Woyk E
Appl Opt. 1978 Jul 1;17(13):2108-13. doi: 10.1364/AO.17.002108.
The new ray tracing theory, deduced from geometrical optics and widely developed for radio propagation in cosmic atmospheres, is now applied to optics. This paper is confined to the duct mode propagation which represents a singularity. A narrow horizontal beam emitted inside the waveguide can propagate a long path around the earth with very good periodic focusing: the central circular path coincides with the stratification of the atmosphere while rays above or below it are more or less curved. Perfect symmetry is not needed; but two specific conditions must be satisfied, and their occurrence just coincides with conditions under which mirages occur: a quiet mirage with sharp contours, evidently not much affected by scatter, occurs only during a temperature inversion, above a large hot desert, above a hot rather convex asphalt road, or (under convenient conditions) above a quiet level sea, which means only when favorable conditions establish the very sporadically occurring waveguide. A density maximum need not occur at all.
从几何光学推导出来并在宇宙大气中无线电传播方面得到广泛发展的新射线追踪理论，现在被应用于光学领域。本文仅限于讨论代表一种奇异情况的管道模式传播。在波导内部发射的窄水平光束能够沿着围绕地球的长路径传播，并具有非常好的周期性聚焦：中心圆形路径与大气分层重合，而其上方或下方的光线或多或少会发生弯曲。并不需要完美的对称性；但必须满足两个特定条件，而它们的出现恰好与海市蜃楼出现的条件相符：轮廓清晰的平静海市蜃楼显然受散射影响不大，仅在温度逆温期间、大型炎热沙漠上方、炎热且相当凸起的柏油马路上方或（在适宜条件下）平静的海平面上方出现，这意味着只有当有利条件形成非常偶尔出现的波导时才会发生。根本不需要出现密度最大值。
