ECEF到lla(lat,lon,alt)在java中
作者:互联网
我查看了网站上的帖子,但没有发现我的问题……
正如头条说我试图从ecef转换为lla.
我正在使用这个文件:Conversion article
在直接公式中,而不是迭代公式
和本网站的结果比较:ECEF2LLA
我在java中开发,所以我的代码如下:
public static final double a = 6378137;
public static final double f = 1/298.257223563;
public static final double b = a*(1-f);
public static final double e = Math.sqrt((Math.pow(a, 2)-Math.pow(b, 2))/Math.pow(a, 2));
public static final double e2 = Math.sqrt((Math.pow(a, 2)-Math.pow(b, 2))/Math.pow(b, 2));
public static double[] ecef2lla(double x , double y , double z){
double[] lla = {0,0,0};
double lon,lat,height,N;
double p = Math.sqrt(Math.pow(x, 2)+Math.pow(y, 2));
double theta = Math.atan((z*a)/(p*b));
lon = Math.atan(y/x);
lon = lon*180/Math.PI;
lat = Math.atan(((z+Math.pow(e2, 2)*b*Math.pow(Math.sin(theta), 3))/((p-Math.pow(e,2)*a*Math.pow(Math.cos(theta), 3)))));
lat = (lat*180)/Math.PI;
N= a/(Math.sqrt(1-Math.pow(e*Math.sin(lat), 2)));
height = (p/Math.cos(theta)) - N;
lla[0] = lon;
lla[1] = lat;
lla[2] = height;
return lla;
}
我的身高数据错了.
我试图移动到弧度和度数,什么不是.
先感谢您 !
解决方法:
我发现这篇文章并准备在我的应用程序的一部分中使用“接受的答案”但我决定先运行几个测试来验证算法.我使用了在线转换计算器(http://www.sysense.com/products/ecef_lla_converter/index.html)生成的样本数据.如下面的输出所示,我得到的结果不是很好.
-----Test 1---------
Inputs: -576793.17, -5376363.47, 3372298.51
Expected: 32.12345, -96.12345, 500.0
Actuals: 32.12306332822881, 83.87654999786477, 486.5472474489361
-----Test 2---------
Inputs: 2297292.91, 1016894.94, -5843939.62
Expected: -66.87654, 23.87654, 1000.0
Actuals: -66.876230479461, 23.87653991401422, 959.6879360172898
然后我使用以下帖子(https://gist.github.com/klucar/1536194)中的代码重新进行相同的测试,得到了更好的结果,如下面的输出所示.
-----Test 1---------
Inputs: -576793.17, -5376363.47, 3372298.51
Expected: 32.12345, -96.12345, 500.0
Actuals: 32.12345004807767, -96.12345000213524, 499.997958839871
-----Test 2---------
Inputs: 2297292.91, 1016894.94, -5843939.62
Expected: -66.87654, 23.87654, 1000.0
Actuals: -66.87654001741278, 23.87653991401422, 999.9983866894618
我没有花时间在“接受的答案”中提供的解决方案中找到错误,但我建议的答案是:使用此代码…
/*
*
* ECEF - Earth Centered Earth Fixed
*
* LLA - Lat Lon Alt
*
* ported from matlab code at
* https://gist.github.com/1536054
* and
* https://gist.github.com/1536056
*/
// WGS84 ellipsoid constants
private final double a = 6378137; // radius
private final double e = 8.1819190842622e-2; // eccentricity
private final double asq = Math.pow(a,2);
private final double esq = Math.pow(e,2);
private double[] ecef2lla(double[] ecef){
double x = ecef[0];
double y = ecef[1];
double z = ecef[2];
double b = Math.sqrt( asq * (1-esq) );
double bsq = Math.pow(b,2);
double ep = Math.sqrt( (asq - bsq)/bsq);
double p = Math.sqrt( Math.pow(x,2) + Math.pow(y,2) );
double th = Math.atan2(a*z, b*p);
double lon = Math.atan2(y,x);
double lat = Math.atan2( (z + Math.pow(ep,2)*b*Math.pow(Math.sin(th),3) ), (p - esq*a*Math.pow(Math.cos(th),3)) );
double N = a/( Math.sqrt(1-esq*Math.pow(Math.sin(lat),2)) );
double alt = p / Math.cos(lat) - N;
// mod lat to 0-2pi
lon = lon % (2*Math.PI);
// correction for altitude near poles left out.
double[] ret = {lat, lon, alt};
return ret;
}
标签:java,math,gps,coordinate-systems,latitude-longitude 来源: https://codeday.me/bug/20190728/1566212.html