The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Oct. 03, 2017

Filed:

May. 06, 2014
Applicant:

Raytheon Company, Waltham, MA (US);

Inventor:

James W. Rakeman, Brea, CA (US);

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N 21/27 (2006.01); F02K 9/08 (2006.01); G01S 13/58 (2006.01); G01N 21/71 (2006.01); G01J 3/433 (2006.01); F41H 11/02 (2006.01); G01S 13/72 (2006.01); G01S 13/86 (2006.01);
U.S. Cl.
CPC ...
G01N 21/71 (2013.01); F02K 9/08 (2013.01); F41H 11/02 (2013.01); G01J 3/433 (2013.01); G01N 21/27 (2013.01); G01S 13/58 (2013.01); G01S 13/72 (2013.01); G01S 13/86 (2013.01); G01N 21/716 (2013.01); G01N 2201/12 (2013.01);
Abstract

Pressure variations within a solid propellant rocket motor produce like variations in the optical radiance of the motor exhaust plume. The periodicity of the variation is related to the length L of the rocket motor or speed of sound in the rocket motor combustion chamber to length ratio a/L. The optical radiance is collected and converted to electrical signals that are sampled at or above the Nyquist rate. An array of single-pixel photo detectors is well suited to provide amplitude data at high sample rates. The sampled data from the one or more detectors is assembled to form a high fidelity time sequence. A window of sampled data is processed to form a signal frequency spectrum. The mode structure in the frequency spectrum is related to the rocket motor length or speed of sound in the rocket motor chamber to length ratio. The rocket motor length or speed of sound to length ratio is used alone or in combination with other information to either classify or identify the rocket motor.


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