欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

地图经纬度坐标系

程序员文章站 2022-07-02 08:45:19
...

在开发过程中用到地图服务,一般集成百度、高德、腾讯等,若仅仅是显示功能,使用ios自带MKMapView为首选(中国区为高德数据),但往往出现经纬度偏移等问题,原因莫过于各地图间使用的坐标系不同。

• WGS-84:是国际标准,GPS坐标(Google Earth使用、或者GPS模块)
• GCJ-02:中国坐标偏移标准,Google地图、高德、腾讯使用
• BD-09 :百度坐标偏移标准,Baidu地图使用

转换工具类:

WJLocationTransform.h
#import <Foundation/Foundation.h>
#import <CoreLocation/CLLocation.h>

@interface WJLocationTransform : NSObject

/*
 坐标系:
 WGS-84:是国际标准,GPS坐标(Google Earth使用、或者GPS模块)
 GCJ-02:中国坐标偏移标准,Google Map、高德、腾讯使用
 BD-09 :百度坐标偏移标准,Baidu Map使用
 */

#pragma mark - 中国坐标 转到 百度坐标
+ (CLLocationCoordinate2D)transformFromGCJToBaidu:(CLLocationCoordinate2D)p;

#pragma mark - 百度坐标 转到 中国坐标
+ (CLLocationCoordinate2D)transformFromBaiduToGCJ:(CLLocationCoordinate2D)p;

#pragma mark - GPS坐标 转到 中国坐标
+ (CLLocationCoordinate2D)transformFromWGSToGCJ:(CLLocationCoordinate2D)wgsLoc;

#pragma mark - 中国坐标 转到 GPS坐标
+ (CLLocationCoordinate2D)transformFromGCJToWGS:(CLLocationCoordinate2D)p;

@end
WJLocationTransform.m
#import "WJLocationTransform.h"

static const double a = 6378245.0;
static const double ee = 0.00669342162296594323;
static const double pi = M_PI;
static const double xPi = M_PI  * 3000.0 / 180.0;

@implementation WJLocationTransform

#pragma mark - 中国坐标 转到 百度坐标
+ (CLLocationCoordinate2D)transformFromGCJToBaidu:(CLLocationCoordinate2D)p {
    long double z = sqrt(p.longitude * p.longitude + p.latitude * p.latitude) + 0.00002 * sqrt(p.latitude * pi);
    long double theta = atan2(p.latitude, p.longitude) + 0.000003 * cos(p.longitude * pi);
    CLLocationCoordinate2D geoPoint;
    geoPoint.latitude  = (z * sin(theta) + 0.006);
    geoPoint.longitude = (z * cos(theta) + 0.0065);
    return geoPoint;
}

#pragma mark - 百度坐标 转到 中国坐标
+ (CLLocationCoordinate2D)transformFromBaiduToGCJ:(CLLocationCoordinate2D)p {
    double x = p.longitude - 0.0065, y = p.latitude - 0.006;
    double z = sqrt(x * x + y * y) - 0.00002 * sin(y * xPi);
    double theta = atan2(y, x) - 0.000003 * cos(x * xPi);
    CLLocationCoordinate2D geoPoint;
    geoPoint.latitude  = z * sin(theta);
    geoPoint.longitude = z * cos(theta);
    return geoPoint;
}

#pragma mark - GPS坐标 转到 中国坐标
+ (CLLocationCoordinate2D)transformFromWGSToGCJ:(CLLocationCoordinate2D)wgsLoc {
    CLLocationCoordinate2D adjustLoc;
    if([self isLocationOutOfChina:wgsLoc]) {
        adjustLoc = wgsLoc;
    }
    else {
        double adjustLat = [self transformLatWithX:wgsLoc.longitude - 105.0 withY:wgsLoc.latitude - 35.0];
        double adjustLon = [self transformLonWithX:wgsLoc.longitude - 105.0 withY:wgsLoc.latitude - 35.0];
        long double radLat = wgsLoc.latitude / 180.0 * pi;
        long double magic = sin(radLat);
        magic = 1 - ee * magic * magic;
        long double sqrtMagic = sqrt(magic);
        adjustLat = (adjustLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
        adjustLon = (adjustLon * 180.0) / (a / sqrtMagic * cos(radLat) * pi);
        adjustLoc.latitude = wgsLoc.latitude + adjustLat;
        adjustLoc.longitude = wgsLoc.longitude + adjustLon;
    }
    return adjustLoc;
}

#pragma mark - 中国坐标 转到 GPS坐标
+ (CLLocationCoordinate2D)transformFromGCJToWGS:(CLLocationCoordinate2D)p {
    double threshold = 0.00001;
    
    // The boundary
    double minLat = p.latitude - 0.5;
    double maxLat = p.latitude + 0.5;
    double minLng = p.longitude - 0.5;
    double maxLng = p.longitude + 0.5;
    
    double delta = 1;
    int maxIteration = 30;
    // Binary search
    while(true) {
        CLLocationCoordinate2D leftBottom  = [[self class] transformFromWGSToGCJ:(CLLocationCoordinate2D){.latitude = minLat,.longitude = minLng}];
        CLLocationCoordinate2D rightBottom = [[self class] transformFromWGSToGCJ:(CLLocationCoordinate2D){.latitude = minLat,.longitude = maxLng}];
        CLLocationCoordinate2D leftUp      = [[self class] transformFromWGSToGCJ:(CLLocationCoordinate2D){.latitude = maxLat,.longitude = minLng}];
        CLLocationCoordinate2D midPoint    = [[self class] transformFromWGSToGCJ:(CLLocationCoordinate2D){.latitude = ((minLat + maxLat) / 2),.longitude = ((minLng + maxLng) / 2)}];
        delta = fabs(midPoint.latitude - p.latitude) + fabs(midPoint.longitude - p.longitude);
        
        if(maxIteration-- <= 0 || delta <= threshold) {
            return (CLLocationCoordinate2D){.latitude = ((minLat + maxLat) / 2),.longitude = ((minLng + maxLng) / 2)};
        }
        
        if(isContains(p, leftBottom, midPoint)) {
            maxLat = (minLat + maxLat) / 2;
            maxLng = (minLng + maxLng) / 2;
        } else if(isContains(p, rightBottom, midPoint)) {
            maxLat = (minLat + maxLat) / 2;
            minLng = (minLng + maxLng) / 2;
        } else if(isContains(p, leftUp, midPoint)) {
            minLat = (minLat + maxLat) / 2;
            maxLng = (minLng + maxLng) / 2;
        } else {
            minLat = (minLat + maxLat) / 2;
            minLng = (minLng + maxLng) / 2;
        }
    }
    
}

+ (double)transformLatWithX:(double)x withY:(double)y {
    double lat = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * sqrt(fabs(x));
    
    lat += (20.0 * sin(6.0 * x * pi) + 20.0 *sin(2.0 * x * pi)) * 2.0 / 3.0;
    lat += (20.0 * sin(y * pi) + 40.0 * sin(y / 3.0 * pi)) * 2.0 / 3.0;
    lat += (160.0 * sin(y / 12.0 * pi) + 320 * sin(y * pi / 30.0)) * 2.0 / 3.0;
    return lat;
}

+ (double)transformLonWithX:(double)x withY:(double)y {
    double lon = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * sqrt(fabs(x));
    lon += (20.0 * sin(6.0 * x * pi) + 20.0 * sin(2.0 * x * pi)) * 2.0 / 3.0;
    lon += (20.0 * sin(x * pi) + 40.0 * sin(x / 3.0 * pi)) * 2.0 / 3.0;
    lon += (150.0 * sin(x / 12.0 * pi) + 300.0 * sin(x / 30.0 * pi)) * 2.0 / 3.0;
    return lon;
}

#pragma mark - 判断某个点point是否在p1和p2之间
static bool isContains(CLLocationCoordinate2D point, CLLocationCoordinate2D p1, CLLocationCoordinate2D p2) {
    return (point.latitude >= MIN(p1.latitude, p2.latitude) && point.latitude <= MAX(p1.latitude, p2.latitude)) && (point.longitude >= MIN(p1.longitude,p2.longitude) && point.longitude <= MAX(p1.longitude, p2.longitude));
}

#pragma mark - 判断是不是在中国
+ (BOOL)isLocationOutOfChina:(CLLocationCoordinate2D)location {
    if (location.longitude < 72.004 || location.longitude > 137.8347 || location.latitude < 0.8293 || location.latitude > 55.8271)
        return YES;
    return NO;
}

@end

附:

百度地图转换为自家经纬度坐标:
http://lbsyun.baidu.com/index.php?title=webapi/guide/changeposition

高德地图转换为自家经纬度坐标:
http://lbs.amap.com/api/webservice/guide/api/convert

转载于:https://www.jianshu.com/p/04a646baeb8f