Abstract: A bistatic passive radar system is used in conjunction with a host transmitter that is a determinable distance D from the radar system for determining the distance D and for displaying video images of a selected target, the position of the radar system and the position of the transmitter on a display. The invention is characterized by a system and method of using the display to determine the slant range S and the altitude H of the selected target relative to the position of the radar system. Three alternative embodiments of the invention are disclosed.

Abstract: A bistatic passive radar system having a display; a first directional antenna for determining the angle between the reference azimuth of the bistatic passive radar system and the line of sight to a host transmitter; an omnidirectional antenna for receiving reflected radar pulses from targets at any bearing; and a second directional antenna for determining the angle B between the line of sight to the host transmitter and a second line which extends from the bistatic passive radar system to a selected target. The angle of the second directional antenna is indicated by a B cursor on the display. The system includes a bistatic range correction circuit that utilizes an empirical determination of the distance D between the bistatic passive radar system and the host transmitter for determining the correct range for display of a selected target.

Abstract: An active impulse magnetometer includes a magnetic field transmitter which generates a low frequency magnetic impulse waveform. A separate magnetometer receiver responds to the transmitted waveform, and produces a receive waveform which is transformed by a Fast Fourier Transform device into the frequency domain. The transformed signal is processed to indicate the presence of any detected objects.

Abstract: A system for scanning the interior of a cargo container includes a propagator device for producing a magnetic field at each of (I) positions adjacent a first side of a cargo container and a detector device for detecting magnetic field strength at each of (J) positions adjacent a second side. The (I) positions are spaced apart in a direction generally parallel to a Y axis of a Cartesian coordinate system and components are included for mapping information about magnetic field strength at each of the (J) positions for each of (K) positions of the cargo container as it passes between the propagator and detector devices in a direction generally parallel to an X axis. Spaced apart orthogonal propagator and detector elements may be disposed in vertical columns adjacent the cargo container, and computerized control components may be used to map and process the information and to produce and display an image.

Abstract: An imaging radar system for generating images of objects disposed behind an obscuring structure. The system comprises a low power, frequency tunable, continuous wave transmitter and an antenna array coupled to the transmitter that includes a transmit antenna and a plurality of receive antennas. A radar receiver is coupled to the antenna array, and a computer processor is coupled to the radar receiver that comprises a digital signal processor and a computer. A radar display is coupled to the computer for displaying the images of the objects disposed behind an obscuring structure. A power source is coupled to the antenna array, the transmitter, the radar receiver, and the computer processor for providing power thereto. Time difference of arrival processing is performed in the computer for providing radar angle scanning upon receipt of radar return signals from the objects using the antenna array.

Abstract: A motion detection radar system comprised of a low power frequency tunable continuous wave transmitter and antenna, a receiver, an FM transmitter and antenna, and a handheld remote FM receiver. The radar system may be adapted to operate at any frequency from 600 MHz to 1.2 GHz. The motion detecting radar system uses a technique for measuring the changes in phase difference and the rate of change of phase differences detected thereby. The receiver captures the total energy reflected from all reflective objects within the antenna field of view and compares that signal with the transmitted signal in a mixer. If all objects are stationary and the radar system is stationary, the total complex phase pattern of the return signal is constant, and a fixed DC output signal is provided from the mixer. Any motion within the field of view changes the fixed phase relationship and causes a phase rate of change at the receiver output.

Abstract: A three dimensional imaging radar system and method for generating and processing radar information to produce a three dimensional image of objects viewed by the system. The system is designed to create three dimensional images of physical objects at relatively short range, up to a distance of about 1000 feet. The radar system comprises a servo controlled antenna system, wherein the servo system provides azimuth and elevation pointing angle output signals. Two radar transmitters provide radar signals in two different radar bands that are selectively transmitted by the antenna system as a radar beam. A radar receiver preprocesses radar return signals reflected from targets.

Abstract: A bistatic passive radar system and method for airborne use in a first aircraft in conjunction with a host transmitter located in a second aircraft that may be at a different altitude than the first aircraft, characterized by a system and method for determining the distance between the aircraft. The system for determining the distance between the aircraft includes a system for receiving radar signals from the host transmitter directly and via reflection from a selected ground target located between the two aircraft; a system coupled to the receiver for determining the apparent range R.sub.a from the host transmitter on the second aircraft to the receiver on the first aircraft in response to receipt of the radar signals; a device on the first aircraft for determining the altitude H of the first aircraft; a device on the first aircraft for determining the angle .theta.

Abstract: The range corrector circuit uses two counters, one for the apparent range (R.sub.a) and one for the correct range (R.sub.c), and a random access memory (RAM). The R.sub.c counter is continuously incremented linearly and the R.sub.a counter is incremented in accordance with a range correction equation. Both counters are reset to one every time a transmitter pulse is received. A linear sweep is also initiated on the plan position indicator (PPI) display of the bistatic passive radar at that time. Target returns are entered into the RAM at the address specified by the R.sub.c counter and are read out of the RAM and applied to the PPI display at the address specified by the R.sub.a counter.