2015 Vol. 35, No. 6

Display Method:
An Introduction to Magnetosphere-Ionosphere-Thermosphere Coupling Small Satellite Constellation
LIU Yong, WANG Chi, XU Jiyao, LI Xiaoyu, CAI Jinrong, KONG Linggao, HUANG Jia, KLECKER Berndt, LEI Jiuhou, ZONG Qiugang, OCTAV Marghitu
2015, 35(6): 653-663. doi: 10.11728/cjss2015.06.653
Abstract(1817) PDF 2168KB(2730)
A future Chinese mission is introduced to study the coupling between magnetosphere, ionosphere and thermosphere, i.e. the Magnetosphere-Ionosphere-Thermosphere Coupling Small Satellite Constellation (MIT). The scientific objective of the mission is to focus on the outflow ions from the ionosphere to the magnetosphere. The constellation is planning to be composed of four small satellites; each small satellite has its own orbit and crosses the polar region at nearly the same time but at different altitude. The payloads onboard include particle detectors, electromagnetic payloads, auroral imagers and neutral atom imagers. With these payloads, the mission will be able to investigate acceleration mechanism of the upflow ions at different altitudes. Currently the orbits have been determined and prototypes of some have also been completed. Competition for next phase selection is scheduled in late 2015.
Observations and Fitting of Two Adjacent Impulsive Solar Energetic Electrons Events
Hu Zhongmin
2015, 35(6): 664-672. doi: 10.11728/cjss2015.06.664
Two adjacent impulsive Solar Energetic Electron (SEE) events were observed by WIND/ 3DP on November 15, 2010. The temporal profiles of the two events exhibit different behaviors: Event1 shows a rapid rise and rapid decay temporal profile, while Event2 shows a slow rise and very slow decay temporal profile with a duration 5~17 times longer than the duration of Event1. Based on previous studies, Event2 should have experienced much stronger scattering in the Interplanetary Medium (IPM), compared with Event1. However, the similar strongly anisotropic pitch-angle distributions of the two events observed at 1AU suggest the same weak scattering in the IPM (especially near 1AU). On the other hand, Event2 has harder peak flux versus energy spectrum than Event1. Using the telegraph equation with an isosceles-triangle injection function of time, the solar source and interplanetary propagation of these electrons are investigated and then the electron injection profile at the Sun and the electron mean free path in the IPM are obtained from the best-fit to in-situ observations. In Event1, the solar injection of low-energy (high-energy) electrons starts at 14:14±00:04UT (14:36±00:01UT) and lasts for about 50 minutes (about 7 minutes). In Event2, the solar injection of low-energy (high-energy) electrons starts at 14:34±00:13UT (14:25±00:02UT) and lasts for about 170 minutes (about 90 minutes). For both events, the electron energy spectrum during the electron solar injection does not become harder (continuously) with increasing time, suggesting the absence of electron storage in the corona (after acceleration). The inferred electron mean free path in the IPM is larger than that at 1AU for both events. These results suggest that for the two events, the different energy spectra and temporal profiles observed at 1AU were resulted from the electron acceleration at the Sun, not from the propagation effects in the IPM. By comparing the inferred electron injection times with GOES SXR and SOHO white light observations, these two events are likely associated with a CME.
Invariant Modulation of IMF Clock Angle on the Solar Wind Energy Input into the Magnetosphere
Han Jinpeng, Li Hui, Tang Binbin, Wang Chi
2015, 35(6): 673-678. doi: 10.11728/cjss2015.06.673
Abstract(911) PDF 724KB(1267)
By use of the global PPMLR Magnetohydrodynamics (MHD) model, a serial of quasisteady- state numerical simulations were conducted to examine the modulation property of the interplanetary magnetic field clock angle θ on the solar wind energy input into the magnetosphere. All the simulations can be divided into seven groups according to different criteria of solar wind conditions. For each group, 37 numerical examples are analyzed, with the clock angle varying from 0° to 360° with an interval of 10°, keeping the other solar wind parameters (such as the solar wind number density, velocity, and the magnetic field magnitude) unchanged. As expected, the solar wind energy input into the magnetosphere is modulated by the IMF clock angle. The axisymmetrical bell-shaped curve peaks at the clock angle of 180°. However, the modulation effect remains invariant with varying other solar wind conditions. The function form of such an invariant modulation is found to be sin(θ/2)2.70 + 0.25.
Effect of the 13 December 2006 Solar Radio Burst on GPS Observations
HUANG Wengeng, A Ercha, LIU Siqing, SHEN Hua, CHEN Yanhong
2015, 35(6): 679-686. doi: 10.11728/cjss2015.06.679
Abstract(1012) PDF 2106KB(1135)
Solar activity and Earth's space environment can effect the operation and safety of spacecraft, and they are also the main error source of navigation, positioning, and communication based on radio waves applications system. In this field, the L-band solar radio burst is regarded as a potential threat to Global Navigation Satellite System (GNSS) stability and performance. When the solar radio burst exceeds a threshold value, the radio noise from solar emission will increase dramatically, which can give rise to GNSS receiver tracking loss and positioning failure located in the sunlit hemisphere of the Earth. In this paper, by using the solar radio flux data, L-band scintillation data, and GPS receiver observation network data located in different regions, effect of the 13 December 2006 solar radio burst on GPS observations are investigated in detail. Results show that the disruption caused by this radio burst event is obvious, and the amplitude scintillation events occur and GPS signal losses of lock are detected. Furthermore, the GPS satellite signal locked at several GPS station is interrupted and the observed GPS satellite number is less than 4 during this solar radio burst. The event resulted in GPS service failure for about six minutes. By comparison, those stations located nearby sub-solar point are more serious than that of far away from it.
Analysis of the Chinese GEO Satellite Anomaly on 9 March 2012
TIAN Tian, WU Yaoping, CHANG Zheng, LI Ming, MA Liang, WEI Yali, ZHU Guoyang
2015, 35(6): 687-695. doi: 10.11728/cjss2015.06.687
Based on the GOES-15, SDO, SOHO satellites and geomagnetic indices data, the Chinese GEO satellite anomaly on 9 March 2012 was studied. The space weather conditions at the time of the GEO-X satellite anomaly are being analyzed, and SEAES-GEO (Spacecraft Environmental Anomalies Expert System for Geosynchronous Orbit) method is used to calculate the internal charging hazard quotient, the single event effects hazard quotient and the surface charging hazard quotient. The hazard quotient was divided into three types with red-yellow-blue color coding which represents different hazard rating. Results showed that the hazard quotient for internal charging was less than 3 and the surface charging hazard quotient was about 0.0011, safely in the green at the time of the failure. The hazard quotient for single event effects reached 46.3, which was correlated to high energetic protons produced during solar flares, very danger in the red at the time of the failure. The results thus imply that the single event effect is quite probably the reason that caused the GEO-X satellite anomaly on 9 March 2012.
Validation Study of FY-3A-TOU Total Ozone Using Ground-based Data
LIU Li, ZHENG Xiangdong, CHEN Shu, WANG Weihe, SHE Yong
2015, 35(6): 696-706. doi: 10.11728/cjss2015.06.696
Total ozone from July 2009 to December 2013 measured by Total Ozone Unit (TOU) borne on the FY-3A meteorological satellite is validated with the ground-based observations over the global five latitudinal bands, the north pole (north to 63.5°N), middle north of hemisphere (23.5°N~63.5°N), tropic zone (23.5°N~23.5°S), middle of south hemisphere (23.5°S~63.5°S) and South Pole (south to 63.5°S). The results show that the linear correlated coefficient between TOU and the ground-based data is more than 0.95. The globally average TOU Relative Difference (RD) from the ground-based data is (-0.16±4.3)%, with the respective of (0.6±3.8)%, (-0.5±3.9)%, (1.8±3.1)%, (-0.6±3.7)% and (-0.1±3.9)% over the 5 north-southward bands. The sensitivity tests suggest that TOU RD over the tropical zone evidently rises with the growth of the ground-based total ozone. The global TOU ozone RD reduces as the Solar Zenith Angle (SZA) is greater than 70° and the RD may reach from -4% to -10% as SZA from 75° to 85°. The TOU ozone RD is insensitive to the variability of cloud amounts and altitudes: the RD ranges within ±2% as the cloud amount changes from 0 to 100% or the cloud altitude changes from 1 to 15km. The TOU ozone RD is sensitive to the absorptive aerosol characterized by the positive Aerosol Index (AI), and it may decrease from -2% to -5% over the middle of south hemisphere as the AI from 1 to more than 2. The globally respective RD of TOU ozone to Dobson, Brewer and SAOZ observations is (0.6±0.17)%, (0.05±0.2)% and (0.04±0.01)%. TOU RD is generally negative as the Dobson or SAOZ total ozone is lower than 200DU, while it generally 2%~6% as SAOZ total ozone is 430~500DU. The respective RD of TOU to Dobson, Brewer and SAOZ is also insensitive to variations of SZA (less than 70°) or the cloud amounts, however, the RD of TOU respective to Brewer and SAOZ may behavior some small trend with the occurrence of high cloud or positive AI.
Capacity and Validation of Fabry-Perot Interferometer Wind Measurements in Shanxi of China
HUANG Cong, YU Tao, ZHANG Xiaoxin, WANG Jingsong, WU Qian, LI Tao, ZONG Weiguo, DUN Jinping, CUI Yingji
2015, 35(6): 707-714. doi: 10.11728/cjss2015.06.707
This article introduces the instrument structure of Fabry-Perot Interferometer (FPI), the capacity of wind measurements, the process of data reduction procedure, data quality control plan and data validation works which was deployed at Kelan Meteorological Bureau (39°N, 112°E) in Shanxi, China. The FPI of Kelan has the ability to measure the Doppler shift of airglow emissions (OH892.0nm, OI557.7nm, OI630nm) at mesopause and in thermosphere to derive horizontal wind vector and atmosphere temperature at heights of 87km, 97km and 250km, respectively. From late of 2011 to middle of 2014, a series of more than 6000 measurements at each height are derived according to manufacture data quality criteria. In data validation works, the Horizonal Wind Model (HWM) was applied to do the cross-comparison with Kelan FPI's observations. The comparisons show that the general trends of Kelan FPI's wind measurements are consistent with HWM's outputs and there exists difference of seasonal variation. The comparison results prove that the data quality control plan works and the measurement accuracies are 5.7m·s-1 at 87km, 1.3m·s-1 at 97km and 4.1m·s-1 at 250km height. In general, Kelan FPI's wind measurements are reliable and useful for investigations of the wind morphology in the mesosphere and thermosphere.
A New Method of Orbit Prediction for LEO Satellites Using Empirical Accelerations
WANG Wenbin, LIU Rongfang
2015, 35(6): 715-720. doi: 10.11728/cjss2015.06.715
Abstract(1157) PDF 857KB(1090)
A new method of orbit prediction for LEO satellites is proposed by using empirical accelerations to compensate for mismodelling of deterministic force models. The position, velocity and dynamical parameters such as CD, CR, and empirical accelerations are calculated in the orbit determination using reduced dynamic batch Least-Squares technique and GPS pseudorange observations. Therefore the position, velocity, CD, and CR can be used for prediction directly. Furthermore, the empirical accelerations are showed quasi-periodic and cosine characteristics with respect to time variable, in terms of which Fourier series were used to interpolate empirical accelerations. In this way, the fitted tangential empirical accelerations curve, which is added into deterministic force models to compensate for mismodelling of atmospheric drag model, forms enhanced-accuracy dynamic models that are used for orbit prediction. The GRACE-A real flight GPS pseudorange data and IGS Ultra-rapid products have been used to orbit determination and then the proposed method has been used to orbit prediction. The orbit determination results show that initial positioning accuracy is about 0.2m and velocity accuracy is about 1.0×10-4m·s-1. For a 72-hour orbit pass, the prediction accuracy is better than 60m, which is averagely improved about 2.3 times when compared to conventional dynamic models without considering empirical acceleration series fitting models. The proposed orbit determination and prediction scheme are beneficial to establish advanced, even onboard, satellite autonomous navigation system.
A New INS/VNS Integrated Navigation Method for Planetary Exploration Rover
Xu Yongzhi, Ning Xiaolin
2015, 35(6): 721-729. doi: 10.11728/cjss2015.06.721
Abstract(1189) PDF 1956KB(1203)
In traditional INS/VNS integrated navigation, the motion errors are usually used as the state vector, and relative motion errors between the inertial and vision navigation are used as the measurement. Since the relative motion is related to both the last and current states, traditional methods augment the position and attitude errors at the last time to the state vector to build the measurement model. The augmented states are considered as constant, and it generates new errors into the state model. Meanwhile, the measurement errors are analyzed based on ideal positions and attitudes at both the last and current time, which results in the measurement relationship with both the last and the current states. In this paper, a new INS/VNS model uses INS error equation as the state model, relative motion errors as the measurement, and attitude errors are described as quaternion error in the measurement model. The analyses of measurement errors are based on the integrated navigation estimation positions and attitudes at the last time, hence it does not need to augment the state, so the measurement only relates to the current state. The lunar surface simulation and experiment on the ground both show that the represented INS/VNS method can achieve high position and attitude estimation accuracy.
Orbit Determination Method Based on Thrust Force Model for GEO Satellite in the Period of Orbit Recovery
LI Xiaojie, HUANG Yong, GUO Rui, ZHU Lingfeng, SU Ranran, WU Shan
2015, 35(6): 730-737. doi: 10.11728/cjss2015.06.730
Real time, continuous and high precision navigation service is needed due to the frequent geostationary satellite (GEO) orbit maneuver. How to recover orbit rapidly for geostationary satellite based on short-arc tracking is the key factor. A new orbit determination method uniting the data before, during and after satellite maneuver is studied, and C-band transfer ranging data as well as the telemetry and telecontrol parameters during satellite maneuver are all used. The results based on observation data for geostationary satellite in Beidou System (BDS) indicate that the integrated solution strategy of orbit parameters and thrust force parameters needs to be adopted in the period of orbit recovery. The accuracy of 3-dimensional positions is about 20m, and the orbital precision in radial component is better than 2.5m using the data 4 hours after orbit maneuver. The method provides a solution to resolve several problems of dynamic orbit determination and point positioning in short-arc tracking.
Modeling and Control Strategy for a Flexible Spacecraft When it Encounters and Observes the Target
Zhang Qingzhan, Jin Yongqiang, Kang Zhiyu, Xiao Yuzhi
2015, 35(6): 738-745. doi: 10.11728/cjss2015.06.730
Taking advantage of encountering and observing is a very important approach for space situational awareness during space operations. For the modeling and control strategy of a flexible spacecraft when it encounters and observes the target in space, an analytic desired attitude motion law and an output feedback adaptive sliding mode control are presented. By defining the desired attitude coordinate system, the attitude pointing motion of the chaser when it encounters and observes the target is transformed to the coordinate system rotation. The analytic desired attitude motion law is derived based on the orbit motion in inertia coordinate system, and further is the relative attitude dynamic model of the flexible spacecraft when it observes the target. Based on this dynamic model, considering inertia uncertainty, flexible mode immeasurability and unknown bounded interference, the attitude sliding mode control containing inertia adaptive law and flexible modal-observer is obtained using Lyapunov stability theory, and the global asymptotic stability of the systems is proved. Simulation results show that the model and the control law are effective.
Echo of HF-band Radar Altimeter from Mars Based on a Multi-layer Media Model
Xu Xiyu, Liu Heguang, Yang Shuangbao
2015, 35(6): 746-754. doi: 10.11728/cjss2015.06.746
Abstract(684) PDF 641KB(1116)
The detection of water in Mars is currently one of the most striking issues in deep space detection. High Frequency (HF) radar altimeter has good penetrating ability and can measure the range and power simultaneously. In this paper, the principles and design of the altimeter system were presented, the interaction between the altimeter electromagnetic pulses and multi-layer smooth media was deduced, and the model of the echo power with respect to the time delay was extracted. Besides, the effects of Mars surface roughness were also considered. Finally, two typical Mars multi-layer models were adopted, and the dielectric constants and the altimeter echo waveforms were simulated. Results of the simulation show that the vertical dielectric constant profile of Mars subsurface could be retrieved by HF radar altimetry, and the water in Mars could be identified in certain cases.
A Satellite-borne Miniature Ion Mass Spectrometer for Space Plasma
Kong Linggao, Zhang Aibing, Zheng Xiangzhi, An Yaya, Wang Wenjing, Tian Zhen, Guan Yibing, Liu Chao, Ding Jianjing, Sun Yueqiang
2015, 35(6): 755-762. doi: 10.11728/cjss2015.06.755
Abstract(1015) PDF 296KB(1395)
The miniature design technology is an important trend in space exploration. Mass spectrometer is used extensively in the space environment detection. The miniature ion mass spectrometer utilizes a 127° cylindrical electrostatic analyzer accompanied with a Time of Flight (TOF) unit based on ultrathin carbon foil to measure the energy spectra and composition of space plasma. The Time of Flight technique has been used broadly in space plasma measurement. A new type of miniature method for the ion mass spectrometer is introduced. The total mass of the instrument is 1.8 kg and the total power consumption is 2.0W. The calibration results show that the energy measurement range is 8.71~43550eV, the energy resolution is 1.86% and the ion mass from 1 amu (1 amu = 1.67 × 10-27 kg) to 58 amu can be resolved by the miniature mass spectrometer. The miniature ion mass spectrometer also has a potential to be increased in the field of view by an electrostatic deflecting system to extend its application in space plasma detection. The miniature ion mass spectrometer has been selected for pre-study of Chinese Strategic Priority Research Program on Space Science.
Study on Technology of Using Semiconductor Diode Volt-Ampere Characteristic to Test Langmuir Probe Performance
LIU Chao, GUAN Yibin, ZHANG Aibing, SUN Yueqiang, LIANG Jinbao, ZHENG Xiangzhi, DING Jianjing, KONG Linggao, TIAN Zheng, WANG Wenjing
2015, 35(6): 763-768. doi: 10.11728/cjss2015.06.763
Abstract(949) PDF 797KB(1098)
A technique of using a semiconductor diode volt-ampere characteristic to test Langmuir probe performance is presented. The Langmuir probe is an important technique for in-suit detecting the space plasma, and its performance test is the key to ensure that its technical indicators can meet the mission requirements. The technique of using a semiconductor diode volt-ampere characteristic demands less of external factors, so it can be carried out in a laboratory environment. The test results can be used as preliminary performance verification before calibration test of ground plasma environment, and it is proved that the method is effective and feasible in a lab environment test.