Algorithm 1 Changing uniform satellite for HDOP improvement (nu = 5)

1: void function changing uniform satellite(azimuth_satellites, elevation_satellites)

2:  nu = 5;

3:  sat_me = find satellite of minimum elevation(elevation_satellites);

4:  vec_s = generate vector of satellites(azimuth_satellites, elevation_satellites);

5:  vec_rp = generate vector of regular polygon(nu, sat_me);

6:  sat_selec = select satellite of nearest regular polygon vector(vec_s, vec_rp);

7:  case_selec = check case of selected satellite(sat_selec);

8:  if case_selec == 3

9:   sat_case2 = change satellite from case 3 to case 2;

10:   [case_selec, sat_selec] = compare case(case_selec, sat_selec, sat_case2);

11:  end

12:  if case_selec == 2

13:   sat_case1 = change satellite from case 2 to case 1;

14:   sat_case4 = change satellite from case 2 to case 4;

15:   [case_selec, sat_selec] = compare case(case_selec, sat_selec, sat_case1, sat_case4);

16:  end

17:  if case_selec == 4

18:   sat_case1 = change satellite from case 4 to case 1;

19:   [case_selec, sat_selec] = compare case(case_selec, sat_selec, sat_case1);

20:  end

21:  return sat_selec, case_selec

22: end function changing uniform satellite

23:

24: void function compare case(case_selec, sat_selec, sat_caseA, sat_caseB, …)

25:  flag_case = compare minimum HDOP(sat_selec, sat_caseA, sat_caseB, …);

26:  switch flag_case

27:   case case_selec

28:    return sat_selec, case_selec

29:   case A

30:    sat_selec = sat_caseA;

31:    case_selec = A;

32:    return sat_selec, case_selec

33:   case B

34:    …

35:  end

36: end function case selection