Correction is provided for errors in radial tracking and timing in a video disc playback system of the optical type. A large ring magnet, and a smaller ring magnet carrying a mirror on one face, are coaxially aligned with the smaller magnet supported on a universal pivot and held against its support by a magnetic field. Two pairs of electromagnets, responsive to error or correction signals, cause controlled tilting of the smaller magnet about two orthogonally related axes to maintain tracking re...

A tracking receiver for automatically detecting and phase locking a satele beacon signal under fixed doppler and high rates of change of doppler. The receiver has a third-order tracking and acquisition loop that includes a cos-limited tangent phase detector which has a phase error range greater than .+-.120.degree..

1. A tracking system including: a device having means providing a surface on which light from a predetermined optical field may be focused, said means emitting electrons at each point of said surface in accordance with the intensity of light impinging thereon, an anode, and means for focusing electrons emitted from a small area of said surface on said anode; moving means for continuously changing in a predetermined manner the position of said small area of said surface from which emitted electro...

A tracking receiver particularly for use in the radar art for determining the frequency of Doppler signals in laser-Doppler flow probes includes a voltage-controlled oscillator the control voltage of which is varied during search operations until the frequency of the converted input signal comes to lie in the band pass of an intermediate frequency stage and so produces in a frequency discriminator a regulating voltage for the voltage-controlled oscillator and with a threshold-value logic control...

A tracking apparatus for tracking an imaging object, includes: imaging means for imaging the imaging object; driving means for driving the imaging means to perform panning and tilting; position detection means for detecting a position of the imaging object in an image outputted from the imaging means; automatic tracking means for calculating a displacement amount between the position of the imaging object detected by the position detection means and a reference position in the image outputted fr...

Biasing means are coupled to a radiation responsive, variable impedance detector element to provide a swept sensing apparatus for producing an indication of the presence and location of a remote source of radiation or target without mechanically moving parts.

A conical scan signal receiver using digital computation apparatus for calculating angle tracking data is disclosed. The angle tracking data of a selected target are digitally calculated by determining the relative level of target related energy between an "up" elevation channel, a "down" elevation channel, a "right" azimuthal channel and a "left" azimuthal channel.

An apparatus for locating a large number of cooperative targets consisting of a ground-based master station, three airborne repeaters and as many transponder units as there are cooperative targets. The master station transmits pulses, which are received by the repeaters. The repeaters in turn transmit the pulses at a second frequency. The transponders and the repeaters transmit back to the master station. By accurately measuring the time required for the pulses from the transponders and repeater...

The invention provides a tracking apparatus and a tracking method by which an imaging object can be set without any special manual operation by a user. An imaged image is supplied to an imaging object setting section via an imaging object processing section. In the imaging object setting section, a motion detection section calculates a difference value between images of successive two frames and detects a motion of an image based on the difference value. Then, a portion of the image from which t...

An elongated sheet transport and guidance system including a drive roller mounted for rotation on a frame and adapted to engage and frictionally drive the sheet along its longitudinal axis and a pinch roller engaging the drive roller and mounted for rotation on an axis parallel thereto, the pinch and drive rollers being arranged to straddle and exert a pressure on that portion of the sheet passing therebetween. Also included in the system is a first means for inducing a first pressure level betw...