223        }

224        return point;

225    }

226

227    private double yj_sin2(double x)

228    {

229        double num = 0.0;

230        if (x < 0.0)

231        {

232            x = -x;

233            num = 1.0;

234        }

235        int num2 = (int) (x / 6.28318530717959);

236        double num3 = x - (num2 * 6.28318530717959);

237        if (num3 > 3.1415926535897931)

238        {

239            num3 -= 3.1415926535897931;

240            if (num == 1.0)

241            {

242                num = 0.0;

243            }

244            else if (num == 0.0)

245            {

246                num = 1.0;

247            }

248        }

249        x = num3;

250        double num4 = x;

251        double num5 = x;

252        num3 *= num3;

253        num5 *= num3;

254        num4 -= num5 * 0.166666666666667;

255        num5 *= num3;

256        num4 += num5 * 0.00833333333333333;

257        num5 *= num3;

258        num4 -= num5 * 0.000198412698412698;

259        num5 *= num3;

260        num4 += num5 * 2.75573192239859E-06;

261        num5 *= num3;

262        num4 -= num5 * 2.50521083854417E-08;

263        if (num == 1.0)

264        {

265            num4 = -num4;

266        }

267        return num4;

268    }

269}

270

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