Systems and Methods for Illumination and Observation

• US 20150358556A1
• Filed: 02/25/2013
• Published: 12/10/2015
• Est. Priority Date: 02/24/2012
• Status: Active Grant

• Current Assignee: Karem Aircraft, Inc.
• Original Assignee: Karem Aircraft, Inc.
• Inventors: Karem, Abe, Tigner, Benjamin
• Granted Patent: US 9,871,979 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B64C 39/02 characterised by special use
• CPC Class Codes: B64D 47/08 Arrangements of cameras
• CPC Class Codes: B64U 10/00 Type of UAV
• CPC Class Codes: B64U 10/13 Flying platforms
• CPC Class Codes: B64U 20/87 Mounting of imaging devices, e.g. mounting of gimbals
• CPC Class Codes: B64U 2101/30 for imaging, photography or videography
• CPC Class Codes: H04N 23/00 Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 5/30 Transforming light or analogous information into electric information scanning details H04N3/00; cameras or camera modules comprising electronic image sensors, or control thereof H04N23/00; circuitry of solid-state image sensors [SSIS] or control thereof H04N25/00

Abstract

An aerial surveillance and reconnaissance system includes a gimbal-stabilized ISR imaging sensor with 0.8-1.2 microradian optical resolution, using pulsed ultraviolet laser (0.330-0.380 micrometer wavelength) radiation to illuminate the observed target, and a narrow-band-pass filter at the focal plane detector to remove light at frequencies other than the illuminating frequency. Preferred sensors can be operated in a snapshot mode using intermittent illuminating pulses, with timing of the pulses selected for minimum detectability based on observations made with a lower-resolution sensor, or in a video-mode with illuminating pulses selected to generate full-motion video at operator-selectable frame rates. Some sensor embodiments may further combine the UV system described above with conventional daylight optical and sensor systems, though alternative arrangements could also include an IR sensor as well (either using a common aperture with the UV system or with a separate set of light-gathering optics).

Claims

1. An aerial surveillance and reconnaissance system, comprising:

a primary optical system having a primary aperture, an incoming light path, and including at least three mirrors;

a first detector coupled to the incoming light path, having sensitivity to ultraviolet light, and behind an ultraviolet bandpass filter;

a second detector coupled to the incoming light path, having sensitivity to visible light;

a movable minor which can be commanded to direct light to either the first detector or the second detector; and

an ultraviolet laser illumination system capable of sending laser illumination out through the primary optical system.

2. The system of claim 1, further comprising a second optical system with a secondary aperture that is smaller than the first aperture.

3. The system of claim 2, where the primary optical system is mounted on a gimbal stabilization system, and the second optical system is mounted to the same gimbal stabilization system.

4. The system of claim 1, where the primary aperture is at least 400 mm.

5. The system of claim 1, further comprising a steerable minor coupled to the laser illumination system.

6. The system of claim 1, further comprising a deformable minor.

7. The system of claim 1, where the ultraviolet laser illumination system produces output having a wavelength of at between 0.330 and 0.380 micrometers.

8. The system of claim 1, where the bandpass filter passes at least 90% of light at a center wavelength between 0.350 and 0.360 micrometers, with a band width of between 0.008 and 0.012 micrometers.

9. A method of observing a target, comprising:

configuring an aerial platform with the system of claim 2;

using the second optical system to detect a target by imaging the target to a first angular resolution; and

using the primary optical system in conjunction with the ultraviolet laser illumination system to image the target to a second angular resolution which is finer than the first angular resolution

10. The method of claim 9, where the step of identifying the target is automated.

11. The method of claim 9, where the ultraviolet laser illumination system is operated to generate pulses of between 8 and 12 Joules of energy.

12. The method of claim 9, where the ultraviolet laser illumination system is operated to generate pulses of between 1.5 and 2.5 nanoseconds of duration.

13. The method of claim 9, further comprising operating the aerial platform at an altitude and a distance from the target.