Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution...Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution and wide FOV,infrared optical systems often adopt complex optical lens groups,which will increase the size and weight of the optical system.In this paper,a strategy based on wavefront coding(WFC)is proposed to design a compact wide-FOV infrared imager.A cubic phase mask is inserted into the pupil plane of the infrared imager to correct the aberration.The simulated results show that,the WFC infrared imager has good imaging quality in a wide FOV of±16°.In addition,the WFC infrared imager achieves compactness with its 40 mm×40 mm×40 mm size.A fast focal ratio of 1 combined with an entrance pupil diameter of 25 mm ensures brightness.This work is of significance for designing a compact wide-FOV infrared imager.展开更多
We report a new standalone Robotic All-Sky narrowband Imager(RASI)for auroral and airglow studies.RASI has new optics and an electromechanical system,low operation and installation costs,easy deployment and fully auto...We report a new standalone Robotic All-Sky narrowband Imager(RASI)for auroral and airglow studies.RASI has new optics and an electromechanical system,low operation and installation costs,easy deployment and fully automatic features.The new optics provide an all-sky field of view with excellent image quality and sensitivity.The new electromechanical system design offers a more compact size and the capability for outdoor independent deployment.We have also developed a fully automatic data acquisition software for RASI,which is based on the perception of solar altitude and the all-sky cloud cover.In conclusion,the RASI demonstrates significant advantages over the traditional all-sky narrowband imager,and it is highly suitable for the intensity measurements of large-scale auroras and airglow distributions.展开更多
Experimental research into the boiling-up of a free jet of superheated water discharging through a short cylindrical nozzle with sharp inlet and outlet edges into the atmosphere has been carried out.The change in the ...Experimental research into the boiling-up of a free jet of superheated water discharging through a short cylindrical nozzle with sharp inlet and outlet edges into the atmosphere has been carried out.The change in the shape of a liquid jet has been traced through changes in thermodynamic parameters(temperature,pressure)along the saturation line in both the visible range and the infrared spectrum.The flow shapes corresponding to various modes of boiling-up have been identified.With thermal-imaging diagnostics,heterogeneities in the spray plume of a superheated liquid jet have been recorded and temperature distributions have been obtained in various sections of a boiling-up flow.The maximum temperature in the flare of a boiling-up jet has been determined at different distances from the short nozzle’s exit edge.展开更多
Multispectral imaging,which simultaneously captures the spatial and spectral information of a scene,is widely used across diverse fields,including remote sensing,biomedical imaging,and agricultural monitoring.We intro...Multispectral imaging,which simultaneously captures the spatial and spectral information of a scene,is widely used across diverse fields,including remote sensing,biomedical imaging,and agricultural monitoring.We introduce a snapshot multispectral imaging approach employing a standard monochrome image sensor with no additional spectral filters or customized components.Our system leverages the inherent chromatic aberration of wavelength-dependent defocusing as a natural source of physical encoding of multispectral information;this encoded image information is rapidly decoded via a deep learning-based multispectral Fourier imager network(mFIN).We experimentally tested our method with six illumination bands and demonstrated an overall accuracy of 98.25%for predicting the illumination channels at the input and achieved a robust multispectral image reconstruction on various test objects.This deep learning-powered framework achieves high-quality multispectral image reconstruction using snapshot image acquisition with a monochrome image sensor and could be useful for applications in biomedicine,industrial quality control,and agriculture,among others.展开更多
Airborne hyperspectral imaging spectrometers have been used for Earth observation over the past four decades.Despite the high sensitivity of push-broom hyperspectral imagers,they experience limited swath and wavelengt...Airborne hyperspectral imaging spectrometers have been used for Earth observation over the past four decades.Despite the high sensitivity of push-broom hyperspectral imagers,they experience limited swath and wavelength coverage.In this study,we report the development of a push-broom airborne multimodular imaging spectrometer(AMMIS)that spans ultraviolet(UV),visible near-infrared(VNIR),shortwave infrared(SWIR),and thermal infrared(TIR)wavelengths.As an integral part of China's HighResolution Earth Observation Program,AMMIS is intended for civilian applications and for validating key technologies for future spaceborne hyperspectral payloads.It has been mounted on aircraft platforms such as Y-5,Y-12,and XZ-60.Since 2016,AMMIS has been used to perform more than 30 flight campaigns and gather more than 200 TB of hyperspectral data.This study describes the system design,calibration techniques,performance tests,flight campaigns,and applications of the AMMIS.The system integrates UV,VNIR,SWIR,and TIR modules,which can be operated in combination or individually based on the application requirements.Each module includes three spectrometers,utilizing field-of-view(FOV)stitching technology to achieve a 40°FOV,thereby enhancing operational efficiency.We designed advanced optical systems for all modules,particularly for the TIR module,and employed cryogenic optical technology to maintain optical system stability at 100 K.Both laboratory and in-flight calibrations were conducted to improve preprocessing accuracy and produce high-quality hyperspectral data.The AMMIS features more than 1400 spectral bands,with spectral sampling intervals of 0.1 nm for UV,2.4 nm for VNIR,3 nm for SWIR,and 32 nm for TIR.In addition,the instantaneous fields of view(IFoVs)for the four modules were 0.5,0.25,0.5,and 1 mrad,respectively,with the VNIR module achieving an IFoV of 0.125 mrad in the high-spatial-resolution mode.This study reports on land-cover surveys,pollution gas detection,mineral exploration,coastal water detection,and plant investigations conducted using AMMIS,highlighting its excellent performance.Furthermore,we present three hyperspectral datasets with diverse scene distributions and categories suitable for developing artificial intelligence algorithms.This study paves the way for next-generation airborne and spaceborne hyperspectral payloads and serves as a valuable reference for hyperspectral sensor designers and data users.展开更多
AIM:To evaluate parameters measured using the tear film imager(TFI)prototype,a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers.METHODS:In this cross-sectional study,pati...AIM:To evaluate parameters measured using the tear film imager(TFI)prototype,a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers.METHODS:In this cross-sectional study,patients with dry eye,meibomian gland dysfunction(MGD),and non-dry eye/MGD from February 2020 to January 2021 were analyzed.Quantified TFI outputs included lipid layer thickness(LLT),mucoaqueous layer thickness(MALT),MALT rate of change(MALTR),and lipid breakup time.Two other interferometry devices,LipiView2 and DR-1α,were used for comparison.TFI outputs and other clinical parameters were analyzed using correlation coefficients.Each patient underwent one or several study visits.Baseline values of three device outputs,other clinical parameters,and their changes were examined.RESULTS:This study involved 28 patients(8 patients with dry eyes,13 with MGD,and 7 with non-dry eye/MGD).Baseline TFI,LipiView2,and DR-1αvalues were associated with various clinical parameters.The LLT values estimated using TFI had a correlation with the plugging score in the upper eyelid(r=−0.42).Several TFI values have correlated better than LipiView2 and DR-1α,particularly with questionnaire scores.MALTR by TFI revealed a correlation between standardized patient evaluation on eye dryness(SPEED)and dry eye-related quality of life score(DEQS)scores(r=0.59,0.43),respectively.CONCLUSION:TFI enabled to quantify the LLT and MALT separately over time and shows the moderate correlations between TFI measurements and clinical parameters,which yields the potential for TFI to serve as a complementary tool for assessing dry eye and MGD.展开更多
As an emerging microscopic detection tool,quantum microscopes based on the principle of quantum precision measurement have attracted widespread attention in recent years.Compared with the imaging of classical light,qu...As an emerging microscopic detection tool,quantum microscopes based on the principle of quantum precision measurement have attracted widespread attention in recent years.Compared with the imaging of classical light,quantum-enhanced imaging can achieve ultra-high resolution,ultra-sensitive detection,and anti-interference imaging.Here,we introduce a quantum-enhanced scanning microscope under illumination of an entangled NOON state in polarization.For the phase imager with NOON states,we propose a simple four-basis projection method to replace the four-step phase-shifting method.We have achieved the phase imaging of micrometer-sized birefringent samples and biological cell specimens,with sensitivity close to the Heisenberg limit.The visibility of transmittance-based imaging shows a great enhancement for NOON states.Besides,we also demonstrate that the scanning imaging with NOON states enables the spatial resolution enhancement of√N compared with classical measurement.Our imaging method may provide some reference for the practical application of quantum imaging and is expected to promote the development of microscopic detection.展开更多
Awell-anticipated wide-field X-ray focusing imager,the Einstein Probe(EP,also named“Tianguan”in Chinese)has caught the eye of astronomers since its launch in January 2024.Initiated and sponsored by the Chinese Acade...Awell-anticipated wide-field X-ray focusing imager,the Einstein Probe(EP,also named“Tianguan”in Chinese)has caught the eye of astronomers since its launch in January 2024.Initiated and sponsored by the Chinese Academy of Sciences(CAS),and developed in cooperation with the European Space Agency(ESA).展开更多
Numerous coal fires burn underneath the Datong coalfield because of indiscriminate mining.Landsat TM/ETM,unmanned aerial vehicle（UAV）,and infrared thermal imager were employed to monitor underground coal fires in th...Numerous coal fires burn underneath the Datong coalfield because of indiscriminate mining.Landsat TM/ETM,unmanned aerial vehicle（UAV）,and infrared thermal imager were employed to monitor underground coal fires in the Majiliang mining area.The thermal field distributions of this area in 2000,2002,2006,2007,and 2009 were obtained using Landsat TM/ETM.The changes in the distribution were then analyzed to approximate the locations of the coal fires.Through UAV imagery employed at a very high resolution（0.2 m）,the texture information,linear features,and brightness of the ground fissures in the coal fire area were determined.All these data were combined to build a knowledge model of determining fissures and were used to support underground coal fire detection.An infrared thermal imager was used to map the thermal field distribution of areas where coal fire is serious.Results were analyzed to identify the hot spot trend and the depth of the burning point.展开更多
To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in Septemb...To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in September of 2000 at Daxing'anling district of Heilongjiang Province, China. The ratio analysis of reflectance spectra (RARS) indices, which were put forward by Chappelle et al (1992), are chosen in this paper owing to their effect and simpleness against both comparison with various methods and techniques for exploration of pigment concentration and characteristics of PHI data. The correlation coefficients between RARS indices and pigment concentration of vegetation were up to 0.8. The new RARS indices modes are established in the two test areas using both PHI data and spectra of different vegetations measured in the field. The indices' parameter images of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Cars) of the test areas covered with swamp and flourish vegetation are acquired by the new RARS indices modes. Furthermore, the regional concentration of Chl a and Chl b are extracted and quantified using regression equations between RARS indices and pigment concentrations, which were built by Blackburn (1998). The results showed the physiological status and variety clearly, and are in good agreement with the distribution of vegetation in the field.展开更多
文摘Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution and wide FOV,infrared optical systems often adopt complex optical lens groups,which will increase the size and weight of the optical system.In this paper,a strategy based on wavefront coding(WFC)is proposed to design a compact wide-FOV infrared imager.A cubic phase mask is inserted into the pupil plane of the infrared imager to correct the aberration.The simulated results show that,the WFC infrared imager has good imaging quality in a wide FOV of±16°.In addition,the WFC infrared imager achieves compactness with its 40 mm×40 mm×40 mm size.A fast focal ratio of 1 combined with an entrance pupil diameter of 25 mm ensures brightness.This work is of significance for designing a compact wide-FOV infrared imager.
基金the projects of the CAS“Light of West China”Program,the National Natural Science Foundation of China(11573067)the Science and Technology Program of Shanghai(21DZ206100)+2 种基金the Ground-based Space Environment Monitoring Network(Chinese Meridian Project II)the Yunnan Revitalization Talent Support Program-Science&Technology Champion Project(202105AB160001)the Chinese National Antarctic&Arctic Research Expedition for the support of the all-sky auroral/airglow imager program at the Longyearbyen Station and Lijiang Station.
文摘We report a new standalone Robotic All-Sky narrowband Imager(RASI)for auroral and airglow studies.RASI has new optics and an electromechanical system,low operation and installation costs,easy deployment and fully automatic features.The new optics provide an all-sky field of view with excellent image quality and sensitivity.The new electromechanical system design offers a more compact size and the capability for outdoor independent deployment.We have also developed a fully automatic data acquisition software for RASI,which is based on the perception of solar altitude and the all-sky cloud cover.In conclusion,the RASI demonstrates significant advantages over the traditional all-sky narrowband imager,and it is highly suitable for the intensity measurements of large-scale auroras and airglow distributions.
文摘Experimental research into the boiling-up of a free jet of superheated water discharging through a short cylindrical nozzle with sharp inlet and outlet edges into the atmosphere has been carried out.The change in the shape of a liquid jet has been traced through changes in thermodynamic parameters(temperature,pressure)along the saturation line in both the visible range and the infrared spectrum.The flow shapes corresponding to various modes of boiling-up have been identified.With thermal-imaging diagnostics,heterogeneities in the spray plume of a superheated liquid jet have been recorded and temperature distributions have been obtained in various sections of a boiling-up flow.The maximum temperature in the flare of a boiling-up jet has been determined at different distances from the short nozzle’s exit edge.
文摘Multispectral imaging,which simultaneously captures the spatial and spectral information of a scene,is widely used across diverse fields,including remote sensing,biomedical imaging,and agricultural monitoring.We introduce a snapshot multispectral imaging approach employing a standard monochrome image sensor with no additional spectral filters or customized components.Our system leverages the inherent chromatic aberration of wavelength-dependent defocusing as a natural source of physical encoding of multispectral information;this encoded image information is rapidly decoded via a deep learning-based multispectral Fourier imager network(mFIN).We experimentally tested our method with six illumination bands and demonstrated an overall accuracy of 98.25%for predicting the illumination channels at the input and achieved a robust multispectral image reconstruction on various test objects.This deep learning-powered framework achieves high-quality multispectral image reconstruction using snapshot image acquisition with a monochrome image sensor and could be useful for applications in biomedicine,industrial quality control,and agriculture,among others.
基金supported by the Shanghai Industrial Collaborative Innovation Fund(HCXBCY-2021-001)the Academy of Finland(349229)。
文摘Airborne hyperspectral imaging spectrometers have been used for Earth observation over the past four decades.Despite the high sensitivity of push-broom hyperspectral imagers,they experience limited swath and wavelength coverage.In this study,we report the development of a push-broom airborne multimodular imaging spectrometer(AMMIS)that spans ultraviolet(UV),visible near-infrared(VNIR),shortwave infrared(SWIR),and thermal infrared(TIR)wavelengths.As an integral part of China's HighResolution Earth Observation Program,AMMIS is intended for civilian applications and for validating key technologies for future spaceborne hyperspectral payloads.It has been mounted on aircraft platforms such as Y-5,Y-12,and XZ-60.Since 2016,AMMIS has been used to perform more than 30 flight campaigns and gather more than 200 TB of hyperspectral data.This study describes the system design,calibration techniques,performance tests,flight campaigns,and applications of the AMMIS.The system integrates UV,VNIR,SWIR,and TIR modules,which can be operated in combination or individually based on the application requirements.Each module includes three spectrometers,utilizing field-of-view(FOV)stitching technology to achieve a 40°FOV,thereby enhancing operational efficiency.We designed advanced optical systems for all modules,particularly for the TIR module,and employed cryogenic optical technology to maintain optical system stability at 100 K.Both laboratory and in-flight calibrations were conducted to improve preprocessing accuracy and produce high-quality hyperspectral data.The AMMIS features more than 1400 spectral bands,with spectral sampling intervals of 0.1 nm for UV,2.4 nm for VNIR,3 nm for SWIR,and 32 nm for TIR.In addition,the instantaneous fields of view(IFoVs)for the four modules were 0.5,0.25,0.5,and 1 mrad,respectively,with the VNIR module achieving an IFoV of 0.125 mrad in the high-spatial-resolution mode.This study reports on land-cover surveys,pollution gas detection,mineral exploration,coastal water detection,and plant investigations conducted using AMMIS,highlighting its excellent performance.Furthermore,we present three hyperspectral datasets with diverse scene distributions and categories suitable for developing artificial intelligence algorithms.This study paves the way for next-generation airborne and spaceborne hyperspectral payloads and serves as a valuable reference for hyperspectral sensor designers and data users.
基金Supported by Topcon Corporation and Santen Pharmaceutical Co.Ltd.
文摘AIM:To evaluate parameters measured using the tear film imager(TFI)prototype,a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers.METHODS:In this cross-sectional study,patients with dry eye,meibomian gland dysfunction(MGD),and non-dry eye/MGD from February 2020 to January 2021 were analyzed.Quantified TFI outputs included lipid layer thickness(LLT),mucoaqueous layer thickness(MALT),MALT rate of change(MALTR),and lipid breakup time.Two other interferometry devices,LipiView2 and DR-1α,were used for comparison.TFI outputs and other clinical parameters were analyzed using correlation coefficients.Each patient underwent one or several study visits.Baseline values of three device outputs,other clinical parameters,and their changes were examined.RESULTS:This study involved 28 patients(8 patients with dry eyes,13 with MGD,and 7 with non-dry eye/MGD).Baseline TFI,LipiView2,and DR-1αvalues were associated with various clinical parameters.The LLT values estimated using TFI had a correlation with the plugging score in the upper eyelid(r=−0.42).Several TFI values have correlated better than LipiView2 and DR-1α,particularly with questionnaire scores.MALTR by TFI revealed a correlation between standardized patient evaluation on eye dryness(SPEED)and dry eye-related quality of life score(DEQS)scores(r=0.59,0.43),respectively.CONCLUSION:TFI enabled to quantify the LLT and MALT separately over time and shows the moderate correlations between TFI measurements and clinical parameters,which yields the potential for TFI to serve as a complementary tool for assessing dry eye and MGD.
基金supported by he National Natural Science Foundation of China(Grant Nos.12304359,12304398,12404382,12234009,12274215,and 12427808)the China Postdoctoral Science Foundation(Grant No.2023M731611)+4 种基金the Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2023ZB717)Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301400)Key R&D Program of Jiangsu Province(Grant No.BE2023002)Natural Science Foundation of Jiangsu Province(Grant Nos.BK20220759 and BK20233001)Program for Innovative Talents and Entrepreneurs in Jiangsu,and Key R&D Program of Guangdong Province(Grant No.2020B0303010001).
文摘As an emerging microscopic detection tool,quantum microscopes based on the principle of quantum precision measurement have attracted widespread attention in recent years.Compared with the imaging of classical light,quantum-enhanced imaging can achieve ultra-high resolution,ultra-sensitive detection,and anti-interference imaging.Here,we introduce a quantum-enhanced scanning microscope under illumination of an entangled NOON state in polarization.For the phase imager with NOON states,we propose a simple four-basis projection method to replace the four-step phase-shifting method.We have achieved the phase imaging of micrometer-sized birefringent samples and biological cell specimens,with sensitivity close to the Heisenberg limit.The visibility of transmittance-based imaging shows a great enhancement for NOON states.Besides,we also demonstrate that the scanning imaging with NOON states enables the spatial resolution enhancement of√N compared with classical measurement.Our imaging method may provide some reference for the practical application of quantum imaging and is expected to promote the development of microscopic detection.
文摘Awell-anticipated wide-field X-ray focusing imager,the Einstein Probe(EP,also named“Tianguan”in Chinese)has caught the eye of astronomers since its launch in January 2024.Initiated and sponsored by the Chinese Academy of Sciences(CAS),and developed in cooperation with the European Space Agency(ESA).
基金Project(201412016)supported by the Special Fund for Public Projects of National Administration of Surveying,Mapping and Geoinformation of ChinaProject(51174287)supported by the National Natural Science Foundation of China
文摘Numerous coal fires burn underneath the Datong coalfield because of indiscriminate mining.Landsat TM/ETM,unmanned aerial vehicle（UAV）,and infrared thermal imager were employed to monitor underground coal fires in the Majiliang mining area.The thermal field distributions of this area in 2000,2002,2006,2007,and 2009 were obtained using Landsat TM/ETM.The changes in the distribution were then analyzed to approximate the locations of the coal fires.Through UAV imagery employed at a very high resolution（0.2 m）,the texture information,linear features,and brightness of the ground fissures in the coal fire area were determined.All these data were combined to build a knowledge model of determining fissures and were used to support underground coal fire detection.An infrared thermal imager was used to map the thermal field distribution of areas where coal fire is serious.Results were analyzed to identify the hot spot trend and the depth of the burning point.
文摘To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in September of 2000 at Daxing'anling district of Heilongjiang Province, China. The ratio analysis of reflectance spectra (RARS) indices, which were put forward by Chappelle et al (1992), are chosen in this paper owing to their effect and simpleness against both comparison with various methods and techniques for exploration of pigment concentration and characteristics of PHI data. The correlation coefficients between RARS indices and pigment concentration of vegetation were up to 0.8. The new RARS indices modes are established in the two test areas using both PHI data and spectra of different vegetations measured in the field. The indices' parameter images of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Cars) of the test areas covered with swamp and flourish vegetation are acquired by the new RARS indices modes. Furthermore, the regional concentration of Chl a and Chl b are extracted and quantified using regression equations between RARS indices and pigment concentrations, which were built by Blackburn (1998). The results showed the physiological status and variety clearly, and are in good agreement with the distribution of vegetation in the field.
