Techniques for Computing Refraction of Radio Waves in the Troposphere

Book excerpt: Eight methods of computing atmospheric refraction of radio rays are discussed with appropriate theoretical background. These methods are: (1) The high-angle, or astronomical, refraction case; (2) The statistical method; (3) The low-angle, or terrestrial, refraction case (Schulkin's method); (4) The four-thirds earth model; (5) The exponential model; (6) The initial gradient correction method; (7) The departures-from-normal method; (8) A graphical method (Weisbrod's and Anderson's method). Sample computations are included for each of the above methods.