Laser detection of explosive residues

• US 5,760,898 A
• Filed: 01/08/1997
• Issued: 06/02/1998
• Est. Priority Date: 01/08/1997
• Status: Expired due to Fees

• Current Assignee: IDS Intelligent Detection Systems Incorporated
• Original Assignee: IDS Intelligent Detection Systems Incorporated
• Inventors: Thekkadath, Govindanunny, Haley, Lawrence V.
• Primary Examiner(s): Evans, F. L.
• Application Number:
  US08/778,236
• Time in Patent Office: 510 Days
• Field of Search: 356/317, 356/318, 356/417
• US Class Current: 356/318
• CPC Class Codes: G01J 2003/2866 Markers; Calibrating of scan
• CPC Class Codes: G01J 3/457 Correlation spectrometry, e.g. of the intensity G01J3/453 takes precedence
• CPC Class Codes: G01N 21/631 using photolysis and investigating photolysed fragments
• CPC Class Codes: G01N 33/227 Explosives, e.g. combustive properties thereof

Abstract

A laser is used in the detection of explosives residue by creating micro-detonations of explosive particles adhered to objects. An object is scanned with a beam of coherent laser light to induce micro-detonations of micro-particles of explosive residue adhered to the object. Temporal and spectral information representative of light emitted by the micro-particles is used to characterize the explosives.

Claims

1. An apparatus for laser detection of micro-particles of explosive residue on the surface of an object to be inspected, said apparatus comprising:

(a) a laser for generating a beam of coherent light;

(b) optical means for scanning an object to be inspected with said beam of coherent light to induce micro-detonations of said micro-particles of explosive residue;

(c) a detector means for sensing temporal and spectral information of light emitted from the impingement of said beam of coherent light on said object to be inspected during said scan and generating a data acquisition signal therefrom;

(d) data processing means for comparing said temporal and spectral information in said data acquisition signal with one or more empirically obtained patterns of temporal and spectral information derived from laser induced detonation of said microparticles of explosives;

(e) means for generating an alarm signal in the event said temporal and spectral information in said data acquisition signal matches one of said empirically obtained patterns.

2. A method of detecting micro-particles of explosive residue on an object to be inspected with a laser, said method comprising:

(a) generating a beam of coherent light;

(b) scanning an object to be inspected with said beam of coherent light to induce micro-detonation of said microparticles of explosive residue;

(c) sensing the temporal and spectral information of light emitted from the impingement of said beam of coherent light on said object to be inspected during said scan and generating a data acquisition signal therefrom;

(d) comparing said temporal and spectral information in said data acquisition signal with one or more empirically obtained patterns of temporal and spectral information derived from laser induced detonation of said micro-particles of explosives;

(e) generating an alarm signal in the event said temporal and spectral information in said data acquisition signal matches one of said empirically obtained patterns.