General method for extracting source distance information from any kind of received radiation, including electromagnetic and acoustic, without involving round-trip time or phase in any form, and thus more truly passive than existing passive radars. The method exploits the facts that radiation from a real source must comprise wavepackets of nonzero bandwidth, that the individual frequency components of a wavepacket must have consistent phase at the source, and that their instantaneous phases must...

Scannerless loss modulated flash color range imaging methods and apparatus are disclosed for producing three dimensional (3D) images of a target within a scene. Apparatus and methods according to the present invention comprise a light source providing at least three wavelengths (passbands) of illumination that are each loss modulated, phase delayed and simultaneously directed to illuminate the target. Phase delayed light backscattered from the target is spectrally filtered, demodulated and image...

An apparatus for determining various physical quantities such as temperature, pressure, stress, strain, distance and the like in a manner such that a change in the physical quantity of interest results in a measurable change in the frequency of oscillation of a signal generated within the apparatus.

An optical backscatter filter (10) for use with continuous wave laser radar systems. The filter removes undesired frequency components corresponding to optical backscatter from a received input signal (12) to extract a desired return signal (32) associated with a target. The received signal (32) is processed optically, requiring only an electronic notch filter (24) and one electronic mixer (30) to finally extract the desired return signal (32).

The invention is a method for obtaining a measure of the light propagation time difference for two light-propagating-media paths. The first step consists of generating two substantially-identical frequency-modulated light waves whereby the frequency of the light waves is offset from a reference frequency by a different frequency increment for each basic time interval in each of a plurality of groups of three or more basic time intervals. Each frequency increment is the sum of a specified increme...

The purpose of this invention is a laser speed measurement and range finding device, with coherent detection comprising: a microlaser (10) with continuous emission comprising an active laser medium (10) and a microlaser cavity (16, 18), means (20, 22, 24) for modulating an optical frequency of a beam output by the microlaser, means (28) of outputting a signal depending on: firstly, the Doppler frequency ##EQU1## where .lambda. is the microlaser emission wave length and V is the speed of the targ...

An apparatus is provided for use in optically determining distance and velocity relating to an object. The apparatus includes an optical radiation source that emits a first optical radiation signal of a modulating amplitude. The amplitude modulation of the first optical radiation signal is swept over a predetermined frequency range in a predetermined time period. Common optical components are employed to direct the first optical radiation signal towards the object, and to receive a portion of th...

An apparatus is provided for use in determining the distance and velocity of a distant object. The apparatus employs a low energy optical radiation source that emits identical external and internal radiation signals whose wavelengths are swept. The wavelength sweep is induced by varying the magnitude of an electrical input supplied to the optical radiation source. An external ranging system employs common optical means, including polarizing means, to direct the external signal towards a distant ...

A laser radar detection system (10) is provided for detecting targets located within a detection field and discriminating between unresolved and resolved detected objects (32,34). The detection system (10) employs a laser radar sensor (12) for transmitting a frequency modulated optical transmit signal (22) which scans a desires field and receiving a return signal (24) from objects located therein. The laser radar sensor (12) includes a photo mixer (20) for providing the difference between the re...

Optical detection apparatus is provided which includes a coherent light sce for generating a beam of coherent light. The apparatus further includes a unitized or discrete optical component which receives the generated beam, and projects light thereof which has a particular polarization characteristic into a specified environment. The optical component also functions to receive or absorb light from the environment which has the particular polarization characteristic, and to directably reflect lig...