Liang H.,Beijing Orient Institute of Measurement and Test
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010
Precision through-lines, coaxial airlines, are the most accurate microwave impedance standards. They are widely applied in the TRL calibration method. The air-lines are also important standards which are used to test network analyzer systems. In addition, the scattering parameter and uncertainty of coaxial air-line are important for improving the accuracy of VNA. However, the conventional microwave measurement systems have limitations in observing and obtaining accurate information of the performance of coaxial air-lines. In this paper, a new approach is proposed that determines microwave scattering parameter by physical components and assumed models. Experimental results demonstrate the efficacy of the proposed algorithm in comparison to the experimental results obtained from microwave measurement. In addition, the estimated uncertainty is also presented. © 2010 SPIE.
Min L.,Beijing Orient Institute of Measurement and Test
2014 31th URSI General Assembly and Scientific Symposium, URSI GASS 2014 | Year: 2014
Here distinguish concept of electrostatic capacitance from alternating current (Ac) capacitance, and give a calibration method for electrostatic capacitance. Considering a capacitor, there are two values of Ac and electrostatic capacitance. Both values are same only under ideal condition, yet are difference in actual conditions of considering series and parallel resistance. Two rules must be obeyed when tracing the electrostatic capacitance to Ac capacitance standard. Other than the method of using voltage source and Coulomb meter, a new measurement method is put forward by paralleling a known capacitor to calculate unknown capacitance. For instance to calibrate a metal plate capacitance on a kind of instrument named Charged Plate Monitor (CPM, also called Charge Analyzer), The measurement uncertainty is about 2%. © 2014 IEEE.
Liu F.,Yanshan University |
Zhao Y.,Yanshan University |
Yang Y.,Beijing Orient Institute of Measurement and Test |
Wen Y.,Yanshan University
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2014
The high-altitude balloon calibration solar cell is the standard cell which can be used for the ground sun simulator and light detection. This paper presents a control method of sun tracking for solar cell calibration at a high altitude by the flying Balloons. The paper gives the design of hardware and software of the solar tracking, hybrid automatic tracking control strategy, altitude tracking control problem solving, and the result of solar tracking in high-altitude simulation environment test. Mearwhile, the key technical problems in the high-altitude ballon calibration solar cell tracking control system under extreme environment is solved, such as reliability, continuous tracking and anti-shake in extreme environments. In the experiment, the balloon flight level is 32 km, flying time is more than 2 h, and the deviation of solar tracking is less than 1°. A preliminary analysis shows that the results of solar calibration test are reasonable and reliable, which provides a new idea for the study of high-altitude balloon AM0 solar cell calibration with sun tracking control method. ©, 2014, Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica. All right reserved.
Sun W.,Beijing Orient Institute of Measurement and Test
Advanced Materials Research | Year: 2013
To address the problems of low efficiency, high cost and low automatic level existing in traditional laser tracking measurement systems, a laser tracking-vision guiding measurement system for large-scale parts assembly is introduced in this paper. The system is composed of mono-camera and a laser tracker, can fulfill real-time tracking and automatic measurement throughout the whole assembly process. A global calibration method based on public planes and a method for finding the 3D positions of the target reflectors based on monocular vision measuring are expounded. Mathematical model is established, measurement system is built, and the experiment is accomplished. The experiment result indicates that the proposed system features relative high degree of automation and high measuring speed, has future in practical application. © (2013) Trans Tech Publications Switzerland.
Bai X.,Beijing Orient Institute of Measurement and Test |
Zhang Y.,Beijing Orient Institute of Measurement and Test
Proceedings - IEEE 2011 10th International Conference on Electronic Measurement and Instruments, ICEMI 2011 | Year: 2011
A control software is designed for a data management equivalent device about the calibration. As a new design method, it is to add self-calibration method to data management equivalent device of satellite, making the calibration into the device itself, which improves the dependability of the system. Research on the self-calibration function, it is used the least square basic principle to curve fitting for calibrating the AD of the hardware, and improve sampling resolution. On the basis of the average segmentation of parameter calibration, which could improve the accuracy of the test for the device. The paper expounded the designing to software. The designing indicates that the calibration can fulfill the equivalent device, reasonable designing of the software. © 2011 IEEE.