Table 1: Values of ai coefficients for different incidence angle α values.

α

a1

a2

a3

a4

a5

15°

-0.01026

-0.02117

-0.14181

0.99735

-0.83478

21.5°

-0.04207

0.01456

0.04714

-0.18583

0.24234

25°

-0.05686

0.03254

0.07334

-0.3597

1.4681