Big visual field, space compression light beam multi channel imaging optical system
Technical field
The invention belongs to the space optical remote sensor technical field, relate to a kind of visible light/infrared light that is applied to big visual field, space, ultra wide spectrum, multi channel imaging and learn imaging system.
Background technology
Along with the development of remote sensing technology, aspects such as the assessment after resource evaluation, environmental monitoring, disaster alarm and calamity of multispectral imaging remotely-sensed data, city planning, target classification identification have obtained widespread use, have great social benefit and economic benefit.Optical sensor need obtain visible light, near infrared, medium wave and long wave information simultaneously, can also can realize through hyperchannel through single camera through many cameras respectively to each spectral coverage imaging.
Typical multispectral satellite mainly contains the civilian remote sensor of IRS series of Iandsat series, Moderate Imaging Spectroradiomete MODIS, multispectral infrared thermoviewer MTI and the India of the U.S., and domestic multispectral satellite mainly contains CMODIS, resource series, environment is serial, the ocean is serial and the serial satellite of wind and cloud.
The Iandset series satellite optical system of the U.S. and India IRS series satellite optical system spectral coverage are covered as visible/near infrared and short-wave infrared spectral coverage, long wave and long wave spectral coverage spectral information in can't obtaining.The MODIS optical system is realized that by scanning mirror that passes through track scanning and mirror-lens system the spectral coverage scope covers visible light to the LONG WAVE INFRARED spectral coverage, but scanning mirror parts complete machine stability and reliability reduce, can't realize high spectral resolution; The MTI optical system adopts from axle three antistructure patterns, adopt optical filter to cooperate high integration focal plane technology to realize multispectral imaging, but this optical system is difficult to realize big view field imaging, is subject to focal plane integrated technology level, the through engineering approaches difficulty.
Domestic multispectral satellite adopts infrared thermoviewer to realize multispectral imaging with the mode that the visible light camera combines more; Adopt many cameras to realize that obtaining of wide spectrum information will make that the volume and weight of space camera is all very huge; And increased the launch cost of satellite, reduced the fiduciary level of whole star.The domestic CMODIS of having only satellite optical system has adopted single optical system to realize multispectral imaging at present, but its system has determined to realize big visual field from axle two anti-structural shapes.
Summary of the invention
Technology of the present invention is dealt with problems and is: overcome the deficiency of prior art, provide a kind of suitable Space Remote Sensors to carry out the optical system that forms images under big visual field, ultra wide spectrum, the hyperchannel situation.
Technical solution of the present invention is: big visual field, space compression light beam multi channel imaging optical system; Comprise from axle three back-pressures contract light beam do not have burnt telescopic system, second turn back mirror, see light near infrared and infrared spectral coverage color separation film, in involve long wave spectral coverage color separation film, visible and near infrared relay lens group, visible and near infrared focal plane device, the infrared relay lens group of medium wave, medium wave focal plane device, LONG WAVE INFRARED relay lens group, long wave focal plane device, described do not have burnt telescopic system and comprise primary mirror, secondary mirror, first turn back mirror and three mirrors from the axle three back-pressures light beam that contracts; The radiation laser beam of imageable target at first is incident on the primary mirror; Then after secondary mirror, first is turned back mirror and three mirrors, being incident to second successively turns back on the mirror; Second turns back mirror with incident ray turn back back reflection to visible light near infrared and infrared spectral coverage color separation film; Wherein visible light beam and near infrared light beam see through the visible light near infrared and infrared spectral coverage color separation film is incident to visible and near infrared relay lens group, and the emergent ray of visible and near infrared relay lens group is in visible and near infrared focal plane device place imaging; IR involves long wave spectral coverage color separation film in after visible light near infrared and infrared spectral coverage color separation film are turned back once more, being incident to; Involve long wave spectral coverage color separation film during infrared long wave light sees through and be incident to the LONG WAVE INFRARED relay lens group, the emergent ray of LONG WAVE INFRARED relay lens group forms images at long wave focal plane device place; The medium wave IR through in involve and be incident to the infrared relay lens group of medium wave after long wave spectral coverage color separation film is turned back once more, the emergent ray of the infrared relay lens group of medium wave forms images at medium wave focal plane device place.
Described visible and near infrared relay lens group comprises the first gummed negative lens, the first biconvex positive lens, the second gummed negative lens, the second biconvex positive lens, the first curved moon negative lens that sets gradually through order according to light.
The described first gummed negative lens, the first biconvex positive lens, the second gummed negative lens, the second biconvex positive lens and first a curved moon negative lens are colouless optical glass, and lens face shape is sphere.
The infrared relay lens group of described medium wave comprises the first curved moon positive lens, the first curved moon negative lens, the second curved moon positive lens, the second curved moon negative lens, the 3rd curved moon positive lens, the 3rd curved moon negative lens that sets gradually through order according to light.
The described first curved moon positive lens, the first curved moon negative lens, the second curved moon positive lens, the second curved moon negative lens, the 3rd curved moon positive lens and the 3rd a curved moon negative lens are colourless glasses for infrared use; The face shape of three curved month negative lenses is an aspheric surface, and the face shape of three curved month positive lenss is a sphere.
Described LONG WAVE INFRARED relay lens group comprises the first curved moon positive lens, the second curved moon positive lens, the first curved moon negative lens, the 3rd curved moon positive lens, the second curved moon negative lens that sets gradually through order according to light.
The described first curved moon positive lens, the second curved moon positive lens, the first curved moon negative lens, the 3rd curved moon positive lens and second a curved moon negative lens are colourless glasses for infrared use; The face shape of the second curved moon positive lens, the 3rd curved moon positive lens and the second curved moon negative lens is aspheric surface, and the face shape of the first curved moon positive lens and the first curved moon negative lens is sphere.
Focal distance f=M * the f3 of big visual field, described space compression light beam multi channel imaging optical system; The focal length of near infrared relay lens group, the infrared relay lens group of medium wave and LONG WAVE INFRARED relay lens group is f3; M=f1/f2; F1 is preceding group of objective focal length of the burnt telescopic system of nothing that is made up of primary mirror and secondary mirror, and f2 is the focal length of back group of object lens of nothing Jiao telescopic system of being made up of three mirrors.
The face shape of described primary mirror and three mirrors is recessed non-spherical reflector, and the face shape of secondary mirror is protruding spherical reflector or non-spherical reflector.
The material of described primary mirror, secondary mirror, three mirrors is a silit, devitrified glass, or fused quartz.
The present invention's advantage compared with prior art is:
1) primary optical system of the present invention has effectively reduced the quantity of primary optical system optical element, no color differnece owing to adopted from the axle three back-pressures light beam that contracts and do not have the pattern that Jiao looks in the distance; Nothing is blocked; Volume is little, adopts dull and stereotyped color separation film to realize beam split behind the parallel light emergence, and the positional precision of color separation film can not introduced aberration; Can to visible/near infrared passage and two infrared channels be debug respectively, picture element detects, reduced the complexity that system is debug;
2) the present invention from the emergent pupil bore of axle three reflecting optical systems compression parallel light path be optical system entrance pupil diameter
doubly; Thereby
first color separation film that the bore of follow-up optical system is reduced to the entrance pupil diameter is placed near the emergent pupil, has effectively reduced the bore of the size and the subsequent optical system of color separation film;
3) optical system of the present invention adopts parallel light path to add the pattern realization multi channel imaging of dull and stereotyped inclination color separation film; Can't introduce aberration owing to add the inclination optical element in the parallel light path, can expand the imaging passage through the method that in parallel light path, increases color separation film;
4) optical system of the present invention have the mechanical-optical setup compactness, form simple, in ultra wide spectrum scope image quality well, be easy to advantage such as realization; Can use the imaging that realizes big visual field than short-term array detector array; For airborne/spaceborne high-resolution multi-spectral imaging system has proposed a technological preferably realization approach, be specially adapted to continue, stably obtain the detected with high accuracy satellite optical system of face of land information.
Description of drawings
Fig. 1 forms structural representation for optical system of the present invention;
Fig. 2 is visible and near infrared relay lens group structural representation for the present invention;
Fig. 3 is a shortwave relay lens group structural representation of the present invention;
Fig. 4 is a long wave relay lens group structural representation of the present invention.
Embodiment
As shown in Figure 1, optical system of the present invention does not have the turn back infrared relay lens group of mirror 5, visible light near infrared/infrared spectral coverage color separation film 6, medium wave/long wave spectral coverage color separation film 7, visible light and near infrared relay lens group 8, visible light and near infrared focal plane device 9, medium wave 10, medium wave focal plane device 11, LONG WAVE INFRARED relay lens group 12, long wave focal plane device 13 of burnt telescopic system (being made up of turn back mirror 3 and three mirrors 4 of primary mirror 1, secondary mirror 2, first), second by the light beam that contracts from axle three back-pressures and forms.Preceding group of object lens (primary mirror 1 and the secondary mirror 2) focal length that does not have burnt telescopic system is f1, and the focal length of back group object lens (three mirrors 4) is f2, and the focal length of three relay lens group is f3; The light beam ratio of compression that does not then have burnt telescopic system is M=f1/f2, the focal distance f=M * f3 of whole compression light beam multi channel imaging system.
The work spectral coverage of optical system of the present invention is 0.45 μ m-12 μ m, is subdivided into three passages, 3 spectral coverages.The spectral coverage scope that visible light and near infrared passage are corresponding is: 0.45 μ m-0.90 μ m, and the spectral coverage that the medium wave passage is corresponding is: 3 μ m-5 μ m; The spectral coverage scope that the long wave passage is corresponding is: 8 μ m-12 μ m.
0.45 μ m-0.90 μ m spectral coverage constitutes visible light and near infrared passage, visible light and near infrared passage diaphragm are arranged on secondary mirror 2 positions.The light of visible light and near infrared light path does not have burnt telescopic system compression parallel beam through the light beam that contracts from axle three back-pressures, behind visible near-infrared/infrared spectral coverage color separation film 6, sees through visible light and near infrared relay lens group 8 to visible light and 9 imagings of near infrared focal plane device; Wherein visible light focal plane device 9 is face battle array or linear array device.Visible near-infrared/infrared spectral coverage color separation film 6 is positioned near the emergent pupil of axle three anti-no burnt telescopic systems, realizes that the color separation film bore minimizes, and size is about D/M, and D is the entrance pupil bore from axle three anti-no burnt telescopic systems.
3.50 μ m-5.0 μ m spectral coverage constitutes the medium wave infrared channel, medium wave infrared channel diaphragm is arranged on its entrance pupil position.The light of the infrared light path of medium wave is through behind axle three anti-no burnt telescopic system compression parallel beams; Be transmitted through medium wave/long wave spectral coverage color separation film 7 through visible light near infrared/infrared spectral coverage color separation film 6; Reflex to the infrared relay lens group 10 of medium wave by medium wave/long wave spectral coverage color separation film 7 then, converge to image formation by rays to the medium short wave focal plane device 11 of the medium wave light path behind the emergent pupil.
8.0 μ m-12.0 μ m constitutes the LONG WAVE INFRARED passage, LONG WAVE INFRARED passage diaphragm is arranged on its entrance pupil position.The light of LONG WAVE INFRARED light path is through compressing parallel beams after visible light near infrared/infrared spectral coverage color separation film 6 is transmitted through medium wave/long wave spectral coverage color separation film 7 from axle three anti-no burnt telescopic systems; Be transmitted through LONG WAVE INFRARED relay lens group 12 by medium wave/long wave spectral coverage color separation film 7 then, the light that converges to the LONG WAVE INFRARED light path behind the emergent pupil forms images to long wave focal plane device 13 at last.
The focal length of three optical channels of optical system of the present invention is inconsistent, visible/near infrared passage relative aperture is 1/4, and the infrared relative aperture of medium wave is 1/3.5, and the LONG WAVE INFRARED relative aperture is 1/3.Entrance pupil is positioned at primary mirror 1 the place ahead, the shared entrance pupil of triple channel.Three passage visual field sizes are 4.5 ° (vertically dividing line direction) * 0.5 ° (along heading).
Coaxial from axle three anti-no burnt telescopic system physics; The central shaft that is primary mirror 1, secondary mirror 2, three mirrors 4 overlaps; Center with secondary mirror 2 is a central shaft, and each catoptron all uses local bore, is zero from visual field, the center chief ray of axle three anti-no burnt telescope optical systems and the angle of image planes normal.Primary mirror 1 and three mirrors 4 all adopt recessed catoptron, and secondary mirror 2 is a convex mirror, for guaranteeing the image quality of visible channel, increase the system design degree of freedom, and primary mirror 1, secondary mirror 2 and three mirrors 4 all can adopt aspheric mirror.Primary mirror 1 is the secondary hyperboloid, and secondary mirror 2 is sphere or ellipse aspheric surface, and three mirrors 4 are the secondary ellipsoid.The material that primary mirror 1, secondary mirror 2, three mirrors 4 adopt is a metallic beryllium, or crystallite, or silit, or melts quartz.
The reflecting surface of primary mirror 1, secondary mirror 2, three mirrors 4 is aluminized or the metal high reflectance reflectance coating of ag material; The surface plating anti-reflection film that all lens contact with air in the infrared relay lens group 10 of medium wave and the LONG WAVE INFRARED relay lens group 12 is used to increase the energy efficiency of imaging optical system.
Visible light near infrared/infrared spectral coverage color separation film 6 is dull and stereotyped, and whole color separation film tilts to place, and the plane of light incidence pitch angle is positioned at from axle three anti-no burnt telescopic system emergent pupil places for to be rotated counterclockwise 45 ° along optical axis, realizes the color separation of visible light near infrared/infrared spectral coverage.
Medium wave/long wave spectral coverage color separation film 7 is dull and stereotyped, is arranged in from axle three anti-no burnt telescopic system compression parallel beams, and medium wave/long wave spectral coverage color separation film 7 tilts to place, and light incidence surface normal and optical axis included angle are for turning clockwise 45 °.
Visible light near infrared/infrared spectral coverage color separation film 6 and medium wave/long wave spectral coverage color separation film 7 all adopts the zinc selenide material, and two surfaces are the plane.Visible near-infrared/infrared, the medium wave/long wave spectral coverage dichroic coating of plating is realized visible light near infrared/infrared spectral coverage and medium wave/long wave spectral coverage color separation on plane of light incidence.
First color separation film (6) and follow-up all optical elements with from the axle three anti-no burnt telescopic system disalignments; First color separation film (6) central shaft and secondary mirror 4 central shafts are 35mm at vertical axial offset distance, and are consistent with light bore in the visual field that guarantees subsequent optical system bore and a use partially.
First the turn back surface shape of mirror 5 of mirror 3 and second of turning back is the plane, tilts to place, and adopts micro crystal material, or aluminium base silit.Light incidence surface normal and optical axis included angle are for turning clockwise 45 °.
Visible light and near infrared relay lens group 8 are as shown in Figure 2, and lens combination comprises five lens, are made up of gummed negative lens, biconvex positive lens, gummed negative lens, biconvex positive lens, a curved month negative lens, and lens face shape is sphere, the lens combination optical axis coincidence.
It is thus clear that and near infrared focal plane device 9 is TDICCD linear array or face battle array device.
The infrared relay lens group of medium wave 10 is made up of six-element lens, all adopts colourless glasses for infrared use, and is as shown in Figure 3.Comprise the first curved moon positive lens, the first curved moon negative lens, the second curved moon positive lens, the second curved moon negative lens, the 3rd curved moon positive lens, the 3rd curved moon negative lens.Lens material is respectively: the first curved moon positive lens, the second curved moon positive lens and the second curved moon negative lens are germanium, and the first curved moon negative lens and the 3rd curved moon positive lens are silicon, and the 3rd curved moon negative lens is a zinc sulphide.Wherein, the face shape of three curved month negative lenses is an aspheric surface, and the aspheric surface type is respectively the secondary hyperboloid, or six ellipsoids, or eight ellipsoids, and all the other lens face shapes are sphere.The six-element lens optical axis coincidence, common spherical aberration corrector, coma and aberration, and medium wave passage emergent pupil drawn.
LONG WAVE INFRARED relay lens group 12 is made up of five lens, all adopts colourless glasses for infrared use, and is as shown in Figure 4.Lens combination comprises the first curved moon positive lens, the second curved moon positive lens, the first curved moon negative lens, the 3rd curved moon positive lens, the second curved moon negative lens.Lens material is respectively: the first curved moon positive lens, the second curved moon negative lens are germanium, and the first curved moon negative lens and the second curved moon positive lens are zinc selenide, and the 3rd curved moon negative lens is a zinc sulphide.Wherein, the face shape of the second curved moon positive lens, the 3rd curved moon positive lens and the second curved moon negative lens is aspheric surface, and all the other lens face shapes are sphere.Five lens axis overlap, common spherical aberration corrector, coma and aberration, and long-pass road emergent pupil drawn.
Medium wave focal plane device 11 is rectangular surfaces array detector or linear array detector spare with long wave focal plane device 13.
The content of not doing to describe in detail in the instructions of the present invention belongs to those skilled in the art's known technology.