这是我的代码:
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("Test ");
gaussPositiveFormula(36.082846593,119.5520122887);
}
/* gauss-kruger projection forward calculation
* params:B latitude,L longitude
*/
public static void gaussPositiveFormula (double B,double L){
double L0 = (L%15)>7.5?Math.floor(L/15+1)*15:Math.floor(L/15)*15; // longitude of central meridian
double l = L - L0;
int [] array_B = DmsRad.dec2Dms(B);
B = DmsRad.dms2rad(array_B[0], array_B[1], array_B[2]);
int [] array_L = DmsRad.dec2Dms(L);
L = DmsRad.dms2rad(array_L[0], array_L[1], array_L[2]);
int [] array_L0 = DmsRad.dec2Dms(L0);
L0 = DmsRad.dms2rad(array_L0[0], array_L0[1], array_L0[2]);
System.out.println("B = "+ B);
System.out.println("L = " + L);
//WGS-84 spheroid params
double a = 6378137.0; //major semi axis
double efang = 0.0066943799013; //square of e
double e2fang = 0.00673949674227; //suqre of e2
double c = 6399593.6258;
double sinB = Math.sin(B);
double cosB = Math.cos(B);
double t = Math.tan(B);
double p = 180*3600/Math.PI;
double nfang = e2fang*cosB*cosB;
double m = l*cosB;
double V = Math.pow((1+e2fang*cosB*cosB), 1/2.0);
double N = a*Math.pow((1-efang*sinB*sinB),-1/2);
N = c/V;
System.out.println("L0 = "+ L0);
System.out.println("sinB = "+ sinB);
System.out.println("cosB = "+ cosB);
System.out.println("t = "+ t);
System.out.println("p = "+ p);
System.out.println("nfang = "+ nfang);
System.out.println("l = "+ l);
System.out.println("N = "+ N);
//principal curvatures
double m0,m2,m4,m6,m8;
m0 = a*(1-efang);
m2 = 3.0/2.0*efang*m0;
m4 = efang*m2*5.0/4.0;
m6 = efang*m4*7.0/6.0;
m8 = efang*m6*9.0/8.0;
//meridional curvature
double a0,a2,a4,a6,a8;
a0 = m0 + m2/2.0 + m4*3.0/8.0 + m6*5.0/16.0 + m8*35.0/128.0;
a2 = m2/2.0 + m4/2.0 + m6*15.0/32.0 + m8*7.0/16.0;
a4 = m4/8.0 + m6*3.0/16.0 + m8*7.0/32.0;
a6 = m6/32.0 + m8/16.0;
a8 = m8/128.0;
//meridional arc length calculate
double X0 = a0*B -a2*Math.sin(2*B)/2.0 + a4*Math.sin(4*B)/4.0 - a6*Math.sin(6*B)/6.0 + a8*Math.sin(8*B)/8.0;
System.out.println("X0 = "+ X0);
double x = X0 + N*sinB*cosB*l*l/(p*p*2.0) + N*sinB*Math.pow(cosB, 3)*(5-t*t+9*nfang+4*nfang*nfang)*Math.pow(l, 4)/(24*Math.pow(p, 4)) + N*sinB*Math.pow(cosB, 5)*(61-58*t*t + Math.pow(t, 4))*Math.pow(l, 6)/(720*Math.pow(p, 6));
System.out.println("x = "+ x);
double y = N*cosB*l/p + N*Math.pow(cosB, 3)*(1-t*t + nfang)*Math.pow(l, 3)/(6*Math.pow(p, 3)) + N*Math.pow(cosB, 5)*(5-18*t*t +Math.pow(t, 4) + 14*nfang -58*nfang*t*t)*Math.pow(l, 5)/(120*Math.pow(p, 5));
System.out.println("y = "+ y);
System.out.println(N*cosB*l/p );
}
//transform coordinates to degrees
public static double formToDegress (double x){
double x1 = Math.abs(x);
double degree,min,sec;
degree = Math.floor(x1);
x1 = x1-degree;
min = Math.floor(x1*60);
x1 = (x1*60-min);
sec = x1*60;
double s = degree*3600+min*60+sec;
return s;
}
}
这是我的代码,计算结果相当正确。
我发现参数l
是主要因素。例如坐标是(36.0,119.0),L = 119.0
,我已经计算了L0 = 120.0
,对吗?并计算l = L -L0
,我应该转换l
度数吗?
m0~m8
是常数,是由WGS84参数计算出来的,我觉得是对的。a0~a8
使用方法相同。
我的问题是:如何使用高斯公式?公式的参数,需要我转换哪种格式?</p>