David E Hull

US Patent:

52258947, Jul 6, 1993

Filed:

Dec 5, 1991

Appl. No.:

7/802552

Inventors:

James E. Nicholson - Austin TX
Jack H. Parker - Kettering OH
Jagdish P. Mathur - Austin TX
David M. Hull - Austin TX

Assignee:

Tracor Aerospace, Inc. - Austin TX

International Classification:

G01J 351

US Classification:

356419

Abstract:

An incriment optical signal from a potential enemy threat is captured by an array of apertures which are connected to a number of broadband filters. The broadband filters have overlapping band pass regions to cover the wavelength spectrum of potential threats, but not with the spectral resolution of a larger number of narrowband filters. To further increase resolution without adding additional filters, each broadband filter is connected to an optical delay line which converts wavelength into a time delay. To enable measurement of the time delay, additional optical lines with no relative delay are connected directly from the apertures. The time difference between when a signal arrives over optical delay lines from the filters and when a signal arrives over optical lines directly from the array of apertures is then reconverted to wavelength to a high degree of resolution.