Azimuth calculator error

[george7378]

Hi all,

I am making a C++ azimuth calculator using the formula at the top of this page:

Launch Azimuth - OrbiterWiki

I am using the formula to calculate 'example 1' on the page, with the Cape Canaveral - ISS launch. Instead of the 45 degree answer, I get -144 degrees. Here is the code:

#include <iostream>
#include <math.h>
#include <process.h>
#include <conio.h>

using namespace std;

int main ()
{

  double lat;
  double az;
  double inc;
  char ch;

start:
  cout << "To calculate azimuth (degrees), enter target inclination and press enter: " << "\n";
  cin >> inc;
  cout << "To calculate azimuth (degrees), enter departure latitude and press enter: " << "\n";
  cin >> lat;
  if (lat > inc) goto error;
  az = asin(cos (inc)/cos (lat));
  cout << "\n" << "Azimuth is: " << az * 100 << " degrees";
  goto end;

end:
  cout << "\n" << "\n" << "Press enter to recalculate.";
  ch = _getch();
  if (ch == 13)
  system("cls");
  goto start;

error:
  cout << "\n" << "Can't calculate if inclination is lower than latitude.";
  goto end;

  return 0;
}

[george7378]

Not to worry - it's the degrees/radians problem. Solved.