SYSTEM FOR DELINEATING SELECTIVE RESPONSE OF A MATERIAL TO RADIATION IN PRESENCE OF VISIBLE ILLUMINATION

• US 3,663,814 A
• Filed: 01/29/1969
• Issued: 05/16/1972
• Est. Priority Date: 01/29/1969
• Status: Expired due to Term

• Current Assignee: Andrew Madsen
• Original Assignee: Andrew Madsen
• Inventors: Madsen, Andrew
• Primary Examiner(s): Borchelt, Archie R.
• Application Number:
  US04/795,119
• Time in Patent Office: 1,203 Days
• Field of Search: 250/83.3UV,83.6S,83.3,83.3IR,71 356/151 128/2,2.1
• US Class Current: 250/253
• CPC Class Codes: G01N 21/64 Fluorescence; Phosphorescence
• CPC Class Codes: G01V 8/02 Prospecting
• CPC Class Codes: G03B 15/00 Special procedures for taking photographs; Apparatus therefor

Abstract

A pulsed visible illumination source illuminates a material to allow, for example, a helicopter pilot to fly over the surface of the earth in darkness. The visible light is interrupted to allow a pulsed ultraviolet source to stimulate luminescent reradiation from the material which reradiation is detected by observers and/or cameras. Both observers and camera are shielded by goggles or shutters so that the stimulated luminescence produced by the ultraviolet is not masked by the visible illumination. Such shutters are synchronized with the visible illumination pulses.

Claims

1. A system for delineating the selective response of a material in a dark environment to impinging ultraviolet radiation while visibly illuminating said material comprising, a first source of electromagnetic radiation including the visible range directed towards said material for visibly illuminating said material, said radiation having frequencies lying within a predetermined electromagnetic frequency spectrum, a second source of electromagnetic radiation including the ultraviolet range directed towards said material for causing said material to selectively reradiate electromagnetic energy in a spectrum which overlaps with said predetermined frequency spectrum or with reradiation from said material caused by said first source, means for intermittently interrupting said visible radiation from said first source tOwards said material, and means for receiving said selective reradiation from said material during said interruptions.

2. A system as in claim 1 together with means for shuttering said means for receiving said selective reradiation during periods when radiation from said first source is being directed toward said material.

3. A system as in claim 1 in which said material includes portions of the earth'"'"''"'"'s surface and said first and second sources are moved above said surface at a predetermined altitude.

4. A system as in claim 3 in which said first and second sources are attached to an airborne platform having a human pilot and said visible illumination allows said pilot to direct said platform.