Abstract: The object of this invention is to reduce the adverse effects of reflected electromagnetic radiation on the measurement threshold of a scanning beam. It has particular application to the time reference scanning beam of the international microwave landing system (MLS). In the present MLS configuration, the reflection induced errors during the "TO" scan are additive to those of the "FRO" scan. This invention describes a method and apparatus for compensating errors by reversing the phase of the reflections during the "FRO" scan, by displacing the phase center of the transmitantenna during that scan. System performance is enhanced by the errors compensation.

Abstract: A dead reckoning navigation instrument, consisting of magnetically connected components, for navigation watercraft between known waypoints. A trackline on a transparent trackline plate connects the waypoints. A direction line on a transparent direction line plate, oriented perpendicular to the trackline is used to define the next waypoint along a route. A transparent overlay plate provides the speed and distance traveled scales for the dead reckoning navigation function.

Abstract: An ankle and foot exercise apparatus, in which a structure attached to the lower leg is a base plate having side supports that are attached to a rotatable support arm that is connected to one end of an elastic member, the other end of the elastic member being attached to a strap that encircles the ball of the foot. This elastic member, such as a surgical hose, causes a resistance to foot movement and ankle rotation, and thus the foot and ankle are exercised by moving those body parts against the resistance provided by the surgical hose. The attachment of this exerciser is facilitated by rotating the support arm relative to the side supports about a first bolt that is inserted and locked through a first set of aligned holes in support arm and in the side supports attaching the surgical hose to a rotatable support arm on the base plate. When the rotatable arm is rotated to a down position, this causes a slack in the surgical hose during attachment.