Sanders Associates Limited

Bae Systems Information and Electronics Systems Integration Inc.

Victor A Misek

Jacob Schwartz

Albin A Hastbacka

Donald S Young

Robert J Beairsto

Alphonse J Trasatti

Pulse integration is utilized on board an optically guided missile or other ordinance device used as a part of a target designation system for extending the lock-on range of the missile by approximately 18%, when a double pulse laser is utilized to illuminate and designate the target. Pulse integration is accomplished with a recirculating delay unit which superimposes the first pulse on the second pulse, such that while the pulses add coherently, noise does not add in phase. The pulse integration technique therefore enhances the signal-to-noise ratio when the missile is at the outer limits of its operating range. When the missile is sufficiently close to the target, doublet decoding is actuated to offer countermeasure resistance. At this point, pulse integration may proceed in lieu of doublet decoding or may be dispensed with in view of the increased signal-to-noise ratio due to the close range of the missile to the target.

Extended range, light weight laser target designator

An adcock DF-on-the-fly type direction finding system employing a beam forming dispersive delay line (BFDDL). A square array of four elements A1, B1, C1, and D1 with A1, C1 and B1, D1 being the diagonal pairs is used to input signals to combiner, shifter and summer elements to produce signals representing S.sub..phi. =A1+B1+C1+D1 and S=(B1-D1)+[(A1-C1) shifted -90.degree.]. S.sub..phi. and S are input to the BFDDL which produces output signals sampled from the output spatial interference pattern of the BFDDL at 90.degree. intervals. The output signals from the BFDDL are used to calculate the arrival of the signal of interest as being substantially equal to the phase shift between S.sub..phi. and S.

Direction finding system

A system for locating man-made specularly reflecting objects amongst non-specular surroundings such as foliage includes apparatus to initially project orthogonally polarized laser pulses towards a given area and to then detect returned laser pulses which are polarized, while rejecting randomly polarized radiation returned from non-specular objects. In one embodiment, specularly reflecting objects are detected by providing two detectors, each sensitive to light of a different polarization, and by differentially summing their outputs to reject randomly polarized incident light.

Polarization coded doublet laser detection system

A high speed, two dimensional phase gradient map of atmosphere-induced phase gradients measures the distortion of an optical beam transmitted through the atmosphere. This is accomplished by detecting phase gradients of an interference pattern produced by optically heterodyning a returned glint from a remote target with a portion of the transmitted beam. The phase gradients are utilized to assign conjugate corrective phase distortion values to COAT actuators to alter the phase structure of the waves at the transmitter aperture. In one embodiment, two interference patterns are formed with one pattern phase shifted by 90.degree. with respect to the other. The phase gradients and their direction are detected as a function of position across the transmitter aperture by the use of two optical scanners driven in synchronism to scan the respective interference patterns. An electrical phase shifter is used in one channel along with sum and differencing units and an up-down counter to detect both the amplitude and direction of the phase gradients. This information is used to position wavefront correcting mirrors in the transmitter aperture to cancel out atmospheric distortion by properly predistorting the transmitted beam.

Non-segmented phase gradient detector for coat system

A display employing a horizontal and vertical grid of parallel infrared light beams in front of a cathode ray tube (CRT) face wherein a finger or other object may be placed against the face of the CRT to mark a spot thereon and the spot so marked will be detected by the interrupted beams. Infrared sources and detectors are located around the periphery of the CRT face and operate in different planes to more closely follow the curvature of the CRT face and thereby minimize parallax errors.

Touch entry interactive cathode ray tube arrangement

A method and apparatus are provided for increasing the heat transfer efficiency of a heat exchanger by utilizing a high intensity RF field. Either an ion stream generated by the RF field or the RF field itself results in the efficiency increase and the rate at which the fluid acquires energy from the heat exchanger is enhanced to the extent that the boundary layer normally present at the walls of the heat exchanger which impedes the transfer of heat from the heat exchanger to the fluid breaks down during this process. The RF technique is utilized in one unique application for increasing the efficiency of solar energy receiver which operate at temperatures exceeding 1,500.degree. F in that the system eliminates arcing which would occur due to the high temperatures involved, if electrostatic (D.C.) ion spray devices were used. Arcing elimination is achieved both by the use of RF energy and by shielding the RF electrode or probe from contact with the heat transfer fluid with a dielectric member through which the RF field penetrates. In one embodiment a broad spectrum high voltage RF signal is generated by a Tesla coil to produce the RF signal. Alternatively, pulsed high RF energy of a single frequency may be used. This energy may be generated by a conventional magnetron and may be transmitted by a wave guide with a reentrant cone at the front of the solar receiver so that both focused solar energy and the RF energy impinge on the heat exchanger from the same direction.

Method and apparatus for increasing heat transfer efficiency

Pulse stretching and smearing due to forward scatter of a collimated beam from a light source is eliminated by the use of a multiple field of view detector which divides up the beam in the vicinity of the receiver into segments along the optical path of the beam, inverts the order of the signals from the segments, and delays the signals by predetermined amounts such that pulses from different segments overlap and add, with the delay set to compensate for different path lengths between the transmitter and the receiver due to the intercepting of various segments along the optical path by the fields of view of the individual detectors making up the multiple field of view receiver.

Optical communications forwards scatter compensator

Distance measurement is provided by an optical system which includes modulation detection apparatus for determining when the optics are a predetermined distance from an object. This is accomplished by detecting an in-focus condition in terms of the modulation content of a cross-correlated signal. When the device is used as a fuse, a fire control signal is initiated when the ordinance device carrying the fuse is at a predetermined distance from a target. The system includes a stationary cross-correlation grating set at an optimal single spatial frequency based on the resolution and more specifically the modulation transfer function of the optics used. The grating is located at the image plane of an optical imaging system and an optical wedge is mounted for rotation about optical axis of this system so that the image is circularly nutated in the plane of the cross-correlation grating. Light passing through the cross-correlation grating is directed to a detector whose output is then amplified, filtered and rectified to yield a signal proportional to the modulation content of the output signal from the detector, with 100 percent modulation indicating an in-focus condition. This signal is compared, in one embodiment, to the output of a second detector which establishes an adaptive threshold such that when this threshold is exceeded an alarm or fire control signal may be initiated. The threshold level corresponds to a modulation percentage indicative of an acceptable in-focus condition. The cross-correlation grating in a preferred embodiment takes on the form of a multi-apertured disc with the apertures arranged at the apices of a hexagonal pattern.

Growing community of inventors

Hudson, NH, United States of America

Victor A Misek