Example

Determine the look angles and the range for the situation given below.

 latitude of the earth station (l_E)=-20 deg Longitude of earth station (f_E)=-30 deg, Longitude of sub satellite point f_s=+30 deg; height = 35,786 km radiuses of earth = 6378.14 km. 

Solution:
f_E=-20 deg
l_E=-30 deg
f_s=+30 deg
Height = 35,786 km
Radius of earth = 6378.14 km.

From the equation        
                                   B = - 30 – (+30) =-60^o

From the equation;
                                            = -tan |-60|/sin(-20)
                                            = tan 60/sin20
                                            = 5.064
                                           A = tan^-15.064
                 Azimuth angle AZ=78.83 deg.

From the equation            
                                     Cos c = cos(-60) cos (-20)
                                              =o.4698
and therefore sin c =0.8827
                   R_E + h =42164.14 km
       d = squrt(6375.64²+42,164.14²–2*6375.64 *42,164.14*0.4698)
           = 39,571 km
From the equation
                                    = 42.164.14 * 0.8827 / 39,571
                                    = 0.9405 and therefore 

                 Elevation angle EI =18.86 deg.