Elimination of frequency shift in a multiplex communication system Patent

Multiplexed communication system design including automatic correction of transmission errors introduced by frequency spectrum shift

High speed phase detector Patent

High speed phase detector design indicating phase relationship between two square wave input signal

Hydraulic system provides smooth control of large tracking and antenna drive systems at very low tracking rates

Hydraulic system provides smooth control of large tracking and antenna drive systems at very low tracking rates. This configuration modifies a series connection of the drive motors with compensating orifices to offset the effects of drain line loss. Linearization of response by eliminating cogging or cyclic operation is thus obtained

Safe-arm initiator Patent

Electroexplosive safe-arm initiator using electric driven electromagnetic coils and magnets to align charg

Wakes and differential charging of large bodies in low Earth orbit

Highlights of earlier results using the Inside-Out WAKE code on wake structures of LEO spacecraft are reviewed. For conducting bodies of radius large compared with the Debye length, a high Mach number wake develops a negative potential well. Quasineutrality is violated in the very near wake region, and the wake is relatively empty for a distance downstream of about one half of a Mach number of radii. There is also a suggestion of a core of high density along the axis. A comparison of rigorous numerical solutions with in situ wake data from the AE-C satellite suggests that the so called neutral approximation for ions (straight line trajectories, independent of fields) may be a reasonable approximation except near the center of the near wake. This approximation is adopted for very large bodies. Work concerned with the wake point potential of very large nonconducting bodies such as the shuttle orbiter is described. Using a cylindrical model for bodies of this size or larger in LEO (body radius up to 10 to the 5th power Debye lengths), approximate solutions are presented based on the neutral approximation (but with rigorous trajectory calculations for surface current balance). There is a negative potential well if the body is conducting, and no well if the body is nonconducting. In the latter case the wake surface itself becomes highly negative. The wake point potential is governed by the ion drift energy

Inflight IFR procedures simulator

An inflight IFR procedures simulator for generating signals and commands to conventional instruments provided in an airplane is described. The simulator includes a signal synthesizer which generates predetermined simulated signals corresponding to signals normally received from remote sources upon being activated. A computer is connected to the signal synthesizer and causes the signal synthesizer to produce simulated signals responsive to programs fed into the computer. A switching network is connected to the signal synthesizer, the antenna of the aircraft, and navigational instruments and communication devices for selectively connecting instruments and devices to the synthesizer and disconnecting the antenna from the navigational instruments and communication device. Pressure transducers are connected to the altimeter and speed indicator for supplying electrical signals to the computer indicating the altitude and speed of the aircraft. A compass is connected for supply electrical signals for the computer indicating the heading of the airplane. The computer upon receiving signals from the pressure transducer and compass, computes the signals that are fed to the signal synthesizer which, in turn, generates simulated navigational signals

The importance of wildlife rabies control

Rabies in animals has been known In North America for over two centuries, and whether the disease was initially present in wild species or was introduced by dogs, it has been known in skunks for almost a century and a half. Today more rabies cases in wild animals are reported than in domestic animals, and a considerable proportion of both human and domestic animal exposures to the disease are the result of wild-animal contact. The most useful techniques for controlling wild animal rabies today are methods that reduce contact between infected individuals and susceptible individuals; these involve the manipulation of populations, most often by direct reduction methods. Such techniques have proved effective in controlling or eliminating the disease; they are most effective when the area involved is small and/or isolated by barriers. The effectiveness of animal reduction programs on rabies is limited by the range of the animals involved, of ingress from surrounding areas for animals incubating the disease, and the continuity of the program; at least two maximum incubation periods of the disease must have elapsed as insurance that incubating animals are not left to serve as a new nucleus of infection. Rabies control programs for wild species have not yet threatened any species with extinction, nor are they likely to in the future

Calculation of sheath and wake structure about a pillbox-shaped spacecraft in a flowing plasma

A computer program was used for studies of the disturbed zones around bodies in flowing plasmas, particularly spacecraft and their associated sheaths and wakes. The program solved a coupled Poisson-Vlasov system of nonlinear partial differential integral equations to obtain distributions of electric potential and ion and electron density about a finite length cylinder in a plasma flow at arbitrary ion Mach numbers. The approach was applicable to a larger range of parameters than other available approaches. In sample calculations, bodies up to 100 Debye lengths in radius were treated, that is, larger than any previously treated realistically. Applications were made to in-situ satellite experiments