[Show abstract][Hide abstract]ABSTRACT: This paper reviews progress in hyperspectral remote sensing (HRS) in China, focusing on the past three decades. China has made great achievements since starting in this promising field in the early 1980s. A series of advanced hyperspectral imaging systems ranging from ground to airborne and satellite platforms have been designed, built, and operated. These include the field imaging spectrometer system (FISS), the Modular Airborne Imaging Spectrometer (MAIS), and the Chang'E-I Interferometer Spectrometer (IIM). In addition to developing sensors, Chinese scientists have proposed various novel image processing techniques. Applications of hyperspectral imaging in China have been also performed including mineral exploration in the Qilian Mountains and oil exploration in Xinjiang province. To promote the development of HRS, many generic and professional software tools have been developed. These tools such as the Hyperspectral Image Processing and Analysis System (HIPAS) incorporate a number of special algorithms and features designed to take advantage of the wealth of information contained in HRS data, allowing them to meet the demands of both common users and researchers in the scientific community.
Full-text · Article · Jan 2014 · IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
[Show abstract][Hide abstract]ABSTRACT: Because sample are affected by light, lens and sensor in optical channel in hyperspectral imaging system, image quality and spectrums are also affected. The paper proposes the gray correction coefficient algorithm with spatial dimension and spectral dimension to preprocess molecular hyperspectral imaging data. The experimental results show that the algorithm can carry out radiometric correction in spatial dimension and spectral dimension and eliminate the effects of light, lens and sensor. Image quality is significantly improved. The spectrum curves indicating true biochemical characteristics of the sample are extracted that classification results based on spectral information are better than uncorrected sample. Keywords-molecular hyperspctral imaging(MHSI), radiometric correction, spectral angle mapper
[Show abstract][Hide abstract]ABSTRACT: A Field Imaging Spectrometer System (FISS) based on a cooling area CCD was developed. This paper describes the principle, structural design, main technology parameters and data processing flow, as well as some application experiments using the FISS instrument. The FISS instrument shows huge potential applications in geology, food, agriculture, forestry and other respective field.
[Show abstract][Hide abstract]ABSTRACT: A novel molecular hyperspectral imaging (MHSI) system based on AOTF (acousto-optic tunable filters) was presented. AOTF is a rapid wavelength-scanning solid-state device that operates as a tunable optical band pass filter. AOTF offers the advantage of having no moving parts and can be scanned at very high rates. The system consists of microscope, AOTF-based spectrometer, matrix CCD, image collection card and computer. The spectral range of the MHSI is from 550 to 1000 nm. The spectral resolution is less than 2 nm, and the spatial resolution is about 0.3 μm. The valid pixels are 1024×1024. The system can capture 30 frames per min in burst mode of CCD. The system not only can supply single band images in the visible range, but also spectrum curve of random pixel of sample image. Each pixel of the image has two properties: the spectral property and the luminance property. Initial experiment shows that molecular hyperspectral imaging system coupled with multivariate data analysis is a powerful new tool for understanding complex biological and biomedical samples.
[Show abstract][Hide abstract]ABSTRACT: Several composite camera systems were made for wide coverage by using 3 or 4 oblique cameras. A virtual projecting center and image was used for geometrical correction and mosaic with different projecting angles and different spatial resolutions caused by oblique cameras. An imaging method based axis-shift theory is proposed to acquire wide coverage images by several upright cameras. Four upright camera lenses have the same wide angle of view. The optic axis of lens is not on the center of CCD, and each CCD in each camera covers only one part of the whole focus plane. Oblique deformation caused by oblique camera would be avoided by this axis-shift imaging method. The principle and parameters are given and discussed. A prototype camera system is constructed by common DLSR (digital single lens reflex) cameras. The angle of view could exceed 80 degrees along the flight direction when the focal length is 24mm, and the ratio of base line to height could exceed 0.7 when longitudinal overlap is 60%. Some original and mosaic images captured by this prototype system in some ground and airborne experiments are given at last. Experimental results of image test show that the upright imaging method can effectively avoid the oblique deformation and meet the geometrical precision of image mosaic.
No preview · Article · Nov 2010 · Proceedings of SPIE - The International Society for Optical Engineering
[Show abstract][Hide abstract]ABSTRACT: At present, most part of coast zone in China belong to Case II waters with a large volume of shallow waters. Through theories and experiences of ocean water color remote sensing has a prominent improvement, there still exist many problems mainly as follows: (a) there is not a special sensor for heat pollution of coast water remote sensing up to now; (b) though many scholars have developed many water quality parameter retrieval models in the open ocean, there still exists a large gap from practical applications in turbid coastal waters. It is much more difficult due to the presence of high concentrations of suspended sediments and dissolved organic material, which overwhelm the spectral signal of sea water. Hyperspectral remote sensing allows a sensor on a moving platform to gather emitted radiation from the Earth's surface, which opens a way to reach a better analysis and understanding of coast water. Operative Modular Imaging Spectrometer (OMIS) is a type of representative imaging spectrometer developed by the Chinese Academy of Sciences. OMIS collects reflective and radiation light from ground by RC telescope with the scanning mirror cross track and flight of plane along track. In this paper, we explore the use of OMIS as the airborne sensor for the heat pollution monitoring in coast water, on the basis of an analysis on the mixed-spectrum arising from the image correcting process for geometric distortion. An airborne experiment was conducted in the winter of 2009 on the coast of the East Sea in China.
No preview · Article · Oct 2010 · Proceedings of SPIE - The International Society for Optical Engineering
[Show abstract][Hide abstract]ABSTRACT: A molecular hyperspectral imaging (MHI) system was developed to evaluate the protective effects of erythropoietin (EPO) on early diabetic retinopathy in rats. The system was used to capture hyperspectral images of rat retinal sections selected from three groups: normal control, diabetic, and EPO. Three biochemical parameters were defined, namely, the spectral transmittance index, thickness of outer nuclear layer, and cell area percentage. The corresponding algorithms to calculate these were likewise presented. Experimental results show that, after treatment, the newly defined biochemical parameters of the EPO group become more similar to those of the normal control group compared with those of the diabetic group. This indicates that, to some degree, EPO provides protective effects on the retinal cells of chemically induced diabetic rats after it is injected intravitreally at the onset of diabetes. The results likewise show that the MHI system could provide useful quantitative information regarding retinal sections, which ophthalmologists can use to determine the pathogenesis of diabetic retinopathy and evaluate the protective effect of EPO on diabetic retinal cells.
Full-text · Article · Aug 2010 · IEEE Transactions on Biomedical Engineering
[Show abstract][Hide abstract]ABSTRACT: A combined spectral curve is measured by the traditional field spectrometers in a narrow or wide field range, and the traditional spectral curves are mixed inherently because of the low spatial resolving power. So the mixed spectral pixels were used in the traditional works on the mixed pixel decomposition. A new measure method is proposed to replace the point measurement. The spectral data is captured by the dispersal unit, and one spatial data is from the imaging CCD, and another is captured by the scanning mirror. By the new imaging spectrometer, the target image and spectral curves of every image pixel are captured simultaneously with high spatial resolution. The captured spectral curves could be regarded as the pure curves, which are very useful for the model foundation and analysis of mixed pixel and pixel decomposition. The basic dispersal principle and imaging mode is introduced in this paper. The detailed design is given by the general diagram and the composition figure. The methods and flow chart of the geometric correction and radiometric calibration are discussed in detail. Some experiments are carried out to measure the vegetation and other typical targets, the results of the images and spectral curves are given and discussed.
Preview · Article · Oct 2009 · Proceedings of SPIE - The International Society for Optical Engineering
[Show abstract][Hide abstract]ABSTRACT: Infrared scanner is one of the key payloads of small satellite constellation for environment and disaster monitoring and forecasting (HJ-1 IRS). HJ-1 IRS has four bands including NIR, SWIR, MWIR and LWIR with ground swath of 720 km and spatial resolution of 150 m/300 m. The main mission is the monitoring, prediction and evaluation of natural disaster and environment pollution etc. The special design and fabrication have been made to improve the performance of IRS. The characteristics of the IRS are introduced. Several applications examples are presented.
[Show abstract][Hide abstract]ABSTRACT: A microscopic hyperspectral imager was developed based on the microscopic technology and the spectral imaging technology. Some microscopic hyperspectral images of retina sections of the normal, the diabetic, and the treated rats were collected by the new imager. Single-band images and pseudo-color images of each group were obtained and the typical transmittance spectrums were extracted. The results showed that the transmittance of outer nuclear layer cells of the diabetic group was generally higher than that of the normal. A small absorption peak appeared near the 180th band in the spectrum of the diabetic group and this peak weakened or disappeared in the spectrum of the treated group. Our findings indicate that the microscopic hyperspectral images include wealthy information of retina sections which is helpful for the ophthalmologist to reveal the pathogenesis of diabetic retinopathy and explore the therapeutic effect of drugs.
No preview · Article · Oct 2008 · Science in China Series C Life Sciences
[Show abstract][Hide abstract]ABSTRACT: A hyperspectral tongue imaging system is developed and used in tongue diagnosis. The basic principles and instrumental systems as well as its applications in tongue diagnosis are introduced. A tongue segmentation algorithm which can simultaneously utilizes spectral and spatial information of the hyperspectral tongue images data is also presented. As the wavelength of the hyperspectral tongue images cover the whole visible light, spectrums were used to represent tongue colors and a new algorithm based on Gabor filters was proposed to analyze tongue textures. The experimental results show the hyperspectral tongue imaging system can make much benefit to the computer-aided tongue diagnosis system.
[Show abstract][Hide abstract]ABSTRACT: Tongue inspection is an important diagnostic method in traditional Chinese medicine (TCM). However, due to its qualitative, subjective and experience-based nature, traditional tongue inspection has found very limited application in modem clinical medicine. In this paper, a novel system for tongue inspection based on hyperspectral imaging system is developed. The system includes image acquisition, feature extraction and classification functions. In this system, two kinds of quantitative features, spatial and spectral, are extracted from hyperspectral tongue images by using popular digital image processing techniques. Then, Bayesian networks are employed to model the relationship between these quantitative features and diseases. The preliminary results show that the system is sensitive to the abnormal tongues.
No preview · Article · May 2008 · Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi
[Show abstract][Hide abstract]ABSTRACT: A microscopic pushbroom hyperspectral imaging system was developed based on the microscopic technology and spectral imaging
technology according to the principle of spectral imager in remote sensing. The basic principle and key technologies of this
system were presented and the system performance was also analyzed. Some methods and algorithms were proposed to preprocess
and normalize the microscopic hyperspectral data and retrieve the transmittance spectrum of samples. As a case study, the
microscopic hyperspectral imaging system was used to image the retina sections of different rats and get some significant
results. Experiment results show that the system can be used for the quantitative assessment and evaluating the effect of
medication in biomedical research.
Full-text · Article · Apr 2008 · Chinese Science Bulletin
[Show abstract][Hide abstract]ABSTRACT: To aid ophthalmologists in determining the pathogenesis of diabetic retinopathy and in evaluating the effects of medication, a microscopic pushbroom hyperspectral imaging system is developed. 40 healthy Wistar rats of half gender are selected in this study. They are divided into three groups (six rats failed to be models). 10 normal rats as the normal control group, 12 diabetic rats without any treatment as the model control group, and another 12 diabetic rats treated with LCVS1001 as the LCVS1001 group. The microscopic hyperspectral image of each retina section is collected and processed. Some typical spectrum curves between 400 and 800 nm of the outer nuclear layer are extracted, and images at various wavelengths are analyzed. The results show that a small trough appears near 522.2 nm in the typical spectrum curve of the model control group, and the transmittance of it is higher than that of the normal control group. In addition, the spectrum of the LCVS1001 group changes gradually to the normal spectrum after treatment with LCVS1001. Our findings indicate that LCVS1001 has some therapeutic effect on the diabetic retinopathy of rats, and the microscopic pushbroom hyperspectral imaging system can be used to study the pathogenesis of diabetic retinopathy.
Full-text · Article · Nov 2007 · Journal of Biomedical Optics
[Show abstract][Hide abstract]ABSTRACT: A scientific goal of the moon exploration project is to perform elemental analysis on the moon surface. The assuming of using laser-induced breakdown spectroscopy (LIBS) for this goal has been put forward. The laser plasma used by LIBS is sensitive to the surrounding atmosphere and the moon has very low ambient gas pressure on the surface, so the study of the LIBS capabilities at the low pressure was carried out.
Full-text · Article · Jan 2007 · Chinese Optics Letters
[Show abstract][Hide abstract]ABSTRACT: In view of the problems existing in GPS, a non-gyroscope DR is introduced. The operating principle and the algorithm of the GPS/DR device are also presented. By operating measured data synthetically, linear observation equations are obtained for the information fusion algorithm. This approach avoids model error due to linearizing nonlinear observation equations in the conventional algorithm, so that the stability of information fusion algorithm is improved and computation expenses are reduced. Field running experiments show that satisfactory accuracy can be obtained by the proposed navigation model and algorithm for the non-gyroscope GPS/DR device.
No preview · Article · Jun 2006 · Journal of Systems Engineering and Electronics
[Show abstract][Hide abstract]ABSTRACT: Imaging spectrometer is characteristic of high spectral resolution, high spatial resolution, multitudinous bands and mass data. The ground object information of hyperspectral image can be used on target identification. On the base of theory on hyperspectral remote sensing imaging technology, the paper mainly introduces three spectrometers designed by Shanghai Institute of Technical Physics, CAS. There are CMODIS, which is the main payload of SZ-3 spaceship, OMIS and PHI, which are airborne sensors. Some applications about those sensors are discussed in the end.
No preview · Article · Jan 2005 · Proceedings of SPIE - The International Society for Optical Engineering