public static void enu2ecefCov(GMatrix ecefCov, GMatrix enuCov, LLA refLLA) {
double lambda = refLLA.longitude;
double phi = refLLA.latitude;
GMatrix R = new GMatrix(6, 6);
GMatrix Rt = new GMatrix(6, 6);
GMatrix tmp1 = new GMatrix(6, 6);
GMatrix tmp2 = new GMatrix(6, 6);
R.setElement(0, 0, -Math.sin(lambda));
R.setElement(0, 1, -Math.sin(phi)*Math.cos(lambda));
R.setElement(0, 2, Math.cos(phi)*Math.cos(lambda));
R.setElement(1, 0, Math.cos(lambda));
R.setElement(1, 1, -Math.sin(phi)*Math.sin(lambda));
R.setElement(1, 2, Math.cos(phi)*Math.sin(lambda));
R.setElement(2, 0, 0);
R.setElement(2, 1, Math.cos(phi));
R.setElement(2, 2, Math.sin(phi));
R.setElement(3, 3, -Math.sin(lambda));
R.setElement(3, 4, -Math.sin(phi)*Math.cos(lambda));
R.setElement(3, 5, Math.cos(phi)*Math.cos(lambda));
R.setElement(4, 3, Math.cos(lambda));
R.setElement(4, 4, -Math.sin(phi)*Math.sin(lambda));
R.setElement(4, 5, Math.cos(phi)*Math.sin(lambda));
R.setElement(5, 3, 0);
R.setElement(5, 4, Math.cos(phi));
R.setElement(5, 5, Math.sin(phi));
Rt.transpose(R);
tmp1.mul(enuCov, R);
ecefCov.mul(Rt, tmp1);
}