[Erledigt] Hilfe für Winkelberechnungen erbeten

#include <math.h>
#include <stdio.h>
#include <stdlib.h>


#define SAT_EARTH_RATIO    0.1513 // the Earth's radius, divided by the distance from the Earth's center to the satellite
#define SAT_VISIBILITY_LAT 810    // the absolute latitude beyond which no satellite can be seen


#define RAD(x) ((x) * M_PI / 1800)
#define DEG(x) ((x) * 1800 / M_PI)


template<class T> inline T sqr(T a) { return a * a; }


struct tSetup {
  int SiteLat;
  int SiteLon;
  } Setup;


int NormalizeAngle(int Angle)
{
  while (Angle < -1800)
        Angle += 3600;
  while (Angle > 1800)
        Angle -= 3600;
  return Angle;
}


int CalcHourAngle(int Longitude)
{
  double Delta = RAD(Longitude - Setup.SiteLon);
  double Lat = RAD(Setup.SiteLat);
  int Sign = Setup.SiteLat >= 0 ? -1 : 1; // angles to the right are positive, angles to the left are negative
  return Sign * round(DEG(atan2(sin(Delta), cos(Delta) - cos(Lat) * SAT_EARTH_RATIO)));
}


int CalcLongitude(int HourAngle)
{
  double Lat = RAD(Setup.SiteLat);
  double Lon = RAD(Setup.SiteLon);
  double Alpha = RAD(HourAngle);
  int Sign = HourAngle >= 0 ? -1 : 1;
  double Delta = Alpha - asin(sin(M_PI - Alpha) * SAT_EARTH_RATIO * cos(Lat));
  Sign = Setup.SiteLat >= 0 ? 1 : -1;
  return NormalizeAngle(round(DEG(Lon - Sign * Delta)));
}


int main(void)
{
  Setup.SiteLat = 0;
  Setup.SiteLon = 0;
  for (int i = -650; i <= 650; i += 50)
      fprintf(stderr, "%5d %5d %5d -> %5d %5d\n", Setup.SiteLat, Setup.SiteLon, i, CalcLongitude(i), CalcHourAngle(CalcLongitude(i)));
  return 0;
}

0     0  -650 ->   571  -650
    0     0  -600 ->   525  -600
    0     0  -550 ->   479  -550
    0     0  -500 ->   433  -500
    0     0  -450 ->   389  -450
    0     0  -400 ->   344  -400
    0     0  -350 ->   300  -350
    0     0  -300 ->   257  -300
    0     0  -250 ->   213  -250
    0     0  -200 ->   170  -200
    0     0  -150 ->   128  -151
    0     0  -100 ->    85  -100
    0     0   -50 ->    42   -49
    0     0     0 ->     0     0
    0     0    50 ->   -42    49
    0     0   100 ->   -85   100
    0     0   150 ->  -128   151
    0     0   200 ->  -170   200
    0     0   250 ->  -213   250
    0     0   300 ->  -257   300
    0     0   350 ->  -300   350
    0     0   400 ->  -344   400
    0     0   450 ->  -389   450
    0     0   500 ->  -433   500
    0     0   550 ->  -479   550
    0     0   600 ->  -525   600
    0     0   650 ->  -571   650