高德地图定位api以及导航和定位 位置的偏差

 <script type="text/javascript" src="http://webapi.amap.com/maps?v=1.4.2&key=37d9a4da394e46e29***d0521eb7"></script>

map = new AMap.Map('container', {
        resizeEnable: true
    });
    map.plugin('AMap.Geolocation', function() {
        geolocation = new AMap.Geolocation({
             enableHighAccuracy: true,//是否使用高精度定位，默认:true
             timeout: 10000,          //超过10秒后停止定位，默认：无穷大
             buttonOffset: new AMap.Pixel(10, 20),//定位按钮与设置的停靠位置的偏移量，默认：Pixel(10, 20)
             zoomToAccuracy: true,      //定位成功后调整地图视野范围使定位位置及精度范围视野内可见，默认：false
             buttonPosition:'RB'
        });
        map.addControl(geolocation);
        geolocation.getCurrentPosition();
        AMap.event.addListener(geolocation, 'complete', onComplete);//返回定位信息
        AMap.event.addListener(geolocation, 'error', onError);      //返回定位出错信息
    });
    //解析定位结果
    function onComplete(data) {
          var EndLatitude = document.getElementById("EndLatitude").value;
          var EndLongitude = document.getElementById("EndLongitude").value;
        var str=['定位成功'];
        str.push('经度：' + data.position.getLng());
        str.push('纬度：' + data.position.getLat());
      
        var gpsPoint = GPS.gcj_encrypt(data.position.getLat(), data.position.getLng());
       
       lng= gpsPoint.lon;
        lat= gpsPoint.lat;
     
        if(data.accuracy){
             str.push('精度：' + data.accuracy + ' 米');
        }//如为IP精确定位结果则没有精度信息
        str.push('是否经过偏移：' + (data.isConverted ? '是' : '否'));
      
      
        //var a = "http://api.map.baidu.com/direction?origin=latlng:" + position.coords.latitude + "," + position.coords.longitude + "|name:我的位置&destination=latlng:" + EndLatitude + "," + EndLongitude + "|name:目的地&mode=driving&region=成都&output=html&src=scnjw";
        //var a = "http://api.map.baidu.com/direction?origin=latlng:31.64380,105.00065|name:去嘛&destination=latlng:30.64380,104.00065|name:来嘛&mode=driving&region=成都&output=html&src=scnjw";
     //   var a = "http://uri.amap.com/navigation?from=" + position.coords.longitude + "," + position.coords.latitude + ",我的位置&to=" + EndLongitude + "," + EndLatitude + ",目的地&mode=car&policy=1&src=mypage&coordinate=gaode&callnative=0";
        
     var a = "http://uri.amap.com/navigation?from=" +lng+","+lat + ",我的位置&to=" + EndLongitude + "," + EndLatitude + ",目的地&mode=car&policy=1&src=mypage&coordinate=gaode&callnative=0";

        top.location = a;
        
        
    }
    //解析定位错误信息
    function onError(data) {
        document.getElementById('tip').innerHTML = '定位失败';
    }

                
    var GPS = {
            PI: 3.14159265358979324,
            x_pi: 3.14159265358979324 * 3000.0 / 180.0,
            delta: function (lat, lon) {
                var a = 6378245.0; //  a: 卫星椭球坐标投影到平面地图坐标系的投影因子。
                var ee = 0.00669342162296594323; //  ee: 椭球的偏心率。
                var dLat = this.transformLat(lon - 105.0, lat - 35.0);
                var dLon = this.transformLon(lon - 105.0, lat - 35.0);
                var radLat = lat / 180.0 * this.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) * this.PI);
                dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * this.PI);
                return {
                    'lat': dLat,
                    'lon': dLon
                };
            },
            //WGS-84 to GCJ-02
            gcj_encrypt: function (wgsLat, wgsLon) {
                if (this.outOfChina(wgsLat, wgsLon))
                    return {
                        'lat': wgsLat,
                        'lon': wgsLon
                    };

                var d = this.delta(wgsLat, wgsLon);
                return {
                    'lat': wgsLat + d.lat,
                    'lon': wgsLon + d.lon
                };
            },
            outOfChina: function (lat, lon) {
                if (lon < 72.004 || lon > 137.8347)
                    return true;
                if (lat < 0.8293 || lat > 55.8271)
                    return true;
                return false;
            },
            transformLat: function (x, y) {
                var ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
                ret += (20.0 * Math.sin(6.0 * x * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0;
                ret += (20.0 * Math.sin(y * this.PI) + 40.0 * Math.sin(y / 3.0 * this.PI)) * 2.0 / 3.0;
                ret += (160.0 * Math.sin(y / 12.0 * this.PI) + 320 * Math.sin(y * this.PI / 30.0)) * 2.0 / 3.0;
                return ret;
            },
            transformLon: function (x, y) {
                var ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
                ret += (20.0 * Math.sin(6.0 * x * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0;
                ret += (20.0 * Math.sin(x * this.PI) + 40.0 * Math.sin(x / 3.0 * this.PI)) * 2.0 / 3.0;
                ret += (150.0 * Math.sin(x / 12.0 * this.PI) + 300.0 * Math.sin(x / 30.0 * this.PI)) * 2.0 / 3.0;
                return ret;
            }
        };