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Quantum Precision Measurement Technology and Its Typical Applications in Measurement Field GE Meng, ZHANG Tie-li, LIU Hao, SONG Yan, WU Chen Journal of Astronautic Metrology and Measurement    2023, 43 (6): 1-6.   DOI: 10.12060/j.issn.1000-7202.2023.06.01 Abstract （313）      PDF（pc） （4203KB）（1650）       Knowledge map    Save Quantum precision measurement is based on the basic principle of quantum mechanics by using the interaction between light，atoms and magnetic field to measure physical quantities.The concept of quantum precision measurement and the technical principles in quantum precision measurement are described as a starting point,and typical applications of quantum precision measurement technology in the field of measurement are investigated.The principles,applications,and development status of femtosecond optical frequency comb technology,precision measurement technology for atomic ensemble and quantum light field,and quantum enhancement measurement technology based on nonlinear interference are analyzed.It could provide reference for the development of measurement technology in China. Related Articles | Metrics | Comments（0）

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Development Trend of Metrology and Measurement in the Quantization and Digitalization Revolution DU Xiao-shuang, HU Yi-fei, FENG Ying-qiang, CHEN Bei, ZENG Wu, FEI Feng, LI Wei, TU Zhi-guo, YANG Xiao-wei, ZHAI Yu-wei, HAO Xin-you Journal of Astronautic Metrology and Measurement    2023, 43 (5): 11-22.   DOI: 10.12060/j.issn.1000-7202.2023.05.02 Abstract （246）      PDF（pc） （8846KB）（147）       Knowledge map    Save Developed countries in the America and Europe attach great importance to the development of metrology and measurement technology,incorporating forward-looking and fundamental measurement technologies such as quantum and digital intelligence into their national development strategies,and seizing the technological high ground.In recent years,China has made breakthroughs in metrology research fields such as atomic frequency standards and cold atomic gravimeters,and has entered the ranks of advanced countries in international metrology.At present,with the quantization and digital transformation of international metrology,the evolution of quantization in metrology is constantly accelerating,the mode of measurement transmission is gradually transitioning towards digitization,and the trend of metrology support technology is becoming more practical.The development trend of metrology and measurement technology is given and a close analysis is made in this paper,providing a useful reference for the development of China metrology and measurement. Related Articles | Metrics | Comments（0）

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Review of Research Advance on Cold-atom Gravimeter BAI Jin-hai, MA Hui-juan, HU Dong, WANG Yu Journal of Astronautic Metrology and Measurement    2023, 43 (5): 1-10.   DOI: 10.12060/j.issn.1000-7202.2023.05.01 Abstract （197）      PDF（pc） （4579KB）（2645）       Knowledge map    Save The cold atom gravimeter uses laser cooling,atomic interference manipulation,and other technologies to achieve absolute gravity acceleration measurement.It is a new type of quantum sensor that has developed rapidly over the [JP2]past three decades.Currently,its measurement sensitivity has exceeded that of traditional laser interference absolute gravimeters,and the measurement uncertainty has reached the same level.In metrology traceability,basic scientific research,geophysics,resource exploration,autonomous navigation and other aspects have important application value.Analyzes the principle of cold atom gravimeters,introduces the research progress and development trend of cold atom gravimeters,and analyzes and combs the research direction of cold atom gravimeters,especially the key points in dynamic application scenarios. Related Articles | Metrics | Comments（0）

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Study of Development and Current Status of Quantum References for Voltage ZHANG Jinkai, JIANG Zhu, HU Jiaxin, WANG Bing Journal of Astronautic Metrology and Measurement    2024, 44 (4): 1-10.   DOI: 10.12060/j.issn.1000-7202.2024.04.01 Abstract （159）      PDF（pc） （2181KB）（244）       Knowledge map    Save Centered on a discussion of the development of voltage quantum references and their current status,the Josephson effect，the resulting principles of Josephson junctions and Josephson junction arrays are expounded.The transition from traditional Josephson voltage references to programmable Josephson voltage references as the demand for measurements expands from DC to AC are described.The development history,research results,and applications of two important electrical metrology topics,namely,programmable voltage standards are focused on,based on binary division arrays and pulsedriven arrays,which are at the forefront of current research.Finally,the development of voltage quantum reference over the years is summarized and its future development direction is envisioned. Related Articles | Metrics | Comments（0）

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Test and Analysis of Thermal Response Time of Temperature Sensor LIU Baoju, GUO Yafei, ZHANG Junqi, ZHANG Zhongjie, LV Yueyuan, LIU Lin, CHEN Yiqing Journal of Astronautic Metrology and Measurement    2024, 44 (4): 35-39.   DOI: 10.12060/j.issn.1000-7202.2024.04.06 Abstract （150）      PDF（pc） （2601KB）（100）       Knowledge map    Save Most of the domestic thermal response time tests for temperature sensors are conducted in 90 ℃ silicone oil by oil bath method,and the test method is single without considering the relationship between the actual use environment of temperature sensors and the test environment,and the test method is manual test with low efficiency and poor reproducibility.To solve this problem,an automatic test device for thermal response time of temperature sensor is designed based on Labview software.The thermal response time of PT100 platinum resistor,PT1000 platinum resistor and thermistor temperature sensor is tested,and the influence of different packaging and heating methods on the thermal response time of temperature sensor is analyzed.It is proved that different packaging methods and heating methods have great influence on the thermal response time test.The test device studied can be applied to the response time measurement of all types of temperature sensors. Related Articles | Metrics | Comments（0）

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Research on Gas Temperature Measurement Based on Dual-comb Spectroscopy Technology GAO Xiao-qiang, LIU Hao, ZHANG Zhi-tao, Wu Wei-wei Journal of Astronautic Metrology and Measurement    2023, 43 (6): 12-16.   DOI: 10.12060/j.issn.1000-7202.2023.06.03 Abstract （148）      PDF（pc） （2609KB）（326）       Knowledge map    Save As a new technology,dual-comb spectroscopy has the advantages of high resolution,high sensitivity,wide spectral coverage and high speed measurement,which has unique advantages and broad development prospects in the field of molecular precision spectral analysis.A high temperature gas measurement scheme based on dual-comb spectrum is proposed.Two combs with small refrequency difference are used to achieve high temperature gas absorption spectrum measurement with high precision through asynchronous sampling,and the spectral temperature inversion algorithm is used to obtain the gas temperature value.In the experiment,a dual-comb system with repetition rate of about 205.315 MHz and 205.365 MHz was used to achieve high precision measurement of the absorption spectrum of CO2 gas at 1 057 K at a wavelength of 4.2 μm.The results show that,as an active temperature measurement technology,it has the ability of accurate measurement of high temperature gas,and has an important application prospect in the field of high temperature measurement of national defense equipment. Related Articles | Metrics | Comments（0）

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A Review of Mid-infrared Gas Detection Technology Based on Quantum Precision Measurement ZHU Tianyi, FENG Dianying, XU Feng, DONG Yazhuo, ZHANG Wenshen, HOU Qianqian, LIU Xia, WANG Wei Journal of Astronautic Metrology and Measurement    2024, 44 (5): 16-24.   DOI: 10.12060/j.issn.1000-7202.2024.05.03 Abstract （143）      PDF（pc） （3020KB）（270）       Knowledge map    Save This article reviews mid-infrared gas detection technology based on quantum precision measurements.With the development of the semiconductor industry,the requirements for the purity of electronic process gases continue to increase.Traditional mid-infrared gas detection technology faces sensitivity and accuracy challenges in trace gas detection.This article analyzes in detail the characteristics,application status and limitations of technologies such as fiber evanescent waves,photoacoustic spectroscopy,Fourier transform infrared spectroscopy,tunable diode laser absorption spectroscopy and optical cavity ring-down spectroscopy,and focuses on the introduction of quantum correlation spectroscopy.Mid-infrared gas detection technology breaks through the performance bottleneck of traditional mid-infrared detectors by utilizing photon quantum detectors and frequency up-conversion technology,significantly improving detection sensitivity and signal-to-noise ratio.This technology will become a key research direction in the future and This technological breakthrough provides an important reference for achieving higher-precision trace gas detection. Related Articles | Metrics | Comments（0）

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Theoretical Background of Quantum Metrology DING Guo, GUO Sheng, ZHU Jing-hua, DENG Peng-bo Journal of Astronautic Metrology and Measurement    2023, 43 (6): 44-48.   DOI: 10.12060/j.issn.1000-7202.2023.06.08 Abstract （134）      PDF（pc） （736KB）（228）       Knowledge map    Save The history of quantum mechanics is outlined and the fundamental formulas:the Schrdinger equation with the interpretation of the wave function,the Pauli exclusion principle,and the Heisenberg uncertainty principle are presented.The latter is illustrated with sample numerical calculations using this principle.The application of quantum effects in metrology,and present and compare the limits of accuracy and resolution of classical and quantum standards are briey discussed.The role of quantum effects in the new International System of Units are discussed as well.Although quantum effects have a wide range of applications,it is difficult to be understood by the public as it is strongly theoretical,which is reflected in many shortcomings in the 2018 version of SI.Finally,development of quantum metrology are prospected. Related Articles | Metrics | Comments（0）

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Revolution of Mass Quantum Metrology and Development of Watt Balance YANG Rong-qi, WANG Si-xian, WANG Xun Journal of Astronautic Metrology and Measurement    2023, 43 (6): 7-11.   DOI: 10.12060/j.issn.1000-7202.2023.06.02 Abstract （130）      PDF（pc） （1573KB）（264）       Knowledge map    Save The evolution of the definition of kilogram,the basic unit of SI,was discussed.The specific causes that drive the rapid realization of quantization of mass unit was clarified with the corresponding impact on mass metrology and electrical metrology.The internal logic of quantization of mass unit based on Avogadro constant and Planck constant was analyzed.The specific principle of establishing a relation between macroscopic mass and Planck constant by watt balance was discussed.The development and relative standard uncertainties of the measurement of watt balance in six institutions such as NPL,NIST and NIM was introduced.The data show that China has entered the international advanced level in the field of mass quantum metrology. Related Articles | Metrics | Comments（0）

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Research on Quantum Metrology for Wideband Microwave Electric Field CHENG Yong-jie, JIN Gang, HAN Bin-bin, PENG Bo, HUANG Cheng-zu, LIU Xing-xun, QI Wan-quan Journal of Astronautic Metrology and Measurement    2023, 43 (3): 1-4.   DOI: 10.12060/j.issn.1000-7202.2023.03.01 Abstract （124）      PDF（pc） （1606KB）（181）       Knowledge map    Save As the seven basic units of the SI system have been defined by the basic physical constants, the measurement has entered the era of quantization. Relying on the stability and reproducibility of Rydberg atom, The microwave electric field measurement technology can realize high sensitivity and low uncertainty. It can be directly trace the microwave electric field to the frequency unit. We adopts AT-splitting measurement technique and superheterodyne measurement technique to realize the measurement of microwave electric field with the microwave frequency range of （1~40） GHz and the field strength range of 0.5 mV/m~10 V/m by use cesium atom vapor cell. This work will impact diverse areas like metrology, radar, terahertz communication and electromagnetic signal monitoring. Related Articles | Metrics | Comments（0）

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A Review of Progress in Miniaturization of Cold Atom Quantum Vacuum Measurement Devices CHENG Yong-jun, DONG Meng, SUN Wen-jun, WU Xiang-min, ZHANG Ya-fei Journal of Astronautic Metrology and Measurement    2023, 43 (6): 17-24.   DOI: 10.12060/j.issn.1000-7202.2023.06.04 Abstract （122）      PDF（pc） （7384KB）（317）       Knowledge map    Save Quantum vacuum measurement is an important development direction of vacuum measurement technology in the future.Based on intrinsic physical properties of matter,quantum vacuum measurement has the characteristics of no calibration,little disturbance to vacuum environment and high precision.Currently,laboratory-scale cold atom quantum vacuum measuring devices have shown excellent performance,and scientists are working hard to advance the practical application of quantum sensors,which means that cold atom quantum vacuum measuring devices must be transformed from large laboratory-scale platforms to compact miniaturization quantum sensors.This requires miniaturization quantum sensors to have both a small size and excellent performance under extreme dynamic conditions.The latest advances in cold atom quantum sensor miniaturization is presented,focusing on the key components required for atomic cooling,including laser systems,atomic sources,magneto-optical traps,and coils.The miniaturization scheme of each element and its influence on the sensor performance is discussed,and the development of cold atom quantum vacuum sensor is prospected. Related Articles | Metrics | Comments（0）

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Remote Sensing Image Classification Based on Deep Convolution Transfer Learning Network Algorithm WANG Xiaozhuo, WANG Kai, CAO Shu Journal of Astronautic Metrology and Measurement    2024, 44 (4): 97-102.   DOI: 10.12060/j.issn.1000-7202.2024.04.17 Abstract （122）      PDF（pc） （787KB）（131）       Knowledge map    Save Due to the lack of resampling processing for graphic features,the final classification accuracy and the classification performance are not ideal.To this end,a remote sensing image classification based on deep convolution transfer learning network algorithm is proposed.By dividing the geometric region of the original remote sensing image,extracting the descriptors for the distorted geometric pixel,combining the scale space and pixel registration and the rotation angle of the image is calculated,and the geometric correction of the remote sensing image is completed.The dual stream network architecture is innovatively adopted to splice the channel of pixel frequency bands,combining the interaction results of image consistency joint features,outputting image fusion features,and resampling the features with new pixel value index.The deep convolutional transfer learning network algorithm is used to calculate the probability of the input image in the reference class,so as to realize the remote sensing image classification.The application results of the example show that the designed method has high classification accuracy and better classification performance in remote sensing image classification. Related Articles | Metrics | Comments（0）

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Research on Measurement Method for Spectral Emissivity and Hemispherical Emissivity of Infrared Materials WANG Ruiqin, HAN Ying, GAO Yuan Journal of Astronautic Metrology and Measurement    2024, 44 (4): 40-43.   DOI: 10.12060/j.issn.1000-7202.2024.04.07 Abstract （121）      PDF（pc） （1933KB）（108）       Knowledge map    Save In response to the demand for accurate measurement of surface emissivity of infrared materials,the directional spectral emissivity and hemispherical total emissivity of the sample materials were measured using a spectral equipment with integrating sphere attachment and a emissometer at room temperature in the laboratory,and the results were converted.Through the study of the two measurement methods,it is shown that the spectral emissivity of infrared materials is consistent with the hemispherical total emissivity,which verifies the effectiveness of the two measurement methods and provides a reference for the measurement of surface emissivity parameters of infrared materials. Related Articles | Metrics | Comments（0）

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Progress and Prospect of Artificial Intelligence Application in Metrology GONG Kenan, HU Bo, XU Xuan, HUANG Yifan, CHENG Fang Journal of Astronautic Metrology and Measurement    2024, 44 (6): 28-41.   DOI: 10.12060/j.issn.1000-7202.2024.06.04 Abstract （120）      PDF（pc） （1136KB）（47）       Knowledge map    Save Artificial Intelligence (AI) technologies are increasingly applied in metrology,bringing new vitality to traditional measurement methods.The applications and development trends of AI in metrology is systematically reviewed from micro,meso and macro levels.At the micro level,the innovative applications of AI in optical measurement,mechanical measurement,quantum metrology,and automated calibration，is analyzed.At the meso level,the integration of intelligent sensor networks,edge AI,and blockchain technologies are discussed.At the macro level,the practical applications of AI in environmental monitoring and industrial manufacturing is summarized.Based on literature analysis,it is found that AI metrology research has shown rapid growth over the past decade,with a significant increase in research intensity after 2018.Focusing on key issues such as standardization,uncertainty quantification,and model interpretability,current challenges and prospects for future research directions are explored. Related Articles | Metrics | Comments（0）

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A Method to Extend Range of GMSK Spread Spectrum Doppler Acquisition LIAO Xiaohai, OU Jiacheng, ZHOU Bin, WANG Hui, XU Yang Journal of Astronautic Metrology and Measurement    2024, 44 (2): 31-38.   DOI: 10.12060/j.issn.1000-7202.2024.02.06 Abstract （118）      PDF（pc） （2324KB）（152）       Knowledge map    Save Pseudo-code acquisition is an indispensable and important part in short-time burst GMSK spread spectrum communication.Especially in the case of weak signal at the receiving end,Doppler frequency shift will seriously affect the performance of pseudo-code acquisition at the receiving end.Aiming at the particularity of short-time burst GMSK spread spectrum system,a pseudo-code acquisition algorithm at the receiving end is designed,and the relevant formulas of the acquisition algorithm are deduced and analyzed.On this basis,a multi-channel parallel receiving acquisition method is proposed to adapt to the short-time burst condition.This method improves the pseudo-code acquisition performance of the GMSK spread spectrum communication system by expanding the Doppler adaptation range.Applying this method to the short-time burst GMSK spread spectrum communication system can increase the pseudo-code acquisition peak threshold by about 2.7 dB to meet the system sensitivity requirements,and occupy less hardware resources. Related Articles | Metrics | Comments（0）

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Recent Progress and Applications on Fiber-based Optical Frequency Comb LI Haonan, CHEN Xinyi, YANG Honglei, GE Jun Journal of Astronautic Metrology and Measurement    2024, 44 (3): 1-10.   DOI: 10.12060/j.issn.1000-7202.2024.03.01 Abstract （117）      PDF（pc） （2545KB）（297）       Knowledge map    Save Invented at the turn of the century,Optical frequency comb has coherently bridged between radio frequencies and optical frequencies.With more than 20-years continuous development,optical frequency comb has revolutionized optical frequency measurement methods and been widely used in precision measurement beyond that.Firstly,the advantages of the fiber optical frequency comb are highlighted,and the technical principle of the fiber optical frequency comb is briefly introduced.Then,the main development directions of the fiber optical frequency comb,namely low noise,high power,and integration,are analyzed.Finally,the application progress of the fiber optical frequency comb in optical frequency measurement,absolute distance measurement,ultra-low noise microwave generation,precise spectral measurement,and astronomical spectral calibration are discussed. Related Articles | Metrics | Comments（0）

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Application of Heat Treatment Furnace Temperature Field Detection in Equipment Repair Process ZHENG Zhiqing, DUAN Wenling, AN Jun, LAI Lu, PANG Li, CHEN Yingnan Journal of Astronautic Metrology and Measurement    2024, 44 (2): 60-63.   DOI: 10.12060/j.issn.1000-7202.2024.02.10 Abstract （115）      PDF（pc） （677KB）（111）       Knowledge map    Save The importance of heat treatment process to equipment repair is determined by analyzing the role and influence of various types of heat treatment furnaces on metal materials or parts in the process of aircraft equipment repair.The influence of furnace temperature uniformity on product heat treatment results is briefly described,and the treatment methods of non-conformity of test results are encountered in the process of heat treatment furnace temperature uniformity test.Through technical means to ensure the conformity of heat treatment furnace temperature uniformity test results in the effective heating area,improve the heat treatment quality of equipment repair products,and ensure the repair cycle and repair quality of equipment. Related Articles | Metrics | Comments（0）

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Precision Measurement and Application of Quantum Interference Based on Compressed Light and Entangled Light ZHANG Yong-chao, ZHANG Tie-li, GAO Xiao-qiang, LIU Xiao-xu, XU Yong-yao Journal of Astronautic Metrology and Measurement    2023, 43 (6): 25-30.   DOI: 10.12060/j.issn.1000-7202.2023.06.05 Abstract （112）      PDF（pc） （3194KB）（443）       Knowledge map    Save Quantum precision measurement technology has shown broad application prospects in many fields due to its advantage of breaking through the standard quantum limit (SQL).The basic principles of quantum interferometry based on compressed and entangled light were introduced,mainly including the principles of Hong Ou Mandel (HOM) interferometry and Mach Zehnder (MZ) interferometry.This article summarizes the main application directions of quantum interferometry technology at present,including applications in the simultaneous measurement of small displacement and angle multiple parameters,gravitational wave measurement,gas concentration detection,and quantum imaging.It looks forward to the future development and application prospects of quantum precision measurement technology,and analyzes the current problems and future development trends. Related Articles | Metrics | Comments（0）

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Research Progress of High-precision Autonomous Navigation Based on Cold Atom XIE Hong-tai, KANG Ze-hao, HU Dong, WANG Yu Journal of Astronautic Metrology and Measurement    2023, 43 (6): 31-38.   DOI: 10.12060/j.issn.1000-7202.2023.06.06 Abstract （108）      PDF（pc） （3238KB）（434）       Knowledge map    Save All-weather,high anti-interference,and high concealment positioning,navigation and timing without exchanging information with the outside world can be achieved by autonomous navigation.Cold atom interferometry is with ultra-high sensitivity and stability due to its characteristics of matter wave and absolute measurement,and is expected to create an autonomous high-precision navigation system integrating inertial navigation,gravity and gravity gradient map matching aided navigation,and applied to long-term voyage carriers.Based on the configuration of atom interferometry,the research on cold atom sensors in recent decades over the world is summarized,and the technical schemes is analyzed,so as the selection of schemes suitable for the autonomous navigation is provided. Related Articles | Metrics | Comments（0）

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Research on Measurement Method of Milli Tesla Class Magnetic Field Based on Coherent Population Trapping ZHANG Fan, WANG Dongping, YI Siyue, CHENG Zhiyong, XIE Yin, PEI Huagang Journal of Astronautic Metrology and Measurement    2024, 44 (2): 98-102.   DOI: 10.12060/j.issn.1000-7202.2024.02.17 Abstract （107）      PDF（pc） （1193KB）（219）       Knowledge map    Save A method to measure milli tesla class magnetic field by coherent population trapping effect is proposed.Using linearly polarized laser to interact with 87Rb atoms,two divided CPT resonance signals caused by the nucleus spins in the magnetic field is obtained,and the magnetic induction strength of the magnetic field is derived by analyzing the splitting distance between the two CPT resonance signals.This method can eliminate nonlinear error caused by the high-order term to improve the accuracy of measuring the milli tesla class magnetic field and provides a new scheme for the quantum standard of milli tesla magnetic field. Related Articles | Metrics | Comments（0）

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Faraday Lasers for Quantum Metrology Applications ZHANG Jia, SHI Hangbo, WANG Zhiyang, QIN Xiaomin, LIU Zijie, GUAN Xiaolei, GAO Xun, WANG Yu, SHI Tiantian, CHEN Jingbiao Journal of Astronautic Metrology and Measurement    2024, 44 (5): 1-7.   DOI: 10.12060/j.issn.1000-7202.2024.05.01 Abstract （105）      PDF（pc） （1823KB）（252）       Knowledge map    Save High-precision frequency-stabilized lasers are an important foundation and component for realizing the realization of quantum precision measurement.Faraday laser utilizes atomic filter for frequency selection,and the output wavelength is limited to the transmission spectrum near the atomic transition frequency,which has significant advantages such as automatic correspondence between wavelength and atomic spectral line,narrow linewidth,and resistance to laser diode current and temperature fluctuations.Faraday lasers have many applications in the field of quantum metrology,such as atomic clocks,atomic gravimeters,and atomic magnetometers.Starting from the research background and basic principle of Faraday lasers,we introduce the practical applications and important values of Faraday lasers in such fields as cesium atomic clock,atomic gravimeter,and optical communication are introduced.In the future,with the continuous maturity and innovation,Faraday lasers are expected to realize a wide range of applications in more fields,such as high-power laser weapons,Reedburg atomic radar,etc.,which are expected to play a greater role in the field of national defense and military industry measurement. Related Articles | Metrics | Comments（0）

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The Study on the Measurement of the Ambient Dose Equivalent of Gamma Radiation in n,γ Mixed Radiation Fields Using a G-M Counter WANG Yuchen, XU Xinyu, LI Chunjuan, LIU Yina, WANG Zhiqiang, DUAN Junyi, LUO Hailong Journal of Astronautic Metrology and Measurement    2024, 44 (5): 86-91.   DOI: 10.12060/j.issn.1000-7202.2024.05.14 Abstract （104）      PDF（pc） （1834KB）（82）       Knowledge map    Save Based on the mechanisms of neutron production and reactions,neutron reference radiation fields are n,γ mixed fields,where the gamma component primarily originates from gamma rays accompanying neutron production and those generated by the interaction of neutrons with materials in the radiation field environment.This paper investigates the application of an energy-compensated Geiger-Müller(G-M) counter in n,γ mixed radiation fields.Using the Monte Carlo (MC) particle transport code MCNP,the energy response of the G-M counter was simulated,and experimental validation was conducted in a gamma reference radiation field.The validation demonstrated that the energy compensation scheme effectively suppresses the over-response in the low-energy region.Utilizing this energy-compensated G-M counter,the ambient dose equivalent of gamma radiation in laboratory radioactive nuclide neutron source fields was measured.This improves the parameters of the reference radiation field and provides support for addressing calibration issues arising from the gamma response characteristics of neutron instruments. Related Articles | Metrics | Comments（0）

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Discussion on Construction of Aerospace Model Metrologist System FENG Zhi-jun, MIAO Chun-lin, LIU Dan-ning, DU Jun-peng, ZHOU Kai, LIU Kai Journal of Astronautic Metrology and Measurement    2023, 43 (4): 86-89.   DOI: 10.12060/j.issn.1000-7202.2023.04.14 Abstract （102）      PDF（pc） （672KB）（174）       Knowledge map    Save Aerospace model engineering is a large-scale，comprehensive and complex system engineering，as the technical basis of model development，the level and efficiency of model development is improved by metrology.Combined with the content of metrology in the aerospace model development workflow,the necessity of model metrologist system construction is analyzed,the idea of building the model metrologist system is put forward，the specific composition and main responsibilities of the model metrologist system is studied，the significance of establishing a model metrologist system is analyzed.The construction method of the aerospace model metrologist system will be referenced for all military industries. Related Articles | Metrics | Comments（0）

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Method for Analyzing Uncertainty of High Precision Ultrasonic Flowmeter for Main Feedwater LIU Yan, WEI Hua-tong, BAI Tian, WANG Feng-ning, REN Da-cheng, LIU Li, CUI Xi-wei, GUO Lin Journal of Astronautic Metrology and Measurement    2023, 43 (4): 1-7.   DOI: 10.12060/j.issn.1000-7202.2023.04.01 Abstract （101）      PDF（pc） （994KB）（330）       Knowledge map    Save The methodology of high-precision measurement of main feedwater flow is proposed based on Hualong No.1 and other nuclear power plants(NPP) to achieve measurement uncertainty recapture power uprates(MUR).The components of uncertainty measured by ultrasonic flowmeter such as calibration coefficient and medium density are quantified.Under the conditions with defining the structure and measurement principle of ultrasonic flowmeter and the complex operating conditions of high pressure and high temperature(HPHT),the uncertainty evaluation methodology of channel geometric factor and pipe cross-sectional area has been given respectively.By analyzing the influence of the operating conditions on the flow measurement,the uncertainty introduced by the flow field velocity has been evaluated.The analysis results indicate that the metrological traceability method which based on the combination of several uncertainty evaluation methods is feasible. Related Articles | Metrics | Comments（0）

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Development Trend of High Performance Passive CPT Atomic Clock  DING Chen-feng, CHEN Hai-jun Journal of Astronautic Metrology and Measurement    2023, 43 (5): 23-30.   DOI: 10.12060/j.issn.1000-7202.2023.05.03 Abstract （98）      PDF（pc） （1126KB）（364）       Knowledge map    Save The use of a single circularly polarized light configuration to achieve a CPT state will generate a polarized dark state,resulting in a lower contrast of the CPT signal.Therefore,the frequency stability index of traditional CPT atomic clocks is not high.In order to improve the contrast of CPT signals and improve the performance of CPT atomic clocks,various schemes for eliminating polarized dark states have been proposed and studied.These schemes can be divided into parallel line polarized light configurations and phase delayed configurations based on the polarization state and generation method of the laser used σ+-σ- Configuration,push-pull pump configuration,vertically polarized light configuration,polarization modulation configuration.Based on the principles and development level of these schemes,a comparative analysis of their advantages,disadvantages,and improvement plans can be conducted to explore new development directions for high-performance atomic clocks under different demand conditions. Related Articles | Metrics | Comments（0）

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Research Progress on the Mercury Ion Trapped Microwave Clock WANG Nuan-rang, YI Hang, XUE Xiao-bo, ZHANG Sheng-kang Journal of Astronautic Metrology and Measurement    2023, 43 (5): 31-35.   DOI: 10.12060/j.issn.1000-7202.2023.05.04 Abstract （98）      PDF（pc） （4478KB）（236）       Knowledge map    Save The mercury ion trapped microwave clock utilizes a quadrupole trap to achieve ion trapping,and completes the preparation of mercury ion states through a mercury lamp,making it easy to integrate and miniaturize.Through the optimization and design of key components such as ion trap,mercury lamp and its optical path,the pump light emitted by the mercury lamp can fully interact with the ions trapped in the ion trap to complete the preparation of states.40.5 GHz microwave is transmitted to the center of the ion trap through the horn antenna to complete the inversion of the ion number.The transiting line of the trapped mercury ions is detected by a weak fluorescence detection system and the measured transiting line width is about 1 Hz.The closed-loop locking of mercury ion microwave clock is achieved by the servo loop control system.After experiment testing,the frequency stability index can reach 4E-13/τ(1 s≤τ≤1 000 s) and 7E-15 at 10 000 s. Related Articles | Metrics | Comments（0）

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Development Status and Metrology Prospect of Terahertz Quantum Correlation Imaging and Quantum Dot Detector LI Hong-guang, WANG Yuan-bo, LIAO Wen-tao Journal of Astronautic Metrology and Measurement    2023, 43 (5): 41-46.   DOI: 10.12060/j.issn.1000-7202.2023.05.06 Abstract （96）      PDF（pc） （2451KB）（650）       Knowledge map    Save The cross research between quantum technology and cutting-edge disciplines such as terahertz technology has led to the emergence of disruptive new system devices such as terahertz quantum correlation cameras and quantum dot detectors,expanding the space for new quality and new domain defense applications.Compared to traditional imaging technology,terahertz quantum correlation imaging based on quantum technology exhibits unique advantages in imaging speed,imaging resolution,and other aspects.The terahertz quantum correlation imaging system is based on terahertz emission sources,detection systems,masks,algorithms,etc.,achieving compression sensing,time resolution,Fourier transform,and other imaging technologies.In addition,a review was conducted on terahertz quantum correlation imaging systems and quantum dot detectors,and corresponding research on terahertz quantum correlation imaging and measurement calibration technology of terahertz quantum dot detectors was explored.By proposing metrological problems and solutions,which provides the application prospects of terahertz quantum detection and imaging metrology technology. Related Articles | Metrics | Comments（0）

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An 852 nm Frequency-stabilized Laser Based on the Ultrastable Cavity PDH Locking Technique#br# MA Jiyang, SHEN Tong, XUE Xiaobo, ZHAO Weinan, SU Yabei, YANG Honglei, ZUO Yani, ZHANG Shengkang Journal of Astronautic Metrology and Measurement    2024, 44 (3): 68-74.   DOI: 10.12060/j.issn.1000-7202.2024.03.11 Abstract （95）      PDF（pc） （2399KB）（246）       Knowledge map    Save Since the development of laser locking technology in the 1980s,ultrastable lasers have played an important role in high-precision optical quantum time-frequency metrology,such as optical clocks,gravitational wave detection,cavity quantum electrodynamics,and satellite-ground communication.The Pound-Drever-Hall(PDH) technology provides a good way to stabilize free running lasers.Here,by utilizing such method,we lock the 852 nm wavelength laser to the resonance frequency of the ultrastable cavity to achieve the highly-stabilized laser output.In the experiment,the quality factor of the ultrastable resonator reached 1010,the finesse reached 200,000,and the 1 second frequency stability of the output laser reached 5.2×10-15 with laser linewidth of 2.3 Hz.This continuous laser with such frequency stability will provide robust technical support for an 852 nm clock laser with good correlation with Cs atoms. Related Articles | Metrics | Comments（0）

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Application of Continuous Thermocouple Temperature Measuring System in High Temperature Aging System SUN Qiang, HUANG Xianwu, JIN Ran, LI Yinchuan, FU Jie Journal of Astronautic Metrology and Measurement    2024, 44 (5): 92-96.   DOI: 10.12060/j.issn.1000-7202.2024.05.15 Abstract （94）      PDF（pc） （3486KB）（108）       Knowledge map    Save In order to realize the real-time monitoring of the temperature in the effective working area of the high temperature aging system,and avoid the failure and damage of the chip or electronic component caused by abnormal temperature,according to the principle that the output thermoelectric potential of the continuous thermocouple is always corresponding to the highest temperature in the temperature sensing section,a set of real-time temperature measurement system using the continuous thermocouple as the temperature sensing element is built.The system is simple in layout and low in cost.The real-time temperature measurement system is used to verify the test data of the constant state and the temperature gradient state respectively,and the expected effect can be achieved.The system can effectively monitor the aging system working area temperature,achieve centralized monitoring,and according to the chip or electronic components aging temperature,be free to set early warning and alarm temperature points. Related Articles | Metrics | Comments（0）

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The Research Advancements and Trends in Chip-integrated Metrology within the Framework of the New International System of Units (SI) GUO Linbao, ZHAO Zhao, LI Daozheng, LI Yajie, SHA Changtao, ZHANG Hong Journal of Astronautic Metrology and Measurement    2024, 44 (5): 8-15.   DOI: 10.12060/j.issn.1000-7202.2024.05.02 Abstract （94）      PDF（pc） （2782KB）（186）       Knowledge map    Save Chip-integrated metrology serves as an implementation method,possessing the advantages of high efficiency and low cost.The significant revolution of the International System of Units (SI) has freed metrological work from the trouble of physical benchmark and made the methods of reproducing values more flexible.Along with the development of quantum measurement methods,a number of chip-scale metrological standard device have been born.Micro-Electro-Mechanical System (MEMS),microfluidics,and chip-integrated laser are key supporting technologies for chip-integrated metrology.Based on quantum measurement technology,the realization of some fundamental units in the SI,like time,length,temperature,and current,has already taken the shape of chipization.Overall,chip-integrated metrology is still in its infancy,mainly in the form of chip-based sensing elements.In the future,continuous efforts should be made to develop chip-integrated metrological standards instruments and gradually construct a chip-integrated traceability chain to fulfill chip-integrated metrology. Related Articles | Metrics | Comments（0）

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Design of Built-in Conversion Circuit of Piezoelectric Shock Sensor FANG Yuan-yong, ZHANG Jian, WU Jian, YANG Ke-xin Journal of Astronautic Metrology and Measurement    2023, 43 (6): 63-70.   DOI: 10.12060/j.issn.1000-7202.2023.06.12 Abstract （94）      PDF（pc） （1183KB）（173）       Knowledge map    Save The charge type output is used in most of piezoelectric shock sensors,and there are few piezoelectric shock sensors with built-in conversion circuit.The main reason of adopting charge output for piezoelectric shock sensors is the poor adaptability of built-in conversion circuits.Limited by the internal structure,it is difficult to make the built-in circuit meet the measurement requirements of shock tests.In order to design a built-in conversion circuit that can be used for shock sensors,the analysis of the characteristics of the shock signal and the two built-in conversion circuits of the piezoelectric sensors are analyzed,and the conclusion that the voltage conversion circuit is suitable for the built-in conversion circuit of the sensors is drawn through the analysis of the characteristics of the charge conversion and voltage conversion circuits.The built-in voltage conversion circuit sensor has been tested and verified. Related Articles | Metrics | Comments（0）

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Research on Integration and Test about Soliton Optical Frequency Comb on Chip LIU Hao, GAO Xiao-qiang, DUAN Shuo, WU Chen Journal of Astronautic Metrology and Measurement    2023, 43 (6): 39-43.   DOI: 10.12060/j.issn.1000-7202.2023.06.07 Abstract （92）      PDF（pc） （7899KB）（139）       Knowledge map    Save The optical frequency comb is composed of a series of coherent lasers distributed at equal intervals.As a high-precision frequency standard,it can realize ultra-fine scanning of the gas absorption spectrum,and has important applications in the fields of spectral analysis and combustion diagnosis.Micro-ring resonator optical frequency combs based on the Kerr nonlinear effect are expected to become a new generation of integrated light sources due to their advantages of small size,light weight,and low power consumption.The on-chip soliton optical frequency comb integration and testing research is carried out,the integrated packaging of the soliton optical frequency comb is realized,the evolution process of the soliton is observed experimentally,and the wavelength range of the broadband soliton optical frequency comb is greater than 100 nm,and the repetition frequency is greater than 49 GHz.Meanwhile,a dual-comb system was constructed based on the double micro-ring resonator,with a repetition frequency difference of 14.69 MHz,which realized the fine scanning of the C2H2 absorption spectrum. Related Articles | Metrics | Comments（0）

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Rapid Detection of SAR Images of Naval Vessels Based on Improved YOLOv5-ResNet LONG Hao, ZHANG Sijia, ZHOU Jing, WANG Guan Journal of Astronautic Metrology and Measurement    2024, 44 (2): 52-59.   DOI: 10.12060/j.issn.1000-7202.2024.02.09 Abstract （90）      PDF（pc） （4074KB）（135）       Knowledge map    Save Under the influence of natural factors such as bad weather and waves,it is often difficult to effectively carry out ship target monitoring based on visible light data and other means,which requires the use of active microwave imaging satellite synthetic-aperture radar (SAR) for image interpretation.To address the issue of inaccurate feature extraction by deep learning when dealing with small datasets and images,as well as the problem of high data similarity,a cross-scale fusion mechanism based on YOLOv5-ResNet is proposed to redefine the loss function.The research shows that there is a certain improvement in the accuracy of identifying SAR ship targets:the maximum accuracy of identifying single ships is 93%,which is 4% higher than YOLOv5 and 20% higher than YOLOv5-ResNet50.In near-shore ship target detection,it effectively reduces the unnecessary increase in error rate caused by poor data set quality and inappropriate model training methods. Related Articles | Metrics | Comments（0）

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Simulation of Heat Transfer Process in an OCXO under Extreme Environment LI Jikang, PENG Huili, YU Dejiang, ZHENG Zhenrong Journal of Astronautic Metrology and Measurement    2024, 44 (1): 76-82.   DOI: 10.12060/j.issn.1000-7202.2024.01.13 Abstract （87）      PDF（pc） （2921KB）（91）       Knowledge map    Save The crystal is the core component of the oven-controlled crystal oscillator,which needs to keep the temperature constant,and the great change of the external ambient temperature will surely affect the stability of the output frequency signal of the crystal.According to the working state and mechanism of the OCXO,a mathematical model of the heat transfer process in the steady state is established,the thermal stability of the crystal in high and low temperatures is investigated,and the influence of the output power of the power tubes on the temperature at the crystal in different ambient temperatures is emphasized,and the data during the actual operation of the OCXO are used for verification.The results show that the data obtained through simulation are basically consistent with the measured data;when the ambient temperatures are -40 ℃,25 ℃ and 70 ℃,respectively,the temperature at the stabilized crystal is 85 ℃,and the corresponding output power after stabilization of the power tubes is 3.95 W,1.42 W and 0.74 W.The output power of the power tubes is adjusted to make the temperature at the crystal constant.By adjusting the output power of the power tubes,the crystals can reach the preset temperature and keep it constant under extreme environments,so that the crystals can have high frequency stability and low phase noise level,and ensure the output of high-precision clock signals. Related Articles | Metrics | Comments（0）

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Development of High Temperature and High Pressure Ultrasonic Flowmeter and Uncertainty Evaluation GUO Weiwang, YANG Jian, LIU Hai, LIU Zhigang, WANG Qiang, CUI Xiwei, KANG Zhizeng, LIU Yan Journal of Astronautic Metrology and Measurement    2024, 44 (2): 25-30.   DOI: 10.12060/j.issn.1000-7202.2024.02.05 Abstract （86）      PDF（pc） （2242KB）（121）       Knowledge map    Save In response to the operating characteristics of high temperature（240 ℃） and high pressure (12.2 MPa) in the main feedwater of domestic nuclear power plants,a high-precision ultrasonic flowmeter was developed based on the principle of time-difference method,which can achieve small power increase in the main feedwater flow measurement. The working principle,overall structure and design parameters of various components were introduced.The design ideas of the ultrasonic flowmeter scheme are summarized，the sources of uncertainty components in ultrasonic flowmeter measurement were proposed,and evaluation methods for uncertainty components in different situations were provided through experiments. The results indicate that the uncertainty components evaluation method introduced has been validated by utilizing existing flow standard devices in China,ensuring the uncertainty index of high temperature and high pressure ultrasonic flowmeter measurement,and achieving the goal. Related Articles | Metrics | Comments（0）

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Evaluation of Measurement Uncertainty for Vibration Transducers Calibration in Fixed Temperature#br# ZHU Gang, TIAN Jun-hong, DAI Yi-lin, LIU Peng, YANG Xiao-wei Journal of Astronautic Metrology and Measurement    2023, 43 (6): 49-52.   DOI: 10.12060/j.issn.1000-7202.2023.06.09 Abstract （86）      PDF（pc） （764KB）（186）       Knowledge map    Save According to absolute vibration calibration of laser interferometry in ISO16063-34,the calibration method of vibration transducer in fixed temperature was given.A uncertainty evaluation method of vibration calibration in fixed temperature is proposed in this paper.Basing on the effect factors research,the experimental results and experience,the relative expanded uncertainties of complex sensitivity at reference condition are evaluated.This method provides the reference for uncertainty evaluation of temperature sensitivity of vibration transducers in the future,and a basis for the accuracy evaluation of vibration measurement in temperature environment. Related Articles | Metrics | Comments（0）

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Development Status of Weak Current Metrology Calibration Technique Based on Atomic Magnetic Field Detection LI Wei-peng, WEI Xiao-gang, YANG Ren-fu Journal of Astronautic Metrology and Measurement    2023, 43 (5): 36-40.   DOI: 10.12060/j.issn.1000-7202.2023.05.05 Abstract （86）      PDF（pc） （984KB）（227）       Knowledge map    Save With the rapid improvement in the sensitivity of atomic magnetometers,the application of magnetic field measurement methods based on atomic ensemble is gradually expanding.In recent years,several studies have been conducted on the use of atomic magnetometers for weak current measurements,and the results have revealed the potential of this measurement method for enhancing current stability.With the high sensitivity characteristics of an atomic magnetometer,weak changes in the current are monitored by the magnetic field generated by the current,and the current is stabilized using feedback from the magnetic field measurements.It mainly describes the basic principle of atomic magnetic field detection and the current status of its application in the field of current measurement,and analyzes the key influencing factors of current measurement using atomic magnetometers,and looks forward to the development trend of this technology. Related Articles | Metrics | Comments（0）

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Development and Uncertainty Analysis of Heat Flow Field Calibration Device ZHANG Jun-qi, LI Chen-yuan, LIU Bao-ju, ZHOU Ming-rui, WU Wei-wei, ZHAO Hua-ye, LIU Xin Journal of Astronautic Metrology and Measurement    2023, 43 (4): 8-12.   DOI: 10.12060/j.issn.1000-7202.2023.04.02 Abstract （86）      PDF（pc） （1988KB）（217）       Knowledge map    Save To meet the demand of field calibration of radiant heat flow measurement system,a heat flow field calibration device was developed based on high power semiconductor laser heat source generation technology.The composition of the heat flow calibration device and the design parameters of each component of the device is introduced.The optical analysis software is used to design the optical path of heat flow source.By analyzing each uncertainty component of the field calibration device and calculating the combined extended uncertainty,the extended uncertainty of 2.7% is realized by the device,which can meet the requirements of heat flow field calibration. Related Articles | Metrics | Comments（0）

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Intercomparison of Environmental Nuclear Radiation Measuring GAO Fei, WANG Jing-qian, DONG Lu-qi, WANG Fei-fei Journal of Astronautic Metrology and Measurement    2023, 43 (5): 68-74.   DOI: 10.12060/j.issn.1000-7202.2023.05.11 Abstract （85）      PDF（pc） （776KB）（270）       Knowledge map    Save In order to check and promote the improvement of calibration ability and the technical ability of operators,and ensure the reliability of monitoring data,the measurement and comparison work of environmental nuclear radiation monitoring instrument was carried out.The intercomparison includes environmental level dosemeters, protection level dosemeters which coverage for environmental level,and γ-ray air kerma secondary standard ionization chamber.The intercomparison parameters involve air kerma and ambient dose equivalent.The intercomparison covers a wide range of environmental nuclear radiation monitoring instruments.X-ray response,γ-rays and cosmic rays response properties of the environmental nuclear radiation monitoring instruments were studied.The En value and relative error were compared to analyze and evaluate the results.As the intercomparison results,the En values of standard ionization chambers in calibration laboratory are less than 1,and all meet requirements.Most of the environmental radiation monitoring instruments meet the requirements of S-Cs measurement.However,the X-ray response of most monitoring instruments are poor.Some monitoring instrument cannot meet the requirements that the energy response variation limit dose not exceed ±30%,so it is recommended that the instrument user should verify its energy response during the first inspection. Related Articles | Metrics | Comments（0）

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Research on Measurement Standard of Offshore Static Cone Penetrometer and Uncertainty Evaluation QIAN Fei, XU Su'an, GAO Chenhao, YAN Bingnan, MA Yikai, YAN Tian Journal of Astronautic Metrology and Measurement    2024, 44 (2): 1-8.   DOI: 10.12060/j.issn.1000-7202.2024.02.01 Abstract （83）      PDF（pc） （2157KB）（121）       Knowledge map    Save In order to solve the metrological traceability of offshore static cone penetrometer,the influence of temperature on measurement is analyzed.On this basis,the measurement standard of offshore static cone penetrometer is designed.The uncertainty of measurement results is analyzed based on checking stability of the measurement standard and repeatability of experiment.The results show that the uncertainty of pore pressure is 0.017 MPa(k=2),the uncertainty of cone resistance is 0.031~0.270 kN(k=2),and the uncertainty of sleeve friction resistance is 0.031~0.036 kN(k=2).The measurement standard meets requirements for traceability of offshore static cone penetrometer. Related Articles | Metrics | Comments（0）