nutation static method

Nutation nutation(
  1. double t
)

计算黄经章动及交角章动

@param t t @return 计算黄经章动及交角章动

Implementation

static Nutation nutation(double t) {
  Nutation d = new Nutation();
  d.Lon = 0;
  d.Obl = 0;
  t /= 36525;
  double c, t1 = t, t2 = t1 * t1, t3 = t2 * t1, t4 = t3 * t1; // t5=t4*t1;
  for (int i = 0; i < nutB.length; i += 9) {
    c = nutB[i] +
        nutB[i + 1] * t1 +
        nutB[i + 2] * t2 +
        nutB[i + 3] * t3 +
        nutB[i + 4] * t4;
    d.Lon += (nutB[i + 5] + nutB[i + 6] * t / 10) * sin(c); // 黄经章动
    d.Obl += (nutB[i + 7] + nutB[i + 8] * t / 10) * cos(c); // 交角章动
  }
  d.Lon /= SECOND_PER_RAD * 10000; // 黄经章动
  d.Obl /= SECOND_PER_RAD * 10000; // 交角章动
  return d;
}