gcp                   package:Rsac                   R Documentation

_G_R_E_A_T-_C_I_R_C_L_E-_P_A_T_H _P_A_R_A_M_E_T_E_R_S

_D_e_s_c_r_i_p_t_i_o_n:

     Calculates the azimuth and back azimuth of the great-circle-path
     between two points (source and receiver) on a sphere.

_U_s_a_g_e:

     gcp(s, e)

_A_r_g_u_m_e_n_t_s:

       s: receiver, or station. This is a list with elements 'lat' and
          'lon' given in degrees. 

       e: epicenter, or source. This is a list with elements 'lat' and
          'lon' given in degrees. 

_V_a_l_u_e:

     a list containing the following elements: 

       C: azimuth, in degrees.

       B: back azimuth, in degrees.

       a: arc distance, in degrees.

     lat: latitude defining the path.

     lon: longitude defining the path.

_A_u_t_h_o_r(_s):

     Eric M. Thompson <eric.thompson@tufts.edu>

_R_e_f_e_r_e_n_c_e_s:

     Lay, T. and T. C. Wallace, (1995) _Modern Global Seismology_,
     International geophysics series; v. 58, San Diego: Academic Press.

