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	Consistency Analysis and Accuracy Assessment of Three Global Ten-Meter Land Cover Products in Rocky Desertification Region-A Case Study of Southwest China 期刊论文 OAI收割 ISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION, 2022, 卷号: 11, 期号: 3, 页码: 25 作者: Wang, Jun; Yang, Xiaomei; Wang, Zhihua; Cheng, Hongbin; Kang, Junmei \| 收藏 \| 浏览/下载：35/0 \| 提交时间：2022/09/21 rocky desertification land cover products 10 m resolution spatial consistency accuracy evaluation southwest China
	Comparison of Three Ten Meter Land Cover Products in a Drought Region: A Case Study in Northwestern China 期刊论文 OAI收割 LAND, 2022, 卷号: 11, 期号: 3, 页码: 20 作者: Kang, Junmei; Yang, Xiaomei; Wang, Zhihua; Cheng, Hongbin; Wang, Jun \| 收藏 \| 浏览/下载：29/0 \| 提交时间：2022/09/21 land cover products 10 m resolution spatial consistency accuracy evaluation drought regions northwestern China
	Consistency Analysis and Accuracy Assessment of Three Global Ten-Meter Land Cover Products in Rocky Desertification Region-A Case Study of Southwest China 期刊论文 OAI收割 ISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION, 2022, 卷号: 11, 期号: 3, 页码: 25 作者: Wang, Jun; Yang, Xiaomei; Wang, Zhihua; Cheng, Hongbin; Kang, Junmei \| 收藏 \| 浏览/下载：31/0 \| 提交时间：2022/09/21 rocky desertification land cover products 10 m resolution spatial consistency accuracy evaluation southwest China
	Comparison of Three Ten Meter Land Cover Products in a Drought Region: A Case Study in Northwestern China 期刊论文 OAI收割 LAND, 2022, 卷号: 11, 期号: 3, 页码: 20 作者: Kang, Junmei; Yang, Xiaomei; Wang, Zhihua; Cheng, Hongbin; Wang, Jun \| 收藏 \| 浏览/下载：27/0 \| 提交时间：2022/09/21 land cover products 10 m resolution spatial consistency accuracy evaluation drought regions northwestern China
	Design of the real-time autofocusing system for collimator with long focus length and large aperture (EI CONFERENCE) 会议论文 OAI收割 2011 International Academic Conference on Numbers, Intelligence, Manufacturing Technology and Machinery Automation, MAMT 2011, December 24, 2011 - December 25, 2011, Wuhan, China 作者: Zhang X.; Zhang X.; Zhang X. 收藏 \| 浏览/下载：40/0 \| 提交时间：2013/03/25 Large aperture collimator which has been widely used for calibrating and testing various optical devices plays an essential role in correlative laboratories. As being the basic testing and calibration equipment the large aperture collimator's accuracy should be much higher than the device under testing in order to ensure the accuracy of the measurement. However the process of adjusting the collimator is extremely complicated due to the collimator's large aperture and long focal length. So it is difficult to ensure the measurement's quality and easy to cause the system being vulnerable to the surrounding environment. One of the most common problems is defocus. In order to solve the problem above this issue presents a new type of autocollimator autofocusing system which uses pentaprism instead of using large-aperture plane mirror semiconductor lasers as light source and CCD sensor as receiver. The system is smaller lighter and more convenient when using. The computer simulation shows that the autofocusing system's resolution could reach the accuracy of 40m. If we use the relevant algorithms to execute the sub-pixel scanning the resolution could reach the accuracy of 10m. It shows that the system could satisfy the required testing precision of testing large aperture optical device.
	Optical system design with high resolution and large field of view for the remote sensor (EI CONFERENCE) 会议论文 OAI收割 Chang J.; Weng Z.-C.; Wang Y.-T.; Cheng D.-W.; Jiang H.-L. 收藏 \| 浏览/下载：29/0 \| 提交时间：2013/03/25 In this paper we are presenting a design method and its results for a space optical system with high resolution and wide field of view. This optical system can be used both in infrared and visible configurations. The designing of this system is based on an on-axis three-mirror anastigmatic (TMA) system. Here the on-axis concept allows wide field of view (FOV) enabling a diversity of designs available for the Multi-Object Spectrometer instruments optimized for low scattered and low emissive light. The available FOVs are upto 1 in both spectrum ranges whereas the available aperture range is F/15 - F/10. The final optical system is a three-mirror telescope with two on-axis and one off-axis segment and its resolution is 0.3m or even lower. The distinguished feature of this design is that it maintains diffraction-limited image at wide wavelengths. The technological developments in the field of computer generated shaping of large-sized optical surface details with diffraction-limited imagery have opened new avenues towards the designing techniques. Such techniques permit us to expand these technological opportunities to fabricate the aspherical off-axis mirrors for a complex configuration.
	Development of an experimental EUVL system (EI CONFERENCE) 会议论文 OAI收割 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Design, Manufacturing, and Testing of Micro- and Nano-Optical Devices and Systems, July 8, 2007 - July 12, 2007, Chengdu, China 作者: Wang L.-P.; Zhang L.-C.; Jin C.-S. 收藏 \| 浏览/下载：17/0 \| 提交时间：2013/03/25 An experimental EUVL system has been developed to investigate EUV imaging system design component fabrication assembly technique and experimental process. The system includes a laser produced plasma (LPP) source an ellipsoidal condenser a transmission mask a reduced projection optics and vacuum system. We designed a 10:1 reduction projection optics using Schwarzschild system with spherical mirrors to achieve 0.1m resolution. The Schwarzschild optics coated with Mo/Si multilayers was assembled with wavefront error (WFE) of 0.014 waves RMS at 632.8nm wavelength under computer-aided alignment method. Using this system a fine pattern of less than 0.25m covering a 0.1mm diameter image field of view was clearly replicated on resist-coated wafer.
	A new spaceborne compression approach for remote sensing imagery (EI CONFERENCE) 会议论文 OAI收割 ICO20: Remote Sensing and Infrared Devices and Systems, August 21, 2005 - August 26, 2005, Changchun, China 作者: Xu S. 收藏 \| 浏览/下载：25/0 \| 提交时间：2013/03/25 After analyzing advantages and disadvantages of these typical encoding methods: SPIHT and VQ a "DWT+MRLE" approach for spaceborne data compression was proposed in this paper. This approach includes two steps: Discrete Wavelet Transform (DWT) and Modified Run Length Encoding (MRLE). The former used CDF9/7 biorthogonal wavelet filters to powerfully get rid of correlation between pixels in imagery. The later put enlightening information into the lowest bit of some key-position transform coefficients. Consequently CDF9/7 and MRLE together make hardware platform remain high real-time capability and help reconstructed images keep good fidelity with PSNR being about 40dB compared with the original ones. Comparison between experimentations on SPOT4's low-spatial-resolution (10m) imagery and Ikonos2's high-spatial-resolution (1m) imagery shows this "DWT+MRLE" method having better performance for remote-sensed imagery especially those of higher resolution. Although inferior to 8:1 Compression Ration (CR) here near 5:1 is greater than France SPOT5's 3:1 and American Ikonos2's 11:2.6 on-board data compression. More important this method having less computational amount is good for spaceborne capability of real time. The consumed time of different image size is also presented in this paper based on TI TMSC6416 DSP chip with 600MHz CPU cycle clock.
	Self Imaging technique for refocusing an aerospace camera (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Devices and Instruments, August 21, 2005 - August 26, 2005, Changchun, China 作者: Li W.; Li W.; Wang X.; Wang X.; Wang X. 收藏 \| 浏览/下载：33/0 \| 提交时间：2013/03/25 A novel auto-focusing technique using a self imaging approach is developed for an aerospace camera having large aperture and long focus. Its optical system consists of an emitting system receiving system and two penta-prisms. Emitting system has three parts: a light source beamsplitter and aim slit. The receiving system includes a field lens two separate lenses and CCD. Using two little penta-prisms instead of a large planar mirror makes the autofocus system simple and compact. CCD was used as photoelectric converting device. A defocused signal is acquired by measuring the change of the two slit self-images position imaged on the CCD. A simple and compact construction of the auto-focusing system was proposed. The algorithm to calculate the moving of the slit-self images position was analyzed in order to achieve subpixel position estimation. The results of the experiments show a 10m focusing precision. The system demonstrates high resolution easy adjustment and high reliability.