Zenith Electronics Corporation

Recon/optical, Inc.

John A Lund

Stephen R Beran

Andre G Lareau

Ronald L Forbes

Brian O James

James P Quinn

William R Pfister

Dennis E Burke

Harold E Mann, Iii

An aerial reconnaissance system generates imagery of a scene that meets resolution or field of view objectives automatically and autonomously. In one embodiment, a passive method of automatically calculating range to the target from a sequence of airborne reconnaissance camera images is used. Range information is use for controlling the adjustment of a zoom lens to yield frame-to-frame target imagery that has a desired, e.g., constant, ground resolution or field of view at the center of the image despite rapid and significant aircraft altitude and attitude changes. Image to image digital correlation is used to determine the displacement of the target at the focal plane. Camera frame rate and aircraft INS/GPS information is used to accurately determine the frame to frame distance (baseline). The calculated range to target is then used to drive a zoom lens servo mechanism to the proper focal length to yield the desired resolution or field of view for the next image. The method may be performed based on parameters other than range, such as aircraft height and stand off distance.

Autonomous electro-optical framing camera system with constant ground

An electro-optical area array reconnaissance detector is disclosed which accomplishes forward motion compensation electronically and without moving parts. The array is made of photo-sensitive cells arranged in rows and columns, the columns being organized into one or more column groups. Charge packets collected in the cells representing scene information are transferred down the columns at the same rate as the image motion in the plane of the array. In a side oblique reconnaissance scenario, the columns may be organized into 16 column groups, each column group having its own charge transfer rate corresponding to the image motion rate in that column group.

Electro-optical imaging array with motion compensation

A two channel audio scrambling circuit for a television signal encoding system includes synchronized digital carrier switching means for deriving two suppressed carrier, switched audio signals that are 90 degrees apart, and combining them into a single output signal. A digital phase shifter, supplied with a carrier related to the horizontal line frequency develops properly phased outputs for controlling electronic switches to produce two phase displaced digital carrier switching signals. A plurality of scrambling modes are determined by logic means under control of a vertical interval signal, a video inversion signal and a tone signal input for controlling the digital phase shifter to change the carrier frequency. Complementary decoding circuitry for recovering the so-encoded audio signals is also described.

Two channel audio scrambling system

A multi-mode audio scrambling system includes an all-pass filter and a 90 degree phase shift circuit for supplying balanced modulators with 90 degree phase displaced audio information and 90 degree phase displaced carriers derived from the horizontal line frequency of a television receiver for producing a single sideband, suppressed carrier audio spectrum. A plurality of offset frequencies are derived from the horizontal line frequency and are used to further modulate the resultant signal to produce a single sideband displaced audio spectrum. A logic circuit selects the offset frequency (mode) in response to vertical interval signals, video inversion signals and audio tone or data signals. The final output is thus scrambled in different modes with different offset frequencies. A complementary unscrambling system is also described.

Dynamic audio scrambling system

A cable converter produces a 4.5 MHz intercarrier sound signal from a received television signal for application to one input of a phase lock loop circuit, the other input of which is supplied from a voltage controlled oscillator producing a regenerated 4.5 MHz intercarrier signal. The output of the phase lock loop is supplied through a loop filter to the input of the voltage controlled oscillator to control its frequency. The regenerated 4.5 MHz intercarrier signal is thus stabilized by the received 4.5 MHz intercarrier signal.

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McHenry, IL, United States of America

John A Lund