Friend or foe identification system and method

Patent metadata

Field	Value
Publication number	US-9846235-B2
Application number	US-201314419954-A
Country	US
Kind code	B2
Filing date	Aug 8, 2013
Priority date	Aug 9, 2012
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

There are provided methods and systems for producing a wave-beam having substantially constant lateral extent over a desired range of distances, and interrogation and response system and methods utilizing the same. The method for producing a wave-beam having substantially constant lateral extent includes generating a plurality of at least partially incoherent constituent wave-beams having different divergences and directing the plurality constituent wave-beams to propagate along substantially parallel propagation axes such that the constituent wave-beams at least partially overlap and superpose to form a combined wave-beam. The divergences and intensities of the constituent wave-beams are selected such that the combined wave-beam has a desired substantially constant extent over a desired range of distances along said propagation axes.

First claim

The invention claimed is:

1. A method for producing a wave-beam having substantially constant lateral extent over a desired range of distances, the method comprising generating a plurality of at least partially incoherent constituent wave-beams having different divergences and directing the plurality constituent wave-beams to propagate along substantially parallel propagation axes such that the constituent wave-beams at least partially overlap and superpose to form a combined wave-beam, wherein said divergences and intensities of said constituent wave-beams are selected such that the combined wave-beam has a desired substantially constant lateral extent over a desired range of distances along said propagation axes.

2. The method of claim 1 , wherein said constituent wave-beams are emitted from one or more output apertures of dimensions significantly smaller than said desired substantially constant lateral extent, and wherein said one or more output apertures are arranged such that a distance between propagation axes of any two of said constituent wave-beams is significantly smaller than said constant lateral extent of the desired combined wave-beam.

3. The method of claim 1 , wherein said plurality of said constituent wave-beams are generated substantially simultaneously, either concurrently or sequentially within a time frame not exceeding a response time of a certain intensity detector.

4. The method of claim 1 wherein each two constituent wave-beams of said plurality of constituent wave-beams are produced with at least one of the following: having different wavelengths, having different polarizations, having different path lengths being on the order or greater than a coherence length, and produced at different times all within a time frame shorter than a response time of a certain detector; thereby resulting with said at least partial incoherence of said plurality of constituent wave-beams.

5. The method of claim 1 , further comprising adjusting the lateral extent of the desired combined wave-beam by controllably varying at least one of the divergence or intensity of at least one of the constituent wave-beams.

6. A wave-beam generator, comprising: a wave directing and focusing module adapted for receiving at least one primary wave-beam, and generating a plurality of at least partially incoherent constituent wave-beams having different divergences and directing the plurality of constituent wave-beams to propagate along one or more substantially parallel propagation axes such that the constituent wave-beams at least partially overlap and superpose to form a combined wave-beam, wherein the divergences and intensities of said constituent wave-beams are set such that the combined wave-beam has a desired substantially constant lateral extent over a desired range of distances along said propagation axes.

7. The wave-beam generator of claim 6 , comprising: at least one beam source adapted for providing said at least one primary wave-beam; and wherein said wave directing and focusing module comprises: at least one input coupled to the at least one beam source, one or more outputs, and an arrangement of one or more wave-affecting elements arranged to define a plurality of paths of different focusing powers in between said at least one input and said one or more outputs and configured and operable for producing, from said at least one primary wave-beam, said plurality of at least partially incoherent constituent wave-beams having the different divergences and directing them to output from said one or more outputs and propagate along said one or more substantially parallel axes and at least partially overlap to form a combined wave-beam.

8. The wave-beam generator of claim 7 , wherein said one or more outputs are associated with apertures of dimensions significantly smaller than said desired substantially constant lateral extent, and are arranged such that a distance between said propagation axes of is significantly smaller than said desired substantially constant lateral extent of the combined wave-beam.

9. The wave beam generator of claim 6 configured for producing one or more groups of constituent wave beams each group including up to four wave-beams having respective linear polarization along desired orientations, each orientation being at least at a 45 degree angle with a preceding orientation and a subsequent orientation; at wherein said different groups differing from one another in at least one of the following parameters: wavelength, polarization, and path length of their constituent wave-beams.

10. The wave beam generator of claim 7 , wherein properties of said at least one beam source and said one or more of optical modules are controllable enabling to controllably vary at least one of the following: intensity, divergence, of at least one of the constituent wave-beams, thereby enabling control over the lateral extent of the combined wave-beam.

11. An interrogation system comprising a wave beam generator configured according to claim 6 .

12. The system of claim 11 , further comprising a wave-beam generation controller adapted for selectively operating said wave-beam generator module for causing the generation of a desired interrogation wave-beam having a desired substantially constant lateral extent over a selected range of distances along a general direction of propagation of the interrogation wave-beam by concurrently producing respective constituent wave-beams of a selected combination of said combinations of the wave-beams selected such that superposition of the respective constituent wave-beams forms said desired interrogation wave-beam with the a desired lateral extent over the selected range.

13. The interrogation system of claim 12 comprising a target detection module comprising a interrogation wave-beam scanning module and adapted for sequentially operating said wave-beam generation controller for sequentially generating two or more interrogation wave-beams associated with at least one of different ranges and different lateral extents thereby enabling determination of a position of a responder system interrogated by one or more of the interrogation beams.

14. The interrogation system of claim 12 comprising an interrogation control module operative in accordance with a predetermined interrogation protocol and adapted for operating said wave-beam generator a to encode said interrogating wave-beam protocol with at least one of the following associated with said predetermined interrogation protocol:
a) an initialization sequence including series of initialization segments extending over a time duration greater than a predetermined standby time duration of a responder system to be interrogated, thereby enabling said responder system to identify said at least one of said initialization segments after recovering from a standby mode of duration not exceeding said standby time duration;
b) a synchronization data set encoded based on said predetermined interrogation protocol; includes data indicative of one or more of the following data fields:
i. end-of-initialization data field marking the end of an initialization sequence;
ii. authentication data field indicative of at least one of a type and identity of said interrogating system; and
iii. at least one communication data field indicative of a communication parameter to be used by said target responder system for communication of an acknowledgment response to said interrogation;

c) intensity measurement sequence that enables said responder to efficiently estimate the intensity of the interrogation wave-beam by utilizing varied amplification gains.

15. The interrogation system of

Assignees

• Israel Aerospace Ind Ltd

Inventors

• Aharoni Abraham
• Alon David Lou
• Yifrach Aharon

Classifications

• G01S7/484

  Transmitters · CPC title

• G01S7/52046

  Techniques for image enhancement involving transmitter or receiver (image enhancement by image data processing G06T5/00) · CPC title

• G01S17/08

  for measuring distance only (indirect measurement G01S17/46; active triangulation systems G01S17/48) · CPC title

• G01S13/04

  Systems determining presence of a target (based on relative movement of target G01S13/56) · CPC title

• H01Q21/29

  Combinations of different interacting antenna units for giving a desired directional characteristic (H01Q25/00 takes precedence) · CPC title