POPHAM PANNEAU.
POPHAM PANNEAU.
“A PUFF.”
GROUND STRIPS.
If it be asked why the pilot does not receive as well as send wireless messages while in the air, it may be stated that up to the present the difficulties of receiving on a trailing aerial have been such that what might be termed a graphic ground method has proved preferable. Large ground strips are, on active service, an invitation for bombardment by the enemy and are being aided by the Popham Panneau, a method of signalling consisting of the rapid forming up of small, symmetrical, rectangular figures, by arrangements of white bands capable of rapid variation. In general they are the combination of the letter “T” with short, symmetrical additions.
The Aldis lamp, also used, is an improvement on the heliograph, and reflects the rays of an electric globe instead of sunlight, but it will be understood that recent advances in wireless telephoning have revolutionized the above methods.
A word is in place with regard to the Artillery Coöperation School at Leaside through which all pilots of necessity must pass. The equipment is the result of very brilliant work by an R.A.F. officer. The maps themselves represent two sections of the Western front, and are reproduced with vivid accuracy from aerial photographs. Each is 40 feet × 20 feet, and contains some eighty targets so arranged as to allow switching from one gun pit to another, thus following the actual work of destruction by imaginary batteries. Zone calls are arranged for all targets, these representing every possible point for bombardment, such as hostile battery positions, trench points, railroads, cross roads and fortified positions in enemy towns. British and German trenches are shown on a scale of approximately five inches to one hundred yards.
The total number of electric globes used to simulate bursts is 1,360, and the two balconies where the observing pilots sit are so equipped that every operation which must be carried out in doing wireless tests must be completed before signals can be received by the operator seated below at the imaginary battery. Space does not permit of a detailed description of the intricate, electrical work required to complete this admirable installation. It suffices to say that those best qualified to judge deem it a very considerable achievement.
Rotary targets are also used, as by turning them practically the same condition is created as that which confronts the pilot when turning his machine in the air. These, too, represent a reproduction of well-known sections of the Western front.