2013 Vol. 33, No. 1

Display Method:
Recent development and preliminary results of Chinese Meridian Project
WANG Chi, REN Liwen
2013, 33(1): 1-5. doi: 10.11728/cjss2013.01.001
Abstract(2468) PDF 662KB(2709)
The Meridian Project is a ground-based network program to monitor solar-terrestrial space environment, which consists of a chain of 15 ground-based observatories located roughly along 120°E longitude and 30°N latitude. The Meridian project started in 2008, and its construction was completed by 2011. The integration and test phase of the Meridian Project conducted in 2011 demonstrated its observation capabilities as expected. The project will be in full operation in 2012. This report gives an overview of the recent development and preliminary results of the Meridian Project since 2010.
Numerical study of EUV wave on 13 February 2009
Zhang Lei, Zheng Huinan, Liao Chijian
2013, 33(1): 6-12. doi: 10.11728/cjss2013.01.006
Abstract(2384) PDF 712KB(1440)
EUV wave is observed in the extreme ultraviolet spectrum as large-scale disturbances phenomenon, often accompanied by a coronal mass ejection. Besides, EUV wave is, when displayed in EUVI 195 Å difference image, a bright ring propagating outside with the subsequent spread of the dark zone. The disturbance can often cover the whole solar disk. The current study explores the CME-EUV wave event that occurred at 05:35UT on 13 February 2009, based on the STEREO satellite observations and the three-dimensional Magnetohydrodynamic (MHD) numerical simulation. We know this CME with 340km·s-1 front velocity and 60° angular width from the COR1/STEREO-A observations. Viewing in EUVI/STEREO-B 195Å running difference images, a bright toroidal wave front propagates outside from the active region, with dimming area following the bright wave front. The fitting velocity of EUV wave from the observation data is 247km·s-1. The numerical simulation shows that the (fast-mode) wave, with legible bright front and dimming structure, propagates in a speed of 245km·s-1. The simulation results turn out to be consistent with the satellite observations and confirm that EUV wave is a fast-mode MHD wave.
Correlation research between the sunspot numbers and the cosmic rays based on wavelet and cross wavelet analysis
Weng Libin, Fang Hanxian, Zhang Yang, Yang Shenggao, Wang Sicheng
2013, 33(1): 13-19. doi: 10.11728/cjss2013.01.013
Abstract(2848) PDF 625KB(1454)
The wave and cross-wavelet methods were used to analyze the periods of sunspot number and the month-averaged cosmic ray observed by Huancayo and Climax stations, and the correlation between sunspot number and the cosmic ray was discussed. As a result, spectral analysis indicates that except for the pronounced periodicities of 11 years observed both in solar sunspot and cosmic ray intensity, 1~6 months periodicities during the high solar activity, meanwhile, 6~8 and 1~22 months periodicities in the solar cycle 22 have been detected. Cross-wavelet shows a negative correlation between the solar sunspot and the cosmic ray, and the cosmic ray intensity lag the solar activity for about 8 months. The cosmic ray intensity in Climax was predicted by the sunspot number, and the relative error decreased from 3.8912% to 3.2386%. These methods can be used to study the period and relationship of other space parameters, and to make better performance on the predicting.
Quantitative prediction of relativistic electron flux at geosynchronous orbit with geomagnetic pulsations parameters
He Tian, Liu Siqing, Shen Hua, Gong Jiancun
2013, 33(1): 20-27. doi: 10.11728/cjss2013.01.020
Abstract(2285) PDF 551KB(968)
Ultra-Low Frequency (ULF) waves can accelerate the seed electrons produced with substorm injection, which is one of the main mechanisms for relativistic electron in the magnetosphere. Based on the previous studies, the Pi1 pulsation's duration is a good indicator for seed electrons. The Pc5 pulsation's duration and spectra power are good indicators for the efficiency of acceleration. In this paper, geomagnetic field data observed by Memambetsu observatory are used to extract Pi1 pulsations. The geomagnetic field data observed by GOES-12 satellite and SODANKYLA observatory are used to extract Pc5 pulsations. With these geomagnetic pulsation parameters, a prediction model for relativistic electron flux at geosynchronous orbit is established to provide the value of a day in advance. There are two steps. First, referencing the linear prediction filter, a multi-parameter nonlinear function has been built to give a preliminary prediction value for relativistic electron flux at GEO orbit. Then, a Kalman filter is used to correct this preliminary value with the history relativistic electron flux. The data during 2004 is used to train this model. The prediction efficiency of this year is 0.73 and the linear correlation coefficient is 0.85. In the test with data during 2005-2006, the prediction efficiency is 0.69 and the linear correlation coefficient is 0.83, which is a large promotion compared with Persistence model and closed to the imitation REFM model. On one hand, the results show that the ULF wave acceleration mechanism is one of the main mechanisms for relativistic electron. On the other hand, the magnetic pulsation parameters can be well instead of the solar wind speed parameter, which would help to establish a new relativistic electron flux prediction model with ground stations.
Characteristic analysis of ionosphere TEC at Wuhan station during 23rd solar cycle
Xu Zhenzhong, Wang Weimin, Zhang Ren, Yang Shenggao, Zhou Nan, Wang Sicheng
2013, 33(1): 28-33. doi: 10.11728/cjss2013.01.028
Abstract(2451) PDF 608KB(1431)
By using Total Electron Content (TEC) at Wuhan station (30.5°N, 114.4°E), sunspot numbers and geomagnetic index from 1997 to 2007, some typical characters such as diurnal variation, seasonal variation, and semiannual variation, correlation with solar activity were analyzed. A case study was made on the responses and possible mechanism of ionosphere TEC to the magnetic storm during 13-17 April 2006. Analysis results show that diurnal variation exists constantly in high and low solar activity. Some features like semiannual anomaly and winter anomaly in TEC had been reported, but changed with solar activity. The correlation coefficient for yearly sunspot number with TEC is 0.9611. TEC correlates with the geomagnetic AE well. The response of TEC to geomagnetic storm may be caused by penetrating electric fields and neutral winds, and the specific mechanism needed to be analyzed in the future.
Equatorial ionosphere Rayleigh-Taylor instability in the presence of double-ion species
Li Caiyun, Huang Wengeng
2013, 33(1): 34-38. doi: 10.11728/cjss2013.01.034
Abstract(2407) PDF 380KB(1045)
Plasma Rayleigh-Taylor instability plays a crucial role in the development of irregularities in the nocturnal equatorial ionosphere. In traditional theories, only the dominant element O+ is taken into consideration. As a result, the liner equation is independent with the ion mass and density. In fact, in some cases, there are not only one kind of positive ion in the F region of the ionosphere, such as in dusty plasma or in the ionospheric disturbances resulting from artificially chemical releases. It is essential to understand the effect of molecular ions in the collisional Rayleigh-Taylor instability. In this paper, a linear perturbation analysis associated with continuity equations, momentum equations and current conservation equation has been used to obtain a growth rate expression in the presence of double-ion species. The new expression reveals that the growth rate is dependent with the number densities and masses of both the ion elements, and especially, the proportions of the two kinds of ions contribute to growth rate.
Relationship between severe geomagnetic storm, energetic particle storms and thermosphere density strong disturbances
Qin Guotai
2013, 33(1): 39-47. doi: 10.11728/cjss2013.01.039
Abstract(2602) PDF 1004KB(1106)
During severe geomagnetic storms, there are strong changes of high energy proton flux and high energy electron flux measured by high energy particle detectors in the geosynchronous orbit. Thermosphere density will follow strong changes in the LEO orbit. Generally, the thermosphere density increased by the enhancement of the solar F10.7 flux and the energy particle flux, however, which energy particles (e.g. proton or electron) and which particle energies (e.g. E>2MeV relativistic electrons or E<50keV low energies electrons) plays an important role during severe geomagnetic storms. This paper discussed the relationship between severe geomagnetic storm, energy particle storm and thermosphere density from the in-situ measurement data of energy particles from GOES8, GOES11 and GOES12 high energy particle detectors (from 1997 to 2007), and the thermosphere density data from Chinese satellite-borne density detectors (in 2005). The relevant results reveal that during severe geomagnetic storms, high energy proton flux of E>1MeV showed strong enhancement, with the change ratio ≥103. After one day the thermosphere density strong enhancement follow the variations of the high energy proton flux of E>1MeV and between severe geomagnetic activity, high energy proton flux and thermosphere density exhibits an obvious positive correlation, that is before the severe geomagnetic storm (near 1day), the high energy proton flux showed strong enhancement in the geosynchronous orbit, and after the severe geomagnetic storm (delay 3~6h), the thermosphere density obviously increases.
Study of sodium layer density over Haikou by Lidar during the night of 4 May 2010
Zhang Tiemin, Wang Jihong, Fu Jun, Guan Sai, Zhang Fuheng, Shen Zhenjiang, Yang Guotao
2013, 33(1): 48-52. doi: 10.11728/cjss2013.01.048
Abstract(2165) PDF 417KB(1171)
The basic characters of the sodium layer density at a low-latitude location (Haikou, China, 20°N, 110°E) are described from analysis of sodium lidar observation data. A Nd:YAG laser pumped dye laser is used to generate the probing beam. The wavelength of the dye laser is set to 589nm by a sodium fluorescence cell. The energy and divergence of the beam are about 42mJ and 1mrad, respectively. The repetition rate of Nd:YAG laser is 30Hz. The backscattered fluorescence photons from the sodium layer are collected by a telescope with a 1000mm diameter primary mirror. A sodium layer density profile of upper atmosphere is derived from lidar files collected during the night of 4 May 2010 in Haikou, China. In this paper, the relative density and the absolute one for the sodium layer profile are studied. This result, shows a good correlation with that reported by Beatty at Arecibo, Puerto Rico (18°N, 67°W). A sporadic sodium layer is observed and lasted 12 minutes.
Directional filtering due to mesospheric wind shear on the propagation of acoustic-gravity waves
Yu Yonghui, Chen Wei, Wang Yachong
2013, 33(1): 53-62. doi: 10.11728/cjss2013.01.053
Abstract(1958) PDF 728KB(1302)
Gravity waves with periods close to the Brunt-Väisälä period of the upper troposphere are often observed at mesopause altitudes as short period, quasi-monochromatic waves. The assumption that these short period waves originate in the troposphere may be problematic because their upward propagation to the mesosphere and lower thermosphere region could be significantly impeded due to an extended region of strong evanescence above the stratopause. To reconcile this apparent paradox, an alternative explanation is proposed in this paper. The inclusion of mean winds and their vertical shears is sufficient to allow certain short period waves to remain internal above the stratopause and to propagate efficiently to higher altitudes. A time-dependent numerical model is used to demonstrate the feasibility of this and to determine the circumstances under which the mesospheric wind shears play a role in the removal and directional filtering of short period gravity waves. Finally this paper concludes that the combination of the height-dependent mean winds and the mean temperature structure probably explains the existence of short period, quasi-monochromatic structures observed in airglow images of mesopause region.
Research on dynamic slots allocation supporting multi-missions for space station
Hu Shengbo, Meng Xin, Bian Chunjiang
2013, 33(1): 63-71. doi: 10.11728/cjss2013.01.063
Abstract(1886) PDF 660KB(1032)
To utilize the limited channel resources of space with efficiency and flexibility, and to improve the dynamics of space station operation, it is important to dynamically allocate slot with Quality-of-Service (QoS) for supporting multi-missions of space station. According to characteristic of space station, a networking architecture for space station is presented. The slot allocation methods based on QoS are emphasized, and a demand slot allocation with QoS guarantee based on reservation is proposed. Using NS2 and STK, the results of simulation show that the propagation delay between space station and ground varies from 0.232s to 0.35s, and that the less active payload or spacecraft number is, the less End To End (ETE) delay is.
Global optimization of gravity-assist trajectory with deep space maneuvers
Li Xiaoyu, Zheng Jianhua
2013, 33(1): 72-78. doi: 10.11728/cjss2013.01.072
Abstract(2113) PDF 487KB(1355)
The problem of optimal design of a multi-gravity-assist space trajectory with deep space maneuvers is studied. Based on the zero-sphere-of-influence and patched conic hypothesis, the deep space trajectory is split into segments linked by deep space maneuvers and gravity assists. After introducing an auxiliary angle and B plane, the outgoing excess velocity could be expressed analytically. The deep space maneuver was computed by solving Lambert problem and trajectory propagation. The differential evolution algorithm is used to handle afore mentioned global optimization problem. Three cases to Jupiter, with gravity sequences of Venus-Earth-Earth (VEE), Venus-Earth-Mars-Earth (VEME) and Venus-Earth-Venus-Earth (VEVE) have been optimized.
Autonomous navigation based on pulsar in libration point orbit of sun-earth system
Yang Chengwei, Zheng Jianhua, Li Mingtao, Deng Xinping
2013, 33(1): 79-84. doi: 10.11728/cjss2013.01.079
Abstract(2312) PDF 458KB(1118)
The application of X-ray pulsar navigation in libration point orbit was discussed. The principle of X-ray pulsar autonomous navigation was analyzed. Difference between the real time and the estimated time of pulse arrival was regarded as the basal measurement. The system model was the full ephemeris dynamic model of Halo orbit around L1 point of the Sun-Earth system. The Unscented Kalman Filter (UKF) based on UD factorization was applied to estimate the state of the system. Perturbation factors were discussed to analyze their influence on navigation precision. The simulation results demonstrate that this algorithm is feasible for the autonomous libration point orbit determination in the Sun-Earth system. The method that applies full ephemeris dynamic model and X-ray pulsar-based navigation principle can accomplish the autonomous navigation mission in the libration orbits. Besides, the navigation results are able to converge and the accuracy is enough to meet the navigation demand.
Improved equivalent rotation vector based attitude updating algorithm of strapdown inertial navigation system under highly dynamic environment
Du Jiyong, Zhang Fengming, Li Jianwen, Huang Guorong, Dai Feng
2013, 33(1): 85-91. doi: 10.11728/cjss2013.01.085
Abstract(2117) PDF 467KB(1375)
The navigation algorithm of Strapdown Inertial Navigation System (SINS) under highly dynamic environment is studied, which is the key technology to improve the accuracy of SINS. The quaternion and equivalent rotation vector algorithms of resolving the attitude matrix were analyzed, and the equivalent rotation vector algorithm was developed in view of the application problem under highly dynamic environment. Aiming at adapting the algorithm to the application in highly dynamic flight environment, an improved equivalent rotation vector algorithm was proposed on the basis of coning motion environment, and the calculation error was derived. The performance was compared to one-sample and three-sample rotation vector algorithms. Simulation results indicate the effectiveness of the improved algorithm.
Design of the static calibration test system for Lorentz actuators in space application
Li Peng, Ren Weijia, Li Zongfeng
2013, 33(1): 92-100. doi: 10.11728/cjss2013.01.092
Abstract(1866) PDF 887KB(1269)
The static calibration test system for Lorentz Actuators of active payload-level vibration isolation system for experiments in space is systematically studied by simulations and tests. In order to meet the demand for real-time changes controller outputs in high quality microgravity vibration isolation system, actuator design parameters should be inspected and the relationship between output force and the input current should be deduced. A test system was designed, and its hardware structure, software model as well as the test program diagram, were introduced. The system hardware contains force sensors, force value shows, three axis displacement control apparatus, motor drive module and data receiving and distribution module. The LabVIEW programming technology was utilized in the system software to realize signal sampling, data displaying and storage. Finally, Matlab was used to process data. The test results provide technical basis for further optimal design of the actuators. By fitting error graphics, the correctness and rationality of the system design were verified, which provides a reliable guarantee for the normal operation of the active vibration isolation system.
Effects of enhancing power on received signal quality in satellite navigation system
Lv Zhicheng, Nie Junwei, Liu Zengjun, Wang Feixue
2013, 33(1): 101-107. doi: 10.11728/cjss2013.01.101
Abstract(2275) PDF 871KB(1308)
The GPS modernization program plans to add M-code navigation signals which have the feature of beam power enhancement in the frequencies of L1 and L2. Taking GPS L1 M-code signal as example, the received signal quality, affected by power-enhanced signal from the aspects of spectral overlap as well as equivalent carrier-to-noise ratio of the received signals, is analyzed. Simulation results show that when GPS L1 M-code signal enhancement is within the range of 20dB, the anti-jamming performance of power-enhanced signal will be improved significantly and the equivalent carrier-to-noise ratio of non-power-enhanced signal drops less than 2dB. When the signal enhancement range surpasses 20dB, the quality of non-power-enhanced signal will drop rapidly attributing to the interference from power-enhanced signal. While, when keep on increasing the signal power, the value of equivalent carrier-to-noise ratio of power-enhanced signal will no longer increase after having reached certain extreme value.
Design and deploying characteristics analysis on two-stage helical repeated fold-unfold and lock-unlock solar wing
Hu Ming, Yuan Weidong, Chen Wenhua, Kong Fei, Qian Ping, Chen Changzu
2013, 33(1): 108-114. doi: 10.11728/cjss2013.01.108
Abstract(1905) PDF 598KB(2424)
Two-stage helical repeated fold-unfold and lock-unlock solar wing is designed. Its function analysis is conducted. Firstly, its working principle is analyzed. Based on the requirement of two-stage helical repeated fold-unfold and lock-unlock solar wing, technological parameters and specific structural parameters are determined. The fold-unfold and lock-unlock solar wing unfolding characteristic is analyzed. According to the transitive relation analysis of repeated fold-unfold and lock-unlock solar wing, the analysis modeling on its deploying kinetic characteristics, including forward kinematics and inverse kinematics, are derived. Simulation results show that plane degree and synchronization degree of the solar wing can meet the requirements of specifications, which lays the theoretical foundation to further research the fold-unfold and lock-unlock solar wing in the future.
Radiation patterns of big antennas based on optics measurement
Wang Hongjian, Hao Qiyan, Yi Min, Chen Xue, Liu Guang, Liu Shihua, Zhao Xin
2013, 33(1): 115-119. doi: 10.11728/cjss2013.01.115
Abstract(1877) PDF 536KB(1045)
A new method to measure the large-aperture antenna radiation patterns was proposed. It is difficult for far-field, near-field and CATR measurement to meet the measurement requirements of electrically large antenna. Surface measurement of parabolic reflector antenna by photogrammetry at multiple points can achieve high accuracy, even electronic theodolite and laser interferometer can achieve more accuracy to meet surface measurement requirement of large-aperture terahertz antenna. This method used the data obtained by actual optical measurement to simulate the real antenna radiation by physical optics method. Because of using the real antenna measured data, this simulation method gave the actual antenna gain and radiation results. The simulation results agreed well with the antennas patterns obtained by the real near-field tests. This method was fast and much adaptable for the large-aperture antenna.
Research on photometric correction of lunar image from CCD stereo camera onboard Chang'E-1 satellite
Chen Chao, Qin Qiming, Lu Yan, Wang Jinliang, Zhang Ning
2013, 33(1): 120-127. doi: 10.11728/cjss2013.01.120
Abstract(2475) PDF 4475KB(1394)
In order to fit coefficients of the phase function more accurately and obtain some accurate results, Lommel-Seeliger factor has been revised according to the characteristics of CCD stereo camera data of Chang'E-1. By effective revision, the incidence angle and instrument viewing angle effect have been removed. The corrected image data fit much better with the variable trend of phase angle. Then photometric correction on the CCD stereo camera data of Chang'E-1 has been carried out pixel by pixel using the improved Lommel-Seeliger photometric correction model introduced by the revised Lommel-Seeliger factor. Finally, this algorithm has been verified by two groups of data from different latitudes of the same orbit and different view angles of the same area, respectively. The experimental results show that this method could effectively correct the inconsistency of the spectral characteristics of the object induced by the change of observation conditions. Moreover, using this method, photometric correction shows better performance even at brighter or darker areas.
2013, 33(1): 128-128.
2013, 33(1): 128-128.
Abstract(644) PDF 312KB(1485)