Azimuth

using MathNet.Spatial.Euclidean;
using System;

namespace ConsoleApp1 {
    class Program {
        static double DegreeToRadian(double angle) {
            return Math.PI * angle / 180.0;
        }

        static double RadianToDegree(double angle) {
            return angle * (180.0 / Math.PI);
        }

        static void Main(string[] args) {
            double[,] data = {
                {
                    -18.9689, // earthLat
                     -49.465, // earthLon
                        6378, // earthHei

                      -27.14, // satLat
                      105.39, // satLon
                     6801.91, // satHei

                    // Az: ~ 151.45
                    // Elev: ~ -62.8
                },
            };

            for(int i = 0; i < data.GetLength(0); i++) {
                CalcAz.CalcAzEl(
                    DegreeToRadian(data[i, 0]),
                    DegreeToRadian(data[i, 1]),
                    DegreeToRadian(data[i, 2]),
                    DegreeToRadian(data[i, 3]),
                    DegreeToRadian(data[i, 4]),
                    DegreeToRadian(data[i, 5]),
                    out double az, out double elev);

                Console.WriteLine("Modelo:");
                Console.WriteLine(" - earthLat: {0}", data[i, 0]);
                Console.WriteLine(" - earthLon: {0}", data[i, 1]);
                Console.WriteLine(" - earthHei: {0}", data[i, 2]);
                Console.WriteLine(" - satLat:   {0}", data[i, 3]);
                Console.WriteLine(" - satLon:   {0}", data[i, 4]);
                Console.WriteLine(" - satHei:   {0}", data[i, 5]);

                Console.WriteLine("Resultado:");
                Console.WriteLine(" - az:   {0}",
                    RadianToDegree(az));
                Console.WriteLine(" - elev: {0}",
                    RadianToDegree(elev));
            }

            Console.Read();
        }
    }

    public class CalcAz {
        // altAnt = raio da terra
        public static void CalcAzEl(double latAnt, double longAnt, double altAnt, double latSat, double longSat, double altSat, out double az, out double elev) {
            Vector3D vectO = BuildPolVector(latAnt, longAnt, altAnt);
            Vector3D vectS = BuildPolVector(latSat, longSat, altSat);

            Vector3D vectR = vectS - vectO;

            //Como encontrar o U, E, N?
            UnitVector3D vectE = (BuildPolVector(latAnt, longAnt + 1, altAnt) - vectO).Normalize();
            UnitVector3D vectN = (BuildPolVector(latAnt + 1, longAnt, altAnt) - vectO).Normalize();
            //E - Lest N - Norte
            //U = vectO.normalize
            UnitVector3D vectRNorm = vectR.Normalize();

            elev = Math.Asin(vectRNorm.DotProduct(vectO.Normalize()));

            az = Math.Atan((vectRNorm.DotProduct(vectE)) / (vectRNorm.DotProduct(vectN)));
        }

        private static Vector3D BuildPolVector(double longi, double lat, double alt) {

            return new Vector3D(alt * Math.Sin(lat) * Math.Cos(longi),
                alt * Math.Sin(lat) * Math.Sin(longi),
                alt * Math.Sin(lat));

        }
    }
}