Percent Integrated Gradient Field Ratio for hardat.ru2 at radius 0.0175 m. 
  where Integrated Gradient Field Ratio = Sum[(abs(Bn/B2*sin(-n*theta_south_pole ))] for harmonics 3-16  

    Imag        Integrated Gradient Field Ratio 
    (A)                         %                 
  ---------     ----------------------------------  
  46.90134                    1.78694
 149.99032                    1.86996