Abstract: Radar tracking or homing units employing three or more primary radiators and utilizing an arrangement of a sum-difference network and signal processing stage to form sum, difference and cross-related or cross-term signals and to effect correction of errors introduced due to the presence or apparent presence of two targets with the resolvable radar volume, using a stipulated method of signal processing.

Abstract: An arrangement for correcting deviations from the true bearing due to the effects of specular reflecting surfaces in target tracking radar installations having at least three primary feeds. At least two of the primary feeds are aligned such that a plane formed by the longitudinal axes of their radiation characteristics is disposed at least approximately perpendicular to the specular reflecting surface. At least one further primary feed is arranged such that the longitudinal axis of its radiation characteristic is located externally of such plane. A summation-difference network produces from the echo signals received by the primary feeds, apart from a summation signal, also two difference signals, and a cross-term signal formed in at least one measurement interval. From these signals there is produced an angle error signal which is divided into two components.

Abstract: A closed circuit hydraulic control system for an hydraulic motor including a cylinder, a piston movable in such a cylinder, and a rod connected to one side of the piston, such cylinder having a blind end and a rod end through which the rod extends. A reversible circulating pump having two ports is provided for supplying fluid under pressure to the blind end and to the rod end respectively of the cylinder. A first tubing interconnects the blind end of the cylinder to one port of the reversible pump, whereas a second tubing interconnects the rod end of the cylinder to the other port of the reversible circulating pump. Means are provided to accommodate the volume of fluid displaced by the rod as the piston is moved toward the blind end of the cylinder.