This invention employs a magnetometer as a magnetic heading reference for a vehicle such as a small aircraft. The magnetometer is mounted on a directional dial in the aircraft in the vicinity of the pilot such that it is free to turn with the dial about the yaw axis of the aircraft. The invention includes a circuit for generating a signal proportional to the northerly turning error produced in the magnetometer due to the vertical component of the earth's magnetic field. This generated signal is then subtracted from the output of the magnetometer to compensate for the northerly turning error. VISUAL ACCOMMODATION TRAINER-TESTER NASA Case No. ARC-11,426-1 Address inquiries to: Ames Research Center Corresponding to U.S. Patent Application No. 526,741 Filed 8-26-83 This invention relates to a device for training of the human visual accommodation system. Specifically, the device is useful for training a person to volitionally control his focus to his far point (normally infinity) from a position of myopia due to functional causes. The functional causes could be due, for example, to a behavioral accommodative spasm or the effects of an empty field. The device may also be used to measure accommodation, the accommodation resting position and the near and far points of vision. The components may be packaged in a very small volume. It is possible, for instance, to helmetmount the device for human engineering investigations involving piloting aircraft, driving cars, operating computer terminals and so forth. A spin stabilized satellite has an electronically despun antenna array comprising a multiplicity of peripheral antenna elements. A high gain energy beam is established by connecting a suitable fraction or array of the elements in phase. The beam is steered or caused to scan by switching elements in sequence into one end of the array as elements at the other end of the array are switched out. The switching transients normally associated with such steering are avoided by an amplitude control system. Instead of abruptly switching from one element to the next, a fixed value of power is gradually transferred from the element at the trailing edge of the array to the element next to the leading edge. Thus as the satellite rotates, power is reduced on one element and power is increased on the other element thereby avoiding switching transients and maintaining constant total array power at all times. *U.S. patent rights waived to Philco Ford Corporation, Union Meeting Road, Bluebelle, PA 19422. RECORDER/PROCESSOR APPARATUS NASA Case No. GSC-11553 Address inquiries to: Corresponding to U.S. Patent No. 3,781,902 Filed 9-7-71 Issued 12-25-73 This is an apparatus for recording and thermally processing data. A laser beam, modulated by a video signal generates a raster so as to expose a latent image of the input information on a storage medium. A rotating drum in conjunction with an incrementally driven lens carriage associated with the laser optical system provides the raster generation. The drum is automatically loaded with the storage medium from a supply means and automatically unloaded to a thermal processor upon completion of recording. The latent image is processed by the controlled application of heat so as to produce an actual displayable image corresponding to the data input at the output of the apparatus. The present invention is directed to a new parametric amplifier structure which exhibits a large gain-bandwidth product and low noise characteristics without cryogenic cooling. In addition, higher idler frequencies are attained and which are easily adjustable in resonant frequency. The amplifier includes a stacked pair of uncased varactor diode chips within a waveguide channel, which chips are stacked in a predetermined direction. |