摘要:
Disclosed is a northfinding apparatus having a single rotation rate sensor secured to a platform. The output of the rotation rate sensor is corrected for tilt and tilt rate of the platform. Measurements of the tilt and tilt rate and the rotation rate are combined to provide an azimuth angle of the platform relative to north.
摘要:
The present invention provides a discriminant signal apparatus for providing a discriminant signal indicative of the lock-in rate. The discriminant signal apparatus of the present invention is responsive to the behavior of the instantaneous phase difference between the waves, and specifically the behavior of the phase difference occurring substantially about, both before and after, occurrences of the first derivative of the phase difference having substantially zero value.
摘要:
An electromagnetic system for determining the orientation including position of a helmet worn by a pilot is disclosed, having a transmitting antenna for transmitting electromagnetic field vectors, a receiving antenna for sensing the electromagnetic field vectors, a control apparatus responsive to the sensed electromagnetic field vectors and the transmitted electromagnetic field vectors for determining the orientation including location of the helmet, the control apparatus having a first output for supplying the orientation to a utilization apparatus and a second output, a driver for supplying driving energy to the transmitting antenna coils, and a selector switch connected to the second output of the control apparatus and to the driver for sequentially energizing the coils of the transmitting antenna.
摘要:
Apparatus and method for the surveying of bore holes, for example, oil wells and the like, to permit accurate three-dimensional mapping thereof, using an accelerometer package in an instrumentation pod which is lowered into the bore hole. In one embodiment the pod is lowered on the end of a rod string where adjacent rods connected together with Hookes-joint pivots which permit two degrees of freedom of movement between adjacent rods. In another embodiment, rigid interconnections of adjacent rods are used, and the rods are isotropic for twistless flexure as the rods encounter curves in the path of the bore hole. The instrumentation pod is lowered one rod-length at a time, and accelerometer readings are taken which, together with mathematical modeling of rod motion, permits calculation of updated pod position at all depths in the hole.
摘要:
A discriminant apparatus for laser angular rate sensors which provides an output signal related to a selected weighted vectorial sum of the coupling of energy between counterpropagating waves traveling about a closed-loop path. The discriminant apparatus is utilized in a closed-loop control system for minimizing the lock-in rate of the sensor and/or maintaining and selecting scale factor linearity.
摘要:
The present invention provides a method and apparatus for removing systematic distortion from measurements of an observable parameter. The method and apparatus of the present invention is particularly useful for removing systematic distortion in phase angle measurements of ring laser angular rate sensors.
摘要:
A data projection system in which a data projector having a data display memory associated therewith projects images to a viewing screen. The system includes a curved or nonplanar viewing screen and computer software effective to provide viewing fidelity by compensating for inaccuracies of the viewing screen.
摘要:
A path length control for a ring laser is described which captures a true peak power laser mode in the presence of parasitic secondary power modes. The control utilizes a decaying dither of the optical path length which decays from a large initial dither amplitude.
摘要:
A discriminant apparatus for a ring laser angular rate sensor is described which provides a discriminant signal indicative of the lock-in rate of the sensor as a function of the phase difference and frequency difference between the counter-propagating waves therein.