1983 年 1983 巻 42 号 p. 31-43
A major problem with the Instrument Landing System (ILS) Glide Slope is the dependence of performance on the terrain condition, since the Glide slope utilizes the ground image. Deep snow elevates the effective ground level and affects its performance.
The relations of snow depth and the Glide Slope performance were measured for two types of ILS Glide Slopes, i.e., the Null reference system and the Capture effect system, with a 55 m high far field monitor at the new Akita airport.
The results show that (1) the Null reference path angle increases at a rate of 0.021 degree per 10 cm of snow and the path width increases at a rate of 0.025 degree per 10 cm, (2) the Capture effect path angle increases at a rate of 0.025 degree per 10 cm of snow and the path width decreases at a rate of 0.011 degree per 10 cm, and (3) the Near field monitor is about 3 times as oversensitive as the far Bureau.