Chinese Astronomy and Astrophysics最新文献_第4页

Galileo E3 Total Time Delay Calibration in NTSC Time and Frequency Comparison Galileo E3 在 NTSC 时间和频率比较中的总时延校准

Chinese Astronomy and Astrophysics Pub Date : 2024-01-01 DOI: 10.1016/j.chinastron.2024.03.001

GUO Dong , DONG Shao-wu , WU Wen-jun , WANG Wei-xiong , SONG Hui-jie , WANG Xiang

{"title":"Galileo E3 Total Time Delay Calibration in NTSC Time and Frequency Comparison","authors":"GUO Dong , DONG Shao-wu , WU Wen-jun , WANG Wei-xiong , SONG Hui-jie , WANG Xiang","doi":"10.1016/j.chinastron.2024.03.001","DOIUrl":"https://doi.org/10.1016/j.chinastron.2024.03.001","url":null,"abstract":"<div>In order to improve the reliability of the time transfer link, Bureau International des Poids et Mesures (BIPM) has offcially taken the Galileo time comparison as the backup link for UTC calculation since 2020. Therefore, Galileo calibration of receiver is a necessary work for all timekeeping labs around the world to participate in the UTC link. Taking the GPS link calibrated by Physikalisch-Technische Bundesanstalt (PTB) and the National Time Service Center (NTSC) as reference, this paper sets PT09 as reference station to calibrate and verify the Galileo E3 (E1&E5a) total delay of NT02 and NT05 receivers from NTSC. The results show that the Galileo E3 total delay of NT02 and NT05 are 74.6 ns and 46.5 ns, respectively, the calibration uncertainty is 3.5 ns, and the calibration delay is relatively stable. After calibration, GPS P3 and Galileo E3 Common View results between NT02/NT05 and calibrated receivers of other timekeeping labs are basically consistent. Taking the GPS P3 links comparison results as reference between NTP3 and receivers from other labs, the average deviation is less than 1.5 ns, which is within the calibration uncertainty range.</div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"48 1","pages":"Pages 206-221"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0275106224000018/pdfft?md5=b5760ec431f28d12ff3bf386f9d775cc&pid=1-s2.0-S0275106224000018-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140164082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Study of Solar Radiation Pressure Model in BDS-3 Precise Orbit Determination BDS-3 精确轨道测定中的太阳辐射压力模型研究

Chinese Astronomy and Astrophysics Pub Date : 2023-10-01 DOI: 10.1016/j.chinastron.2023.11.001

LI Peng-jie , ZHANG Han-wei , XIE Meng-xin , ZHAO Dong-fang

{"title":"A Study of Solar Radiation Pressure Model in BDS-3 Precise Orbit Determination","authors":"LI Peng-jie , ZHANG Han-wei , XIE Meng-xin , ZHAO Dong-fang","doi":"10.1016/j.chinastron.2023.11.001","DOIUrl":"https://doi.org/10.1016/j.chinastron.2023.11.001","url":null,"abstract":"<div>For the BDS (BeiDou Navigation Satellite System) satellites, the solar radiation pressure is the major non-gravitational perturbation the satellites suffer. Due to the influence of multiple factors, accurate modeling the solar radiation pressure acting on these satellites is difficult to accomplish. The solar radiation pressure perturbation is an essential source of error in the precise orbit determination (POD) and orbit prediction processes of the BDS satellites. As the ECOMC (Empirical CODE Orbit Model 1 and 2 Combined) model adopts the advantageous features of the ECOM1 (Empirical CODE Orbit Model 1) model and the ECOM2 (Empirical CODE Orbit Model 2) model, a greater number of parameters have been introduced into the model, leading to strong correlation between the ECOMC model parameters. In response to the deficiency of the ECOMC model, the authors collected the BDS-3 satellite precise ephemeris data that were provided by Wuhan University (WHU) from January 2019 to April 2022. And by these ephemeris data, the ECOMC model’s 13 parameters were obtained through the dynamic orbit fitting method. By conducting these time sequence diagrams analysis of the ECOMC model parameters, this thesis affords the selection strategies of the solar radiation pressure parameters of the ECOMC model for BDS-3 inclined geosynchronous orbit (IGSO) and medium earth orbit (MEO) satellite. And the rationality of the selection strategies of the solar radiation pressure parameters for the ECOMC model was verified by orbit fitting and orbit prediction experiments. The results show that using the improved ECOMC model gains the best orbit fitting effects for BDS-3 IGSO and MEO satellite, and can also enhance the accuracy of medium and long-term orbit prediction of BDS-3 IGSO and MEO satellite.</div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"47 4","pages":"Pages 894-911"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138550168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Initial Orbit Determination Based on Intelligent Optimization Algorithm 基于智能优化算法的初始轨道确定

Chinese Astronomy and Astrophysics Pub Date : 2023-10-01 DOI: 10.1016/j.chinastron.2023.11.005

LIU Xin , HOU Xi-yun , LIU Lin , GAN Qing-bo , YANG Zhi-tao

{"title":"Initial Orbit Determination Based on Intelligent Optimization Algorithm","authors":"LIU Xin , HOU Xi-yun , LIU Lin , GAN Qing-bo , YANG Zhi-tao","doi":"10.1016/j.chinastron.2023.11.005","DOIUrl":"https://doi.org/10.1016/j.chinastron.2023.11.005","url":null,"abstract":"<div>Classical methods for initial orbit determination (IOD) include Laplace method, Gauss method, and their variations. In addition to this, based on the characteristic of optical observation data nowadays, experts propose some other IOD methods, like Double-<math><mi>r</mi></math> method and admissible region method. One of the ways to determinate the orbit through double-<math><mi>r</mi></math> method is to guess distances of the target from the observer at two epochs—usually at the first and the last one. By doing so, we can solve the Lambert problem, and use its solution as the initial guess of the orbit. Furthermore, we can improve the initial guess by iterations to reduce the root mean square (RMS) of the observations. The admissible method is based on the concept of attributable (longitude, latitude, and their rates). With some conceptions, the admissible region described by the range and range rate from the observer is characterized. Using triangulation we can find the nodal point that makes the RMS minimal. In our work, we apply one intelligent optimization method—the particle swarm optimization method to the two methods, based on simulated and real data, and compare the results with that of modified Laplace method. At last, we briefly discuss the possibility of applying the double-<math><mi>r</mi></math> method to the orbit link problem.</div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"47 4","pages":"Pages 837-871"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138549858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on Thermal Expansion Characteristics Measurement of Launch Lock Mechanism for SIS Mixer’s Space Application 用于 SIS 混合器空间应用的发射锁定机构热膨胀特性测量研究

Chinese Astronomy and Astrophysics Pub Date : 2023-10-01 DOI: 10.1016/j.chinastron.2023.11.010

ZHANG Bi-cheng , LIN Zhen-hui , YAO Qi-jun

{"title":"Research on Thermal Expansion Characteristics Measurement of Launch Lock Mechanism for SIS Mixer’s Space Application","authors":"ZHANG Bi-cheng , LIN Zhen-hui , YAO Qi-jun","doi":"10.1016/j.chinastron.2023.11.010","DOIUrl":"https://doi.org/10.1016/j.chinastron.2023.11.010","url":null,"abstract":"<div>The High Sensitivity Terahertz Detection Module (HSTDM) is one of the scientific payloads of the Chinese Space Survey Telescope. The core of the HSTDM is the NbN superconducting SIS (Superconductor Insulator Superconductor) mixer, operating around 10 K. The installation structure of the SIS mixer needs to be specially designed to cope with the mechanical vibration during the launch phase and the thermal insulation requirements during the operation phase. Material thermal expansion characteristics investigation based on low-temperature LVDT (Linear Variable Differential Transformer) measurement and scratch marking measurement were carried out to confirm the validity of the thermal expansion lock mechanism design. The two methods are cross verified. The LVDT experimental measurement results show that the shrinkage rate of Teflon changes with temperature and meets the theoretical model. At the same time, we verified the LVDT results with scratch marking method. Consistently, the shrinkage rate of the material is 1.86<math><mo>%</mo></math> at 80 K, so the Teflon front-end lock mechanism of the SIS mixer can achieve effective separation after cooling down.</div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"47 4","pages":"Pages 912-928"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138550169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Morphological Decomposition of the Early-type Spiral Galaxy M81 (NGC 3031) 早期型螺旋星系 M81（NGC 3031）的形态分解

Chinese Astronomy and Astrophysics Pub Date : 2023-10-01 DOI: 10.1016/j.chinastron.2023.11.002

GONG Jun-yu , MAO Ye-wei

{"title":"Morphological Decomposition of the Early-type Spiral Galaxy M81 (NGC 3031)","authors":"GONG Jun-yu , MAO Ye-wei","doi":"10.1016/j.chinastron.2023.11.002","DOIUrl":"https://doi.org/10.1016/j.chinastron.2023.11.002","url":null,"abstract":"<div>This paper presents a morphological investigation of the early-type spiral galaxy M81 (NGC 3031) through decomposition by fitting radial profiles of surface brightness using the software GALFIT, aimed at exploring structural components of M81 and quantifying their morphology. In this work, we adopt 6 types of decompositions with different numbers of morphological components, among which the most complicated one contains 5 components such as a bulge, a disk, a pair of outer spiral arms, a pair of inner spiral arms, and a galactic nucleus. The results show that, M81 hosts a classical bulge with the Sérsic index <math><mo>∼</mo></math> 5.0; the morphology and the luminosity for the bulge are almost constant in the different decomposition types. The disk of M81 has the Sérsic index <math><mo>∼</mo></math> 1.2 but the morphology and the luminosity are found sensitive to the inclusion of the inner spiral arms in the decomposition or not. The results of this work indicate that the combination of individual substructures has a considerable impact on the morphology of the galaxy as a mixture. On the basis of the results, the usability of the different types of decomposition is suggested in this work. The three-component decomposition, i.e., bulge + disk + nucleus, is applicable to statistics of large samples of galaxies; more complicated decomposition with spiral arms taken into account is suitable for precise measurements of individual galaxies in small samples. This work is based on the single-band Spitzer-The Infrared Array Camera (IRAC) 4.5 <math><mi>μ</mi></math>m image. In the future, we will carry out multi-wavelength decomposition, for the purpose of investigating spectral energy distributions and stellar population properties for the galactic substructures, and thereby deduce their formation history and evolution processes.</div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"47 4","pages":"Pages 784-817"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138549831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reference Dynamic Models for Space Debris Orbit Prediction 用于空间碎片轨道预测的参考动态模型

Chinese Astronomy and Astrophysics Pub Date : 2023-10-01 DOI: 10.1016/j.chinastron.2023.11.003

HU Song-hua , TANG Jing-shi

引用次数: 0

Analysis of the Precision of CSST Time-domain Photometric Observation CSST 时域光度观测精度分析

Chinese Astronomy and Astrophysics Pub Date : 2023-10-01 DOI: 10.1016/j.chinastron.2023.11.009

WANG Wan-hao , LIU Hui-gen , ZHOU Ji-lin

{"title":"Analysis of the Precision of CSST Time-domain Photometric Observation","authors":"WANG Wan-hao , LIU Hui-gen , ZHOU Ji-lin","doi":"10.1016/j.chinastron.2023.11.009","DOIUrl":"https://doi.org/10.1016/j.chinastron.2023.11.009","url":null,"abstract":"<div>The Chinese Space Station Telescope (CSST) is the first space optical survey telescope of China. It will perform scientific observations and yield important scientific results, e.g. multi-color photometry to find and characterize exoplanets. The precision of time-domain photometry affected by various astrophysical and instrument noises is crucial for exoplanet detection and characterization. This paper constructs a time-domain model to simulate the stellar signal and various noises based on the main technical parameters of CSST published so far. The precision of photometry is analyzed by modeling the signal and noises for an example of the gazing mode in the i-band. We investigate and discuss the contribution of various noise sources in aperture photometry, especially the jitter noise caused by pointing jitter and pixel response inhomogeneity. The test results also provide the recommended aperture sizes for photometry. Jitter noise can be suppressed by reducing jitter amplitude, uniforming pixels, or using differential photometry with reference stars. Our simulation results have broad applications, including precision predictions for time-domain photometry, the refinement of CSST instrumental specifications, the evaluation of exoplanet detection capabilities, and improvements in data reduction progress for CSST.</div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"47 4","pages":"Pages 818-836"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138549832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research Progress of Galaxy-Galaxy Strong Lensing Observed by (Sub)millimeter Interferometer 亚）毫米干涉仪观测到的星系-星系强透镜研究进展

Chinese Astronomy and Astrophysics Pub Date : 2023-10-01 DOI: 10.1016/j.chinastron.2023.11.006

LIU Xiao-hui , CAO Xiao-yue , LI Ran

引用次数: 0

Electron Cyclotron Maser Emission in Solar Radio Bursts 太阳射电暴中的电子回旋加速器发射

Chinese Astronomy and Astrophysics Pub Date : 2023-10-01 DOI: 10.1016/j.chinastron.2023.11.008

TANG Jian-fei , WU De-jin , ZHAO Guo-qing , CHEN Ling

{"title":"Electron Cyclotron Maser Emission in Solar Radio Bursts","authors":"TANG Jian-fei , WU De-jin , ZHAO Guo-qing , CHEN Ling","doi":"10.1016/j.chinastron.2023.11.008","DOIUrl":"https://doi.org/10.1016/j.chinastron.2023.11.008","url":null,"abstract":"<div>Radio bursts are ubiquitous in the cosmic plasma. Solar radio emission mainly comes from the outer atmosphere of the sun. It is an induced radiation phenomenon generated by the interaction between energetic electrons and solar atmospheric plasma. Different dynamic spectra of solar radio bursts (SRBs) contain physical information of the plasma structure and state in the radiation source region. Therefore, the radiative mechanism of radio bursts has always been the object of research. There are two kinds of coherent radiation mechanisms related to solar radio bursts: one is the plasma radiation mechanism based on electron Langmuir frequency; the other is the electron cyclotron maser (ECM) radiation mechanism based on the electron cyclotron frequency. Although these two radiation mechanisms were proposed almost at the same time, based on the understanding of the coronal environment and the ECM mechanism at that time, the ECM radiation mechanism did encounter some difficulties in explaining SRBs. Until 1979, Wu & Lee introduced the relativistic effect and used the ECM radiation to explain the earth’s Auroral Kilometric Radiation (AKR). Since then, the ECM emission has attracted wide attention. Considering some difficulties in applying the ECM emission mechanism to SRBs, we proposed a series of modified models in recent years. Firstly, the cutoff in the energy spectrum of the power-law electrons can effectively drive the ECM instability without relying on the anisotropic distribution of electron velocity. Secondly, considering the influence of Alfvén wave perturbations which are prevalent in space and celestial plasmas, a self-consistent ECM emission mechanism excited by energetic electron beams is developed. On this basis, this paper summarizes the application of the ECM emission mechanism in traditional SRB phenomena from type I to V and microwave SRBs in recent years.</div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"47 4","pages":"Pages 722-759"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138549863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Observations of Ion Cyclotron Waves in the Upstream of Mars 火星上游的离子回旋波观测

Chinese Astronomy and Astrophysics Pub Date : 2023-10-01 DOI: 10.1016/j.chinastron.2023.11.004

LI Jia-wei , YANG Lei , WU De-jin

引用次数: 0