java计算两个经纬度相对的方向角

package ejbModule.Map.mgr;

public class JWD {

static double Rc = 6378137; // 赤道半径

static double Rj = 6356725; // 极半径

double m_LoDeg, m_LoMin, m_LoSec; // longtitude 经度

double m_LaDeg, m_LaMin, m_LaSec;

double m_Longitude, m_Latitude;

double m_RadLo, m_RadLa;

double Ec;

double Ed;

public static void main(String[] args) {

// TODO Auto-generated method stub

// JWD B = JWD.GetJWDB(113.344,23.1346, 0.112, 130);

// System.out.println(B.m_Longitude);

// System.out.println(B.m_Latitude);

JWD A = new JWD(113.344,23.1346);

JWD B = new JWD(113.33986835073915,23.136261252139477);

System.out.println(JWD.angle(A, B));

}

public JWD(double longitude, double latitude)

{

m_LoDeg = (int)longitude;

m_LoMin = (int)((longitude - m_LoDeg)*60);

m_LoSec = (longitude - m_LoDeg - m_LoMin/60.)*3600;

m_LaDeg = (int)latitude;

m_LaMin = (int)((latitude - m_LaDeg)*60);

m_LaSec = (latitude - m_LaDeg - m_LaMin/60.)*3600;

m_Longitude = longitude;

m_Latitude = latitude;

m_RadLo = longitude * Math.PI/180.;

m_RadLa = latitude * Math.PI/180.;

Ec = Rj + (Rc - Rj) * (90.-m_Latitude) / 90.;

Ed = Ec * Math.cos(m_RadLa);

}

public static JWD GetJWDB(JWD A, double distance, double angle)

{

double dx = distance*1000 * Math.sin(angle * Math.PI /180.);

double dy = distance*1000 * Math.cos(angle * Math.PI /180.);

//double dx = (B.m_RadLo - A.m_RadLo) * A.Ed;

//double dy = (B.m_RadLa - A.m_RadLa) * A.Ec;

double BJD = (dx/A.Ed + A.m_RadLo) * 180./Math.PI;

double BWD = (dy/A.Ec + A.m_RadLa) * 180./Math.PI;

JWD B = new JWD(BJD, BWD);

return B;

}

//! 已知点A经纬度，根据B点据A点的距离，和方位，求B点的经纬度

/*!

* /param longitude 已知点A经度

* /param latitude 已知点A纬度

* /param distance B点到A点的距离

* /param angle B点相对于A点的方位

* /return B点的经纬度坐标

*/

public static JWD GetJWDB(double longitude, double latitude, double distance, double angle)

{

JWD A = new JWD(longitude,latitude);

return GetJWDB(A, distance, angle);

}

//! 计算点A 和 点B的经纬度，求他们的距离和点B相对于点A的方位

/*!

* \param A A点经纬度

* \param B B点经纬度

* \param angle B相对于A的方位, 不需要返回该值，则将其设为空

* \return A点B点的角度

*/

public static double angle(JWD A, JWD B)

{

double dx = (B.m_RadLo - A.m_RadLo) * A.Ed;

double dy = (B.m_RadLa - A.m_RadLa) * A.Ec;

// double out = Math.sqrt(dx * dx + dy * dy);

double angle = 0.0;

angle = Math.atan(Math.abs(dx

))*180./Math.PI;

// 判断象限

double dLo = B.m_Longitude - A.m_Longitude;

double dLa = B.m_Latitude - A.m_Latitude;

if(dLo > 0 && dLa <= 0) {

angle = (90. - angle) + 90.;

}

else if(dLo <= 0 && dLa < 0) {

angle = angle + 180.;

}

else if(dLo < 0 && dLa >= 0) {

angle = (90. - angle) + 270;

}

return angle;

}

}