2012 Vol. 32, No. 5

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China’s Space Astronomy and Solar Physics in 2011-2012
ZHANG Shuangnan, YAN Yihua, GAN Weiqun
2012, 32(5): 605-617. doi: 10.11728/cjss2012.05.605
Abstract(2416) PDF 159KB(1831)
In the first part of this paper, we describe briefly the mid and long-term plan of Chinese space astronomy, its preliminary study program, the current status of satellite missions undertaken, and the current status of astronomy experiments in China’s manned space flight program. In the second part, the recent research progress made in the fields of solar physics is summarized briefly, including solar vector magnetic field, solar flares, CME and filaments, solar radio and nonthermal processes, EUV waves, MHD waves and coronal waves, solar model and helioseismology, solar wind and behavior of solar cycle.
Research Progress of Solar Corona and Interplanetary Physics in China: 2010-2012
ZHAO Xinhua, XIANG Changqing
2012, 32(5): 618-646. doi: 10.11728/cjss2012.05.618
Abstract(2530) PDF 297KB(1316)
The scientific objective of solar corona and interplanetary research is the understanding of the various phenomena related to solar activities and their effects on the space environments of the Earth. Great progress has been made in the study of solar corona and interplanetary physics by the Chinese space physics community during the past years. This paper will give a brief report about the latest progress of the corona and interplanetary research in China during the years of 2010?2012. The paper can be divided into the following parts: solar corona and solar wind, CMEICME, magnetic reconnection, energetic particles, space plasma, space weather numerical modeling by 3D SIP-CESE MHD model, space weather prediction methods, and proposed missions. They constitute the abundant content of study for the complicated phenomena that originate from the solar corona, propagate in interplanetary space, and produce geomagnetic disturbances. All these progresses are acquired by the Chinese space physicists, either independently or through international collaborations.
Recent Progresses of Magnetospheric Physics in China: 2010-2011
CAO Jinbin, LIU Zhenxing, PU Zuyin
2012, 32(5): 647-664. doi: 10.11728/cjss2012.05.647
Abstract(2416) PDF 204KB(1268)
In the past two years, many progresses are made in magnetospheric physics by using either the data of Double Star Program, Cluster and THEMIS missions, or by computer simulations. This paper briefly reviews these works based on papers selected from the 80 publications from April 2010 to April 2011. The subjects covered various sub-branches of magnetospheric physics, including geomagnetic storm, magnetospheric substorm, etc.
Recent Progresses on Ionospheric Climatology Investigations
LIU Libo, WAN Weixing, CHEN Yiding, LE Huijun, ZHAO Biqiang
2012, 32(5): 665-680. doi: 10.11728/cjss2012.05.665
Abstract(2224) PDF 590KB(1920)
The ionosphere varies over multiple time scales, which are classified into two categories: the climatology and weather variations. In this national report, we give a brief summary of recent progresses in ionospheric climatology with focus on (1) the seasonal variations, (2) solar cycle effects, and (3) empirical modeling of the ionosphere. The seasonal variations of the ionosphere have been explored in many works to give a more detailed picture with regional and global features at various altitudes by analyzing the observation data from various sources and models. Moreover, a series of studies reported the response of the ionosphere to solar cycle variations, which revealed some novel and detailed features of solar activity dependence of ionospheric parameters at different altitudes. These investigations have improved our understanding on the states of the ionosphere and underlying fundamental processes, provided clues to future studies on ionospheric weather, and guided ionospheric modeling, forecasting and related applications.
Advances in Researches on the Middle and Upper Atmosphere in 2010-2012
CHEN Zeyu, CHEN Hongbin, LIU Xiao, HU Xiong, BIAN Jianchun, CHEN Wen, ZHANG Shaodong, XUE Xianghui
2012, 32(5): 681-692. doi: 10.11728/cjss2012.05.681
Abstract(2314) PDF 155KB(1917)
This article summarizes the researches on the middle and upper atmosphere by Chinese scientists in 2010?2012. The focuses are placed on the advances in construction of ground-based remote sensing facilities, the mean state and long-term changes in the middle atmosphere circulation, the prevailing dynamical processes, and the coupling of the middle atmospheric layers.
National Report on Space Medicine Progress in 2010-2012
LI Yinghui, LIU Zhaoxia, DING Bai, LIU Yue, ZHANG Xiaoyou, BAI Yanqiang, CHEN Shanguang
2012, 32(5): 693-703. doi: 10.11728/cjss2012.05.693
Abstract(2213) PDF 136KB(1595)
Accompanying the flourishing developments of China’s manned spaceflight, space medicine has achieved great development during the past two years in China. In this paper, scientific research of space medicine and its application in China during 2010?2012 have been briefly introduced.
Study on the Occurrence Rate of Spread-F’s Starting Time Observed in Hainan During Magnetic Disturbed and Quiet Days
LUO Zhixian, XIAO Saiguan, SHI Jiankui, GAO Taichang, WANG Guojun, FANG Hanxian
2012, 32(5): 704-712. doi: 10.11728/cjss2012.05.704
Abstract(2584) PDF 942KB(1003)
In this paper, a statistic study of the occurrence rate of spread-F's starting time observed at Hainan station was carried out by use of DPS-4 ionosonde data from February 2002 to December 2007 during the declining phase of the 23rd solar cycle under the conditions of magnetic disturbed and quiet respectively. Based on the spread F observations at Hainan ionosphere sounding station, the starting time statistics of various types of spread F are distinguished into Frequency type Spread F (FSF), Range type Spread F (RSF), Mixed type Spread F (MSF) and Strong range type Spread F (SSF). Results show that both on magnetic disturbed and quiet nights, the total occurrence rate of starting time of MSF is the highest. MSF performs as the most active one, FSF and SSF are secondary ones, and RSF is the least active one. MSF's starting time is mostly around midnight, while FSF's starting time falls into the post-midnight and SSF's starting time is pre-midnight. It is noticed that there is some difference in the starting time of MSF under magnetic disturbed and quiet nights. During magnetic quiet conditions, MSF tends to appear earlier than midnight and on magnetic disturbed nights it appears later. There is some correlation between the starting times of range and strong range types with solar activity. In the years of higher solar activity such as 2002, 2003, the occurrence rate of both types of spread F's starting time is higher in the time period of 20:00LT-22:00LT and 22:00LT-24:00LT under magnetic quiet nights than the one under magnetic disturbed nights, while in the years of lower solar activity such as 2005-2007, the occurrence rate of both types of spread F's starting time is higher in the time period of 00:00LT-02:00LT and 04:00LT-06:00LT during magnetic disturbed nights than the one under magnetic quiet nights. It is hoped that these results in this work is helpful for the study of morphology and mechanism of different type of spread-F.
Comparison Between the CHAMP/STAR Derived Thermospheric Density and the NRLMSISE-00 Model
WENG Libin, FANG Hanxian, JI Chunhua, ZHANG Yang
2012, 32(5): 713-719. doi: 10.11728/cjss2012.05.713
Abstract(2646) PDF 555KB(1296)
The derived thermospheric density from the CHAMP/STAR accelerometer observations has been compared with NRLMSISE-00 model, and the major results can be summarized as follows. The thermospheric density is lager in Equinoxes than Solstices, and this is much more notable in high solar level. The ratio between dayside and nightside thermospheric density in low-latitude during the high solar level is about 4 but reduces to 2 in low solar activity, and 3 to 1.5 in middle-latitude. NRLMSISE-00 model can capture the main character of the neutral density, but has lower performance during strong geomagnetic activities. This model overestimates density derived from satellite, and the relative errors are 16.512%, 20.004%, 18.915%, 18.245%, 25.161%, 33.261% and 41.980% from 2002 to 2008. The relative error in high latitude is 27.337%, but low-middle latitude is 24.047%. The model has a better performance under the conditions of middle solar activity level, and the relative error is about 15%.
Quantitative Analysis of Effect of Atmospheric Delay Error on InSAR Data Processing
YU Jingbo, LIU Guolin, CAO Zhentan, CUI Juan, LIU Hui
2012, 32(5): 720-729. doi: 10.11728/cjss2012.05.720
Abstract(3340) PDF 878KB(1298)
The effect approximate relationship formulas of the phase measurement error on height measurement by InSAR and deformation measurement by two-pass, three-pass and four-pass differential InSAR and the effect formulas of atmospheric delay error on the interferometric phase are put forward respectively, taking simultaneously into account the basic principles of the repeat track InSAR measurements. Then, the effect approximate relationship formulas of the atmospheric delay error on height measurement by InSAR and deformation measurement by two-pass differential InSAR, three-pass differential InSAR, four-pass differential InSAR are deduced respectively based on the above formulas. In the last place, the useful conclusions of the effect of atmospheric delay error on InSAR data processing are drawn by taking ERS-1 satellite system simulation experiments as an example and by talking over and analyzing the effect of atmospheric delay error on height measurement by InSAR and deformation measurement by two-pass differential InSAR, three-pass differential InSAR and four-pass differential InSAR etc.
Study on Autonomous Housekeeping of On-orbit Geostationary Satellites
LI Yuheng, LIU Zhen, HUANG Xingdi, ZHENG Jun
2012, 32(5): 730-738. doi: 10.11728/cjss2012.05.730
Abstract(2505) PDF 626KB(811)
Usually, it is the duty of ground satellite control centers to provide housekeeping service for on-orbit geostationary satellites. With the evolution in technologies and human cognition, if an on-orbit geostationary satellite can take over the task by itself, it will dramatically reduce the burden bore by ground satellite control centers, along with improving its independent survivability and lowering the entire system operation cost, perhaps being the future of on-orbit satellite management. This paper presents the key items of the housekeeping of a typical on-orbit geostationary satellite and studies algorithms which are used to control it. Then the possibility of autonomous housekeeping for an on-board satellite is discussed here. The result manifests that, even though the limit on orbit parameters acquiring, it is still possible for a satellite to manage itself in a short term without ground attendance or in a long run with a little attendance. Finally we design a prototype satellite, which is capable of serving housekeeping by itself. Taking into account such factors as the obstacle and risk to practically implement the proposal, some methods and measures are presented here. Our study shows that it is practical, based on the currently mature skill on satellite production and control, to produce such satellites with the ability of autonomous housekeeping. It may be an available way out of the dilemma between tough tasks caused by swelling satellites and the shortage of resource of ground satellite control centers.
Dynamic Properties of the Two-phase Loop Thermal Control System for Space Application
MO Dongchuan, LÜShushen, HE Zhenhui
2012, 32(5): 739-749. doi: 10.11728/cjss2012.05.739
Abstract(2229) PDF 926KB(1635)
Loop heat pipe with flat evaporator (Flat Loop Heat Pipe, FLHP) driven by capillary force and mechanical pumped two-phase loop (Tracker Thermal Control System, TTCS) are typical two-phase loop thermal control systems. The working principles of both FLHP and TTCS are discussed in this paper, and samples are tested. Also, dynamic models are built by both SINDA/FLUINT and Matlab/Simulink. The results show that both the FLHP and TTCS may have start-up problem, that the FLHP may have larger temperature oscillation, while the TTCS are more stable, that gravity has obvious effect on the FLHP performance, yet has no obvious effect on the TTCS performance, and that the FLHP with bi-transport loops has a better performance than that with single-transport loop, and the two radiators of the TTCS has the ability of self-adjust in mass flow rate and heat transfer. To choose a two-phase thermal control system, some items should be considered, such as the characteristic of the heat source, the life requirement, the temperature requirement, as well as the system size and mass, etc. Development of the two techniques may be cross-reference and complementary in future.
Design and Simulation for the Sensor of the Space Based Langmuir Probe
GUAN Yibing, WANG Shijin, LIU Chao
2012, 32(5): 750-756. doi: 10.11728/cjss2012.05.750
Abstract(2495) PDF 585KB(1098)
Langmuir Probe (LP) has been extensively used on satellites and sounding rockets for in situ measurements of the bulk parameters of the space plasma, i.e., electron density and electron temperature. LP sensor is usually a metallic electrode immersed in plasma for electrons and ions collection. Though the structure of the sensor is simple, there are many complex complications having to be taken into account for the design and implementation of LP investigations. There are three main factors for the sensor design, i.e., the shape, the dimension and the surface. The shape of LP sensor is mainly determined by the LP theory and end effects; the dimension is mainly determined by the signal intensity vs. capacity of the electronics, the LP theory vs. plasma environments, and the satellites or rockets conducting surface areas vs. sensor effective areas; the sensor surface should exhibit inherently uniform surface potential. All the variety complex complications above have been analyzed carefully and a prototype Langmuir probe has been designed. A simulation of the proto Langmuir probe has been done by the SPIS software, which shows the feasibility of the design.
Robust Control Based on Velocity Filter of Free-floating Dual-arm Space Robot System in Inertial Space
LIN Chengjin, CHEN Li
2012, 32(5): 757-764. doi: 10.11728/cjss2012.05.757
Abstract(2242) PDF 558KB(2301)
The robust control scheme based on velocity filter of free-floating dual-arm space robot system with uncertain payload parameters was studied. Through the Lagrangian approach, the dynamic equation of the free-floating space robot was modeled as under-actuated system. With the augmentation approach, it was demonstrated that the dynamic equations and the augmented generalized Jacobi matrix of the system can be linearly dependent on a group of inertial parameters, respectively. Based on the results, a robust controller based on velocity filter was developed for dual-arm space robot system with uncertain payload parameters to track the desired trajectories in inertial space. Ascribe to the pseudo-velocity signal acquired through the velocity filter, the proposed control scheme with only accurate positions of the joints and the end-effectors feedback avoid measuring the velocity and acceleration of the end-effectors. And it can avoid the control chatter effectively at the same time. The effect of the controller is testified by computer simulation.