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Simulation of FY-2D infrared brightness temperature and sensitivity analysis to the errors of WRF simulated cloud variables

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Science China Earth Sciences 2018年第7期61卷 957-972页

作者： Xiaokang SHI Yaodong LI Jianwen LIU Xizi XIANG Le LIU Beijing aviation Meteorological institute Beijing 100085China Guizhou Sub-bureau of Southwest Air Traffic Management Bureau of Civil aviation of China Guiyang 550002China Guangxi Meteorological Observatory Nanning 530022China

This study simulated FY-2 D satellite infrared brightness images based on the WRF and RTTOV models. The effects of prediction errors in WRF micro-and macroscale cloud variables on FY-2 D infrared brightness temperature accuracy were analyzed. The principle findings were as follows. In the T+0–48 h simulation time, the root mean square errors of the simulated brightness temperatures were within the range 10–27 K, i.e., better than the range of 20–40 K achieved previously. In the T+0–24 h simulation time, the correlation coefficients between the simulated and measured brightness temperatures for all four channels were >0.5. The simulation performance of water channel IR3 was stable and the best. The four types of cloud microphysical scheme considered all showed that the simulated values of brightness temperature in clouds were too high and that the distributions of cloud systems were incomplete, especially in typhoon areas. The performance of the THOM scheme was considered best, followed in descending order by the WSM6, WDM6, and LIN schemes. Compared with observed values, the maximum deviation appeared in the range 253–273 K for all schemes. On the microscale, the snow water mixing ratio of the THOM scheme was much bigger than that of the other schemes. Improving the production efficiency or increasing the availability of solid water in the cloud microphysical scheme would provide slight benefit for brightness temperature simulations. On the macroscale, the cloud amount obtained by the scheme used in this study was small. Improving the diagnostic scheme for cloud amount, especially high-level cloud, could improve the accuracy of brightness temperature simulations. These results could provide an intuitive reference for forecasters and constitute technical support for the creation of simulated brightness temperature images for the FY-4 satellite.

关键词： FY-2D RTTOV WRF Simulated brightness temperature Cloud amount Cloud microphysics scheme TyphoonMatmo

Speckle suppressing based on morphological filter and fuzzy logic

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Chinese Optics Letters 2003年第12期1卷 689-691页

作者：蒋立辉任德明鲁旭虎 institute of Communication and Information Processing Civil Aviation University of China Tianjin 300300 institute of Opto-Electronics Harbin Institute of Technology Harbin 150001

A novel morphological filtering algorithm is proposed for suppressing speckle noise in images. The algorithm employs directional morphological close-open and open-close operations, then computing the membership of the filtered versions' every pixel according to the designed fuzzy rule. The final filtered image is composed of all the pixels with corresponding maximal membership. The validity of the algorithm is demonstrated.

关键词： Fuzzy sets Speckle

RETRIEVING ATMOSPHERIC SOUNDING PROFILES AROUND TYPHOON YUNNA USING INFRARED HYPERSPECTRAL MEASUREMENTS AIRS

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Journal of Tropical Meteorology 2010年第3期16卷 201-209页

作者：黄兵刘建文白杰李耀东高守亭 School of Physics Peking University aviation institute of Air Force institute of Atmospheric Sciences Chinese Academy of Sciences

In this study,we derived atmospheric profiles of temperature,moisture,and ozone,along with surface emissivity,skin temperature,and surface pressure,from infrared-sounder radiances under clear sky (cloudless) *** were detected objectively using the Atmospheric Infrared Sounder under a relatively low spatial resolution and cloud-mask information from the Moderate Resolution Imaging Spectroradiometer under a high horizontal resolution;this detection was conducted using space ***’s nonlinear physical iterative solution technique is applied to the radiative transfer equation (RTE) to retrieve temperature profiles,relative humidity profiles,and surface variables *** technique is carried out by using the results of an eigenvector regression retrieval as the background profile and using corresponding iterative forms for the weighting functions of temperature and water-vapor mixing *** iterative forms are obtained by applying the variational principle to the *** also compared the retrievals obtained with different types of *** results show that the retrieved atmospheric sounding profile has great superiority over other observations by accuracy and *** profiles can be used to improve the initial conditions of numerical models and used in areas where conventional observations are sparse,such as plateaus,deserts,and seas.

关键词： infrared remote sensing retrieval atmospheric sounding profile MODIS AIRS

Adaptive Human Tracking Across Non-overlapping Cameras in Depression Angles

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Transactions of Nanjing University of Aeronautics and Astronautics 2015年第1期32卷 48-60页

作者：邵荃梁斌斌朱燕张海蛟陈涛 College of Civil aviation Nanjing University of Aeronautics and Astronautics institute of Public Safety Research Tsinghua University

To track human across non-overlapping cameras in depression angles for applications such as multi-airplane visual human tracking and urban multi-camera surveillance,an adaptive human tracking method is proposed,focusing on both feature representation and human tracking *** representation describes individual by using both improved local appearance descriptors and statistical geometric *** improved feature descriptors can be extracted quickly and make the human feature more *** human tracking mechanism is based on feature representation and it arranges the human image blobs in field of view into *** appearance models are created to include the maximum inter-camera appearance information captured from different visual *** persons appeared in camera are first filtered by statistical geometric *** the one among the filtered persons who has the maximum matching scale with the primary models is determined to be the target ***,the image blobs of the target person are used to update and generate new primary appearance models for the next camera,thus being robust to visual angle *** results prove the excellence of the feature representation and show the good generalization capability of tracking mechanism as well as its robustness to condition variables.

关键词： adaptive human tracking appearance features geometric features non-overlapping camera depression angle

An Investigation into the Relationship between Surface Rain Rate and Rain Depth over Southeast Asia

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Advances in Atmospheric Sciences 2013年第1期30卷 142-152页

作者：胡亮李耀东邓涤菲 National Satellite Meteorological Center China Meteorological Administration institute of Atmospheric Physics Chinese Academy of Sciences Beijing aviation Meteorological institute

The relationship between surface rain rate and depth of rain system （rain depth） over Southeast Asia is examined using 10-yr Tropical Rainfall Measuring Mission （TRMM） precipitation radar （PR） measurements. Results show that, in general, a large surface rain rate is associated with a deep precipitating system, but a deep rain system may not always correspond with a large surface rain rate. This feature has a regional characteristic, Convective rain develops more frequently over land than over the ocean, while stratiform rain can extend to higher altitudes over the ocean than over land. A light surface rain rate has the largest probability to occur, regardless of rain depth. A convective rain system is more likely associated with a stronger surface rain rate than a stratiform rain system. Results show that precipitation systems involve complex microphysical processes. Rain depth is just one characteristic of precipitation. A linear relationship between surface rain rate and rain depth does not exist. Both deep convective and stratiform rain systems have reflectivity profiles that can be divided into three sections. The main difference in their profiles is at higher levels, from 4.5 km up to 19 km. For shallow stratiform rain systems, a two-section refiectivity profile mainly exists, while for convective systems a three-section profile is more common.

关键词： TRMM rain depth convective rain stratiform rain

Beam-pointing error compensation method of phased array radar seeker with phantom-bit technology

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Chinese Journal of Aeronautics 2017年第3期30卷 1217-1230页

作者： Qiuqiu WEN Tianyu LU Qunli XIA Zedong SUN School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Aerospace Automatic Control institute Beijing 100854China Army aviation institute Beijing 100041China

A phased array radar seeker（PARS） must be able to effectively decouple body motion and accurately extract the line-of-sight（LOS） rate for target missile *** this study,the realtime two-channel beam pointing error（BPE） compensation method of PARS for LOS rate extraction is *** PARS discrete beam motion principium is analyzed,and the mathematical model of beam scanning control is *** to the principle of the antenna element shift phase,both the antenna element shift phase law and the causes of beam-pointing error under phantom-bit conditions are analyzed,and the effect of BPE caused by phantom-bit technology（PBT） on the extraction accuracy of the LOS rate is examined.A compensation method is given,which includes coordinate transforms,beam angle margin compensation,and detector dislocation angle *** the method is used,the beam angle margin in the pitch and yaw directions is calculated to reduce the effect of the missile body disturbance and to improve LOS rate extraction precision by compensating for the detector dislocation *** simulation results validate the proposed method.

关键词： Beam-pointing error Beam scanning control Line-of-sight rate extraction Phantom-bit technology Phased array radar seeker

Formation and mechanical properties of bulk Cu-Ti-Zr-Ni metallic glasses with high glass forming ability

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中国有色金属学会会刊：英文版 2007年第1期17卷 16-20页

作者：杨英俊康福伟邢大伟孙剑飞沈庆克沈军 School of Materials Science and Engineering Harbin Institute of Technology Department of Mechanical Engineering Aviation University of Air Force

Bulk amorphous Cu52.5Ti30Zr11.5Ni6 and Cu53.1Ti31.4Zr9.5Ni6 alloys with a high glass forming ability can be quenched into single amorphous rods with a diameter of 5 mm, and exhibit a high fracture strength of 2 212 MPa and 2 184 MPa under compressive condition, respectively. The stress—strain curves show nearly 2% elastic strain limit, yet display no appreciable macroscopic plastic deformation prior to the catastrophic fracture due to highly localized shear bands. The present work shows clearly evidence of molten droplets besides well-developed vein patterns typical of bulk metallic glasses on the fracture surface, suggesting that localized melting induced by adiabatic heating may occur during the final failure event.

关键词：金属玻璃成形能力机械性能绝热升温合金

Robust design and analysis of a conformal expansion nozzle with inverse-design idea

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Chinese Journal of Aeronautics 2018年第1期31卷 79-88页

作者： Wenbiao GAN Xiaocui ZHANG Tielin MA Qinling ZHANG Wu YUAN Research institute of Unmanned System Beihang University The First Aircraft institute Aviation Industry Corporation of China Computer Network Information Center Chinese Academy of Sciences

This paper examines robust optimization design and analysis of a conformal expansion nozzle of flying wing Unmanned Aerial Vehicle （UAV） with the inverse-design idea. In view of flow features and stealth constraints, the inverse-design idea is described and the uncertainty-based robust design model is presented. A robust design system employs this model to combine deterministic optimization and robust optimization and is applied into design of a conformal expansion nozzle. The results indicate that design optimization can conform to the anticipation of the inversedesign idea and significantly improve the aerodynamic performance that meet the requirement of 6σ. The present method is a feasible nozzle design strategy that integrates robust optimization and inverse-design.

关键词： Aerodynamic analysis Inverse-design Nozzle Off-design Robust optimization

Real-time target recognition system simulation based on laser near-field detection

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Optoelectronics Letters 2009年第4期5卷 299-303页

作者：于晓亮马惠敏肖剑 Department of Electronic Engineering Tsinghua University Department of Airborne Equipment Army Aviation Institute Army aviation Military Delegate Bureau Headquarters of the General Staff

This paper constructs a simulation system of near-field laser imaging for 3D grid model of target,provides some methods for the key problems,such as the modeling of target and laser transceiver,the calculation of laser echo power,the imaging algorithms and so on.A target image library is established by a new imaging method in any rendezvous *** four real-time recognition algorithms which are efficient and suitable for hardware implementation are presented at the conditions of the image incompleteness,intensive noise and arbitrary attitude of *** experimental results show that all the four algorithms can independently recognize the target effectively and a better recognition effect is obtained by the integration of four algorithms.

关键词：实时目标识别激光成像系统仿真 experimental 近场检测网格模型仿真系统