Detecting device and method combining images with spectrums in ultra-wide waveband

Patent metadata

Field	Value
Publication number	US-9518867-B2
Application number	US-201514902271-A
Country	US
Kind code	B2
Filing date	Feb 10, 2015
Priority date	Dec 30, 2014
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

The invention discloses a detecting device combining images with spectra in an ultra-wide waveband, comprising a scanning rotating mirror, a Cassegrain mirror assembly, three spectroscopes, a reflector, four broadband lens assemblies, a visible and near-infrared lens assembly, a long wave lens assembly, a CCD imaging unit, an FPA imaging unit, a Fourier spectrum measuring unit and a grating spectrum measuring unit. The invention is able to recognize a target accurately by spectrum measurement under the guidance of a preliminary recognition process by imaging in visible, near-infrared and long wave infrared wavebands and can solve the problems of incomplete waveband imaging, restricted optical layout, large device size, and poor ability to detect moving objects and dynamic behaviors in prior art. The invention features small size, high integration and being convenient and flexible to use, and can realize image and spectrum detection of moving objects and dynamic behaviors in an ultra-wide waveband and switch a tracking and recognition process for different targets automatically and therefore can be widely used in national economy and national security.

First claim

What is claimed is:

1. A detecting device combining images with spectra in an ultra-wide waveband, comprising a scanning rotating mirror, a Cassegrain mirror assembly, a first spectroscope, a reflector, a first broadband lens assembly, a second broadband lens assembly, a third broadband lens assembly, a fourth broadband lens assembly, a second spectroscope, a third spectroscope, a visible and near-infrared lens assembly, a long wave lens assembly, a CCD imaging unit, an FPA imaging unit, a Fourier spectrum measuring unit and a grating spectrum measuring unit, wherein
said scanning rotating mirror is controlled by a servo motor to aim at a target area and operable for reflecting light from the target area to said Cassegrain mirror assembly, said Cassegrain mirror assembly is operable for collecting the reflected light and reflecting it to said first spectroscope, said first spectroscope is operable for transmitting infrared light of 2˜14 um to said first broadband lens assembly and reflecting infrared light of 0.4˜2 um to said reflector, said second spectroscope is operable for transmitting a portion of light of a first predetermined waveband to said long wave lens assembly and reflecting the residual portion of light of said first predetermined waveband and light of the residual waveband to said second broadband lens assembly simultaneously, and said long wave lens assembly is operable for focusing light transmitted by said second spectroscope to said FPA imaging unit for imaging;
said second broadband lens assembly is operable for focusing light reflected by said second spectroscope to said Fourier spectrum measuring unit for spectrum acquisition;
said reflector is operable for reflecting light of 0.4˜2 um reflected by said first spectroscope to said third broadband lens assembly, said third spectroscope is operable for transmitting a portion of light of a second predetermined waveband to said visible and near-infrared lens assembly and reflecting the residual portion of light of said second predetermined waveband and light of the residual waveband to said fourth broadband lens assembly simultaneously, and said visible and near-infrared lens assembly is operable for focusing light transmitted by said third spectroscope to said CCD imaging unit for imaging; and
said fourth broadband lens assembly is operable for focusing light reflected by said third spectroscope to said grating spectrum measuring unit for spectrum acquisition.

2. The detecting device of claim 1 , wherein said first predetermined waveband is long wave infrared waveband and said second predetermined waveband is visible and near-infrared waveband.

3. The detecting device of claim 1 , wherein said scanning rotating mirror comprises a plane reflector, a 2D turntable and a servo motor, said plane reflector is fixed on said 2D turntable by a groove therein, two drive shafts of said servo motor are mechanically connected to a pitch axis and a rotation axis of said 2D turntable respectively, and said plane reflector can pitch or rotate with said 2D turntable driven by said servo motor.

4. The detecting device of claim 3 , wherein said plane reflector is gilded K9 glass with a comparatively high reflectivity for visible, near-infrared, short wave infrared, medium wave infrared and long wave infrared light.

5. The detecting device of claim 1 , wherein said Cassegrain mirror assembly uses a Cassegrain system and is formed by a parabolic reflector and a hyperboloid reflector, so as to realize imaging in visible, near-infrared and long wave infrared wavebands and energy gathering of a target.

6. The detecting device of claim 5 , wherein an occlusion ratio between said parabolic reflector and said hyperboloid reflector is no greater than 3:1.

7. The detecting device of claim 1 , wherein said first spectroscope, said second spectroscope and said third spectroscope are plated with a two-layered antireflection film respectively, said first spectroscope reflects visible and near-infrared light totally and transmits short wave, medium wave and long wave infrared light totally, said second spectroscope transmits 50% of long wave infrared light to said long wave lens assembly to realize compensation and calibration of long wave infrared imaging and reflects the residual light to said second broadband lens assembly, and said third spectroscope transmits 50% of visible and near-infrared light to said visible and near-infrared lens assembly to realize compensation and calibration of visible and near-infrared imaging and reflects the residual light to said fourth broadband lens assembly.

8. The detecting device of claim 1 , wherein said first broadband lens assembly and said second broadband lens assembly are operable for compensation and calibration of a converged spot of short wave, medium wave and long wave infrared light, said second broadband lens assembly can be coupled with a short wave, medium wave and long wave infrared fiber for output, said third broadband lens assembly and said fourth broadband lens assembly are operable for compensation and calibration of a converged spot of visible and near-infrared light, and said fourth broadband lens assembly can be coupled with a visible and near-infrared fiber for output.

9. The detecting device of claim 1 , wherein said first broadband lens assembly, said second broadband lens assembly, said third broadband lens assembly and said fourth broadband lens assembly are produced by athermalisation so that locations of imaging surfaces thereof can keep stable at an ambient temperature of −40° C.˜+60° C. without a focusing component.

10. A detecting method based on the detecting device combining images with spectra in an ultra-wide waveband of claim 1 , comprising steps of:
(1) capturing and tracking moving objects and dynamic behaviors by a long wave infrared imaging unit thereby obtaining a long wave infrared image sequence thereof, and capturing and tracking the moving objects and the dynamic behaviors by a visible and near-infrared imaging unit simultaneously thereby obtaining a visible and near-infrared image sequence thereof;
(2) capturing target feature points (x1, y1) of long wave infrared imaging and target feature points (x2, y2) of visible and near-infrared imaging respectively by an object detecting module and outputting coordinates of the target feature points (x1, y1) and coordinates of the target feature points (x2, y2);
(3) outputting target feature points (x, y) of the moving objects and the dynamic behaviors by combining the target feature points (x1, y1) with the target feature points (x2, y2);
(4) moving optical axis of the long wave infrared imaging unit and that of the visible and near-infrared imaging unit respectively to each of the target feature points (x, y) by the scanning rotating mirror;
(5) obtaining ultra-wide waveband infrared spectra by the Fourier spectrum measuring unit and obtaining visible and near-infrared spectra by the grating spectrum measuring unit;
(6) combining images and spectra in visible, near-infrared and long wave infrared wavebands respectively and obtaining images and spectra of the moving objects and the dynamic behaviors in an ultra-wide waveband;
(7) outputting identification of the moving objects and the dynamic behaviors by a recognition module; and
(8) storing the images and the spectra of the moving objects and the dynamic behaviors in the ultra-wide waveband in a target fingerprint database and outputting detection results in real time by a screen.

Assignees

• Univ Huazhong Science Tech

Inventors

• Zhang Tianxu
• Zhang Hong
• Fei Jindong

Classifications

• G01J3/2823 Primary

  Imaging spectrometer · CPC title

• G01J3/0208

  using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction · CPC title

• G01J3/021

  using plane or convex mirrors, parallel phase plates, or particular reflectors · CPC title

• G01B11/002

  for measuring two or more coordinates · CPC title

• G01J3/36

  Investigating two or more bands of a spectrum by separate detectors · CPC title