Course structure-runway 28R San Francisco Airport.

The TSC electromagnetic scattering model is used to dtermine the expected ILS localizer performance for the planned 28R runway at San Francisco airport. It is found that the V-Ring and the 14/6 Alford array as well as the larger 22/8 Alford array operating with a 10db "capture effect ratio, " do not produce an acceptable course meeting FAA Categor I tolerances. The feasibility and advantages of operating the Alford array at higher capture effect ratios is discussed. Based on a "worst case" airport enviroment, the maximum capture ratio obtainable with the Alford 22/8 array is calculated and shown to lead to a marginally acceptable Category I course structure. For an "ideal" airport environment it is possible to use high capture ratios with the result that Category I requirements are easily satisfied and Category II tolerances marginally so with the Alford 22/8 array. The course structure in each case has been calculated under the assumption that the derogator is a metallic perfect reflector.