//坐标正算lbxy(double l, double b, double *x, double *y, int l0){double sa,sb,sep,sn,sy2,st,sm,sx,hb;double xx,yy,hd,sd;，下面我们就来说一说关于北京54坐标系怎样转换经纬度?我们一起去了解并探讨一下这个问题吧!
北京54坐标系怎样转换经纬度
//坐标正算lbxy(double l, double b, double *x, double *y, int l0){double sa,sb,sep,sn,sy2,st,sm,sx,hb;double xx,yy,hd,sd;
//判断值的范围if (l > 360 || l < 0 || b > 360 || b < 0){*x = l;*y = b;return;}
l = l-l0;sa = 6378245; sb = 6356863.019;sep= 0.006738525415;hd = b*PI;hb = hd/180.0;st = tan(hb);sn=pow(sa,(double)2)/sqrt(pow(sa,(double)2)*pow(cos(hb),(double)2) pow(sb,(double)2)*pow(sin(hb),(double)2));
sy2=sep*pow(cos(hb),(double)2);sd = cos(hb)*l*PI;sm = sd/180.0;sx = 111134.861*b-(32005.78*sin(hb) 133.924*pow(sin(hb),(double)3) 0.697*pow(sin(hb),(double)5))*cos(hb);xx = sx sn*st*(0.5*pow(sm,(double)2) 1.0/24.0*(5.0-pow(st,(double)2) 9.0*sy2)*pow(sm,(double)4));yy = sn*(sm 1.0/6.0*(1.0-pow(st,(double)2) sy2)*pow(sm,(double)3) 1.0/120.0*(5.0-18.0*pow(st,(double)2) pow(st,(double)4))*pow(sm,(double)5));*x = xx;*y = yy 500000;}
//坐标反算xylb(double l0, double x, double y, double *l, double *b){double bf,vf,nf,ynf,tf,yf2,hbf;double sa,sb,se2,sep2,mf;double w1,w2,w,w3,w4;double pi = 3.1415926;
x = x/1000000.0;y = y - 500000.0;bf = 9.04353692458*x-0.00001007623*pow(x,2.0)-0.00074438304*pow(x,3.0)-0.00000463064*pow(x,4.0) 0.00000505846*pow(x,5.0)-0.00000016754*pow(x,6.0);hbf = bf * pi/ 180.0;sa = 6378245.0;sb = 6356863.019;se2 = 0.006693421623;sep2 = 0.006738525415;
w1 = sin(hbf);w2 = 1.0 - se2 * pow(w1,(double)2);w = sqrt(w2);mf = sa*(1.0-se2)/pow(w,(double)3);w3 = cos(hbf);
w4 = pow(sa,(double)2)*pow(w3,(double)2) pow(sb,(double)2)*pow(w1,(double)2);nf = pow(sa,(double)2) / sqrt(w4);
ynf = y/nf;vf = nf/mf;tf = tan(hbf);yf2 = sep2 * pow(w3, (double)2);
*b = bf - 1.0/2.0 * vf * tf * (pow(ynf,(double)2)-1.0/12.0*(5.0 3.0*pow(tf,(double)2) yf2-9.0*yf2*pow(tf,(double)2))*pow(ynf,(double)4))*180.0/pi;*l = 1.0/w3*ynf*(1.0-1.0/6.0*(1.0 2.0*pow(tf,(double)2) yf2)*pow(ynf,(double)2) 1.0/120.0*(5.0 28.0*pow(tf,(double)2) 24.0*pow(tf,(double)2) 6.0*yf2 8.0*yf2*pow(tf,(double)2))*pow(ynf,(double)4))*180.0/pi;*l = l0 *l;}
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