Verification and recalibration of HY-2A microwave radiometer brightness temperature

HY-2A is the first one of the Chinese HY-2 ocean satellite series carrying a microwave radiometer(RM)to measure sea surface temperature,sea surface wind speed,atmospheric water vapor,cloud liquid water content,and rain rate.We verified the RM level 1B brightness temperature(T B)to retrieve environmental parameters.In the verification,TB that simulated using the ocean-atmosphere radiative transfer model(RTM)was used as a reference.The total bias and total standard deviation(SD)of the RM level 1B TB,with reference to the RTM simulation,ranged-20.6-4.38 K and 0.7-2.93 K,respectively.We found that both the total bias and the total SD depend on the frequency and polarization,although the values for ascending and descending passes are different.In addition,substantial seasonal variation of the bias was found at all channels.The verification results indicate the RM has some problems regarding calibration,e.g.,correction of antenna spillover and antenna physical emission,especially for the 18.7-GHz channel.Based on error analyses,a statistical recalibration algorithm was designed and recalibration was performed for the RM level 1B TB.Validation of the recalibrated TB indicated that the quality of the recalibrated RM level 1B TB was improved significantly.The bias of the recalibrated T B at all channels was reduced to<0.4 K,seasonal variation was almost eradicated,and SD was diminished(i.e.,the SD of the 18.7-GHz channel was reduced by more than 0.5K).

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2010(2010 No.131)

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China has approved the following 8 national measuring verification regulations in 2010 and publicize now.

A Novel Verification Development Platform for Passive UHF RFID Tag

This paper introduces a novel verification development platform for the passive UHF RFID tag,which is compatible with the ISO/IEC 18000-6B standard,operating in the 915MHz ISM band. This platform efficiently reduces the design and development time and cost, and implements a fast prototype design of the passive UHF RFID tag. It includes the RFID analog front end and the tag control logic, which is implemented in an Altera ACEX FPGA. The RFID analog front end, which is fabricated using a Chartered 0.35μm two-poly four-metal CMOS process, contains a local oscillator, power on reset circuit, matching network and backscatter, rectifier, regu- lator,AM demodulator, etc. The platform achieves rapid, flexible and efficient verification and development, and can also be fit for other RFID standards after changing the tag control logic in FPGA.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2008 2008 NO.35

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China has approved the following 11 national measuring verification regulations in 2008 and publicize now.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2008

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China hasapproved the following 24 national measuring verification regulations in 2008 and publicize now.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2008 2008 No.22

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China has approved the following 10 national measuring verification regulations in 2008 and publicize now.

STRUCTURAL PARAMETERS CALIBRATION BY POSTURE MEASUREMENT ON PARALLEL 6-DOF PLATFORM

Some approaches to measure parallel 6-degree of freedom platform's posturestatically and to calibrate the platform's actual structural parameters by measuring a series of theplatform's varying postures are studied. In the case where high posture accuracy is requiredrelatively, to obtain the platform's actual structural parameters is very important. Threedimensions measurement with 2 theodolites are used to obtain the platform's postures statically andNewton iterative method is adopted to calibrate structural parameters. Some measures taken in themeasurement and the calibration are discussed in detail. And the experiment results of theplatform's posture control before and after the calibration are given. The results show that theplatform's posture control accuracy after the calibration is improved notably.

Reliability-Based Load and Resistance Factors Design for Offshore Jacket Platforms in the Bohai Bay:Calibration on Target Reliability Index

The target reliability index has been effectively used as the best solution to deal with the relationship between the structural safety and the optimal economy in any structural design. However, the target reliability index for offshore jacket platforms based on different sea areas in China has never been calibrated. This paper presents an approach for its calibration, and suggests many kinds of associated load cases. The uncertainties of loads and structural resistance are mainly in- vestigated. The target reliability index for structural components, tubular joints and piles of offshore jacket plaffortns are discussed respectively in detail. Finally, through the calibrated results from the offshore jacket platforms of QK18-1, JZ20-2, SZ36-1 and BZ28-1 in the Bohai Bay, it is proposed to adopt 2.8 as the target reliability index of offshore jacket platforms in the Bohai Bay for a 25-year design period. The results provide significant reference for the design of offshore jacket platforms.

Reliability-Based Load and Resistance Factors Design for Offshore Jacket Platforms in the Bohai Bay:Calibration on Design Factors

For the fulfillment of the probability-based structural design for the offshore jacket platforms in the Bohai Bay, the design factors of loads, resistance and load combinations are much necessary to be calibrated according to the proposed target reliability index. Firstly, the limit states function for the offshore jacket platforms is introduced. Then, four approaches to calibrate the factors of load and resistance are presented and compared. Afterwards, the methods to calibrate the load combination factors are developed. Finally, the factors of load, resistance and load combination for the offshore jacket platforms in the Bohai Bay are calibrated and the corresponding design formulae are recommended. The results are proved to be rational in practice, and also illustrate that the proposed target reliability index for offshore jacket platforms in the Bohai Bay is also appropriate.

A Matlab/Simulink Development and Verification Platform for a Frequency Estimation System

The precise estimation of the frequency of the signal is of great significance in the Radar system, the electronic warfare system and many other systems. In this paper, we propose a development and verification platform for the frequency estimation system in the Matlab and Simulink environment. Its open-extensibility architecture enables the performance evaluation of different frequency estimation algorithms and its graphic interface can greatly promote the system design, simulation and verification efficiency.

Error Coefficient Estimation of Inertial Platform in Its Calibration

The error coefficient estimation of inertial platform in the course of its consecutive ground calibration is studied.A separate-bias algorithm is adopted to estimate the error parameters effectively. The ill-conditioning problem of the equation solution caused by the huge state dimension is also resolved. And the simulation result shows its validity.

Preliminary proposal of scientific data verification in CSES mission

China Seismo-Electromagnetic Satellite （CSES） will be launched at the end of 2016 and the orbit is sun- synchronous and the altitude is about 500 km. The design of CSES satellite and ground segment are introduced in this paper first. And then the preliminary proposals of scientific data verification and cross-verification in CSES mission are given, which can be used to classify the payloads＇ operation state, and validate the reliability of data.

面向SoC系统的可扩展UVM自动化验证平台

得益于设计IP的成熟可靠性,目前SoC系统能够基于设计IP实现快速构建。在SoC系统构建过程中,往往需要考虑从IP模块到SoC系统的功能验证。为了能够减小SoC系统构建与功能验证之间的项目压力,提出了一种可快速构建、可扩展、可复用的自动化验证平台。该平台基于UVM、Python、Mako技术,同时具备SV、UVM、C的测试能力,可以快速部署验证平台,有利于验证环境,标准化测试指令规范了测试代码。在不同验证层次中投入试用,有效节省了96.9%的构建测试平台时间,减少了66.2%的测试框架代码,减少了66.4%的测试用例代码。该平台已作为独立EDA产品,参与到多个芯片研发。

智能机舱验证平台设计与开发

智能机舱是近年来提出的概念,目前尚处于初级阶段,其功能,如数据采集、特征提取,以及故障诊断等的准确性尚缺乏规范性的验证手段。以某型内河船舶机舱动力系统为对象,基于NI LabVIEW软件平台和现场可编程门阵列硬件开发智能机舱验证平台,结合监测设备工作过程机理,按信号特征、通道,以及接口一致的原则,模拟输出柴油机、辅助发电机、齿轮箱和轴系等设备各类监测信号。通过开发的控制软件,可实现标准的、故障的和设备性能衰退的3类信号输出,为智能机舱系统数据采集、信号特征提取、监测诊断算法,以及健康状态评估算法的准确性和实时性提供验证平台。

一种基于UVM的USB接口验证平台设计

随着集成电路的发展,电子设备变得越来越复杂,对于通用串行总线(Universal Serial Bus,USB)接口的验证来说,传统的验证方法已经无法满足需求。使用通用验证方法学(Universal Verification Methodology,UVM)验证平台可以提高验证效率,减少人工操作和误差,保证USB设备的品质和可靠性。本文介绍了一种基于UVM的USB接口验证平台设计,该平台可以对USB接口进行模块化和可重用性设计,支持自动化测试流程,测试数据的收集和分析等功能。通过应用UVM验证平台,针对USB接口传输方式对其单次传输过程进行封装并继承使用,加速USB设备的开发和测试进程,提高产品质量和生产效率。实验结果表明,与传统的验证方法相比,使用UVM验证平台可以显著提高验证效率和精度。此外,该平台还具有高可靠性和高可维护性,可广泛应用于各种USB设备的开发与生产过程中。

高效型SCR尿素计量泵精度标定台方案设计

SCR技术已成为柴油车降低NOX排放的主流技术方法。尿素泵作为SCR系统的核心部件之一,其计量精度直接影响系统运行效率。针对传统的尿素泵标定方法的不足,提出一种基于微小椭圆齿轮流量计的尿素计量泵精度标定台,设计了气助型和非气助型尿素泵标定方案,对于无回流型尿素计量泵,可采用单流量计装在吸液管上直接测量。对于有脉动强且有回流的尿素计量泵,使用“减重”法测量,在吸液管与回液管各安装一个椭圆齿轮流量计,通过差值的办法得到尿素喷射量。经过实践,实时性强,精度高。

基于标定和计算的电子射野影像系统剂量重建

提出了一种基于标定和计算的电子射野影像系统(EPID)剂量重建算法。首先,对连续采集模式的EPID原始数据进行暗场校正和增益校正,然后通过亮场灰度特征确定射野边界。其次,对EPID数据进行MU标定、离轴标定和射野大小标定,并根据标定后的叠加通量和加速器机头蒙特卡罗模型进行剂量重建。最后,选取9例IMRT计划,分别使用EPID和MapCheck对计划进行验证测量,并在不同γ标准下比较两种验证工具的通过率。针对选取的1例计划病例,两种标准下使用MapCheck对多个病例验证的通过率分别为99.02%±1.28%、90.84%±4.49%;使用EPID重建模型的平均通过率分别为98.86%±1.19%、91.39%±4.80%。本文提出的标定和剂量计算相结合的EPID重建算法,与主流剂量验证软件MapCheck相比,对IMRT计划的验证通过率没有统计学差异(P>0.05),符合剂量验证的临床要求。

无人水面艇路径规划与控制实验平台研究

针对无人艇路径规划与避障控制等功能在真实环境下系统验证和评估不足的问题,提出一种具备多种传感器和控制系统的无人滑行艇实验平台。文中所开发的实验平台集成激光雷达、深度相机、全球定位系统(global positioning system,GPS)、超宽带(ultra wide band,UWB)定位系统、陀螺仪等多种传感器,并采用基于机器人操作系统(robot operating system,ROS)和Free_RTOS操作系统的主控制器和底层控制器。该实验平台不仅包括滑行艇本身、感知系统、底层控制器和远程监控系统等,还包括上层定位算法、路径规划算法和执行器控制算法。文中以1艘装载了多种传感器的无人滑行艇为实验对象,搭建了包括建图、定位与远程监控的综合实验平台,并且进行了滑行艇导航实验,验证了路径规划和避障控制算法的有效性,可为无人艇的技术发展和应用提供一定的参考。

考虑台风事件影响的日降水预报检验与订正

【目的】台风带来的强降水常给当地带来洪涝等灾害,在台风事件下提供准确可靠的降水预报是科学研究和业务预报的重要工作。【方法】通过台风路径缓冲区筛选台风场次,检验台风事件和非台风事件分布情况;对美国国家环境预报中心提供的GEFSv12逐日原始降水预报检验数据精度情况,评价原始预报技巧;应用伯努利-伽马-高斯模型对GEFSv12降水预报,在我国粤港澳大湾区格点,设计不同订正方案,在不同降水场景下,评估不同情况下模型订正前后预报性能。【结果】影响我国东南沿海台风登陆时间主要集中于7—9月,台风等级集中在14级以前;台风事件下,利用台风事件样本训练模型订正后预报BIAS接近0,排序概率技巧得分CRPSS平均提高了近15%,α-index相对原始预报提升了约0.16。【结论】伯努利-伽马-高斯模型能有效订正原始预报存在的系统偏差,提高预报的准确性;不同降水场景订正效果有所区别,对出现极值降水较少的非台风事件,订正后效果有更好的表现;台风事件下,利用台风样本训练模型订正效果相对较好,提高了原始预报精度技巧、可靠性,减少预报偏差;订正的效果和相关系数大小有关,相关系数表现好的区域有更好的预报精度技巧得分,经订正后有利于后续水文集合预报应用、模型发展和备灾应灾工作。