Anatoly L. Virovlyansky
Inst. of Appl. Phys., 46 Ulyanov St., 603600 Nizhny Novgorod, Russia
Some properties of ray arrival sequences valid in a waveguide with an arbitrary sound-speed profile are ascertained using the simple approximate formula connecting differences in ray travel times and adiabatic invariants of their trajectories. It is noted that the following conservation law takes place: The mean difference in travel times of rays having their launch angles inside the fixed narrow angular interval does not depend upon the distance between the source and the receiver. This law holds true not only in the range-independent waveguide but in the adiabatically varying waveguide as well. Some general conclusions concerning the relationship between travel times and launch angles of rays reaching the receiver are made.