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Table of Content

    15 July 2021, Volume 41 Issue 4 Previous Issue   
    Research Articles
    CME 3D-parameters Inversion by Cone Model
    WANG Zisihan, LUO Bingxian, WANG Jingjing, SUN Xiaojing, LIU Siqing, GONG Jiancun
    2021, 41 (4):  525-536.  doi: 10.11728/cjss2021.04.525
    Abstract ( 15 )   PDF (4229KB) ( 10 )   Save
    CME can affect the near-earth space environment and cause a geomagnetic disturbance. Therefore, it is of great application significance to predict whether and when it can reach the earth. Due to the limitation of observation ability, 3D-parameters are usually obtained by using cone model fitting according to the coronagraph projection observation information of CME near the sun, and then the effectiveness on earth of CME can be predicted by empirical prediction or interplanetary propagation process simulation. In the process of fitting, coronagraph observation data at different times can be taken as input, or CME can be restricted to occur near flares for fitting, which may result in completely different CME 3D-parameters, thus seriously affecting CME propagation prediction results. This paper selects a full halo CME event and a partial halo CME event, analyzes the changes of CME 3D parameter fitting results caused by different data input and fitting methods, and evaluates their impact on CME propagation prediction. The study found that the 3D-parameters of CME obtained by different data sources and fitting methods were significantly different, which affected the prediction of the ground validity of CME. In the future, it is necessary to evaluate the input data adopted and the fitting method, so as to predict the effects on earth of CME more accurately.
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    Distribution Characteristics of the Geomagnetic Induced Currents at High Latitude during Solar Cycle 23 and 24
    WEI Jiayun, ZUO Pingbing, SONG Xiaojian, ZHOU Zilu
    2021, 41 (4):  537-545.  doi: 10.11728/cjss2021.04.537
    Abstract ( 14 )   PDF (3200KB) ( 11 )   Save
    Based on the data of the Geomagnetic Induced Currents (GIC, IGIC) in the natural gas transmission pipelines in the high-latitude Mäntsälä area, Finland, from 1999 to 2017 during the recent two solar cycles. The distribution characteristics of GIC disturbances and the relationship between strong GIC disturbances and magnetic storms and substorms are analyzed. It is found that for 95.83% of the data points, the GIC intensity was distributed between 0A and 1A. The occurrence probability of GIC disturbance defined as |IGIC|max>1A, is highest near the nightside in MLT, which is possibly related to the stronger ionosphere current disturbances during the magnetospheric substorm at the nightside. All the intense GIC disturbances defined as the events with |IGIC|max>10A are accompanied by geomagnetic storms. Strong GIC disturbance events mainly occur in the main phase and the recovery phase of the magnetic storms, which are driven by ring current enhancement and have a longer time-duration and greater intensity. On the other hand, there are also a few events with a much shorter duration occurring with the storm sudden commencement. These events are caused by the sudden compression of the magnetosphere.
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    Finite-angle Magnetosphere Boundary CT Reconstruction Technique Based on Generative Adversarial Networks
    WANG Jiaxuan, LI Dalin, PENG Xiaodong, SUN Tianran
    2021, 41 (4):  546-554.  doi: 10.11728/cjss2021.04.546
    Abstract ( 8 )   PDF (2460KB) ( 6 )   Save
    Soft X-ray imaging detection of the Earth's magnetosphere is the frontier direction of recent magnetosphere research. Research on the method of reconstructing 3D magnetic layer boundary from 2D X-ray image is an important research topic related to imaging detection. Traditional Computer Tomography (CT) reconstruction methods cannot obtain good reconstruction results when image data is small, or even fail to reconstruct 3D structures. Considering the constraints on the spatial distribution of the Earth's magnetosphere, the orbital design of current satellite missions is difficult to meet the full angle coverage of the scanning angle, and the magnetosphere can only be observed from a finite angle, which brings problem to the CT reconstruction of the magnetosphere. As the basis of the 3D reconstruction research, this paper examines a simplified 2D magnetospheric reconstruction method, and uses CT technology based on adversarial neural network to reconstruct the simplified magnetosphere layer boundary structure. First, we use an improved Generative Adversarial Networks (GAN) to complete the finite-angle satellite scanned image, and then the magnetosphere layer is reconstructed using an Algebraic Reconstruction Technique (ART) reconstruction method. Experiments show that when the scanning angle is greater than 90°, the Generative Adversarial Networks can effectively and accurately complete the missing image, and the reconstruction effect is better.
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    Study of Plasmaspheric Electron Content Based on Precise Orbit Determination Data of COSMIC Radio Occultation
    FU Weizheng, MA Guanyi, WAN Qingtao, LI Jinghua, WANG Xiaolan, LU Weijun
    2021, 41 (4):  555-561.  doi: 10.11728/cjss2021.04.555
    Abstract ( 15 )   PDF (1536KB) ( 8 )   Save
    Plasmasphere is one of the most important parts in the solar-terrestrial environment. With the intention of plasmasphere study, podTec file from the satellite Precision Orbit Determination (POD) data of COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) occultation is used to obtain Plasmaspheric Electron Content (PEC). After data processing, PEC information from podTec (pod-PEC) is compared with the PEC provided by IRI-Plas model (IRI-PEC), and their values are found to have good consistency. pod-PEC data from COSMIC of March, June, September and December in 2014 of maximum solar activity are used to obtain PEC in low (0°—20°), middle (20°—50°) and high (50°—90°) modified dip (modip) latitude. Following conclusions are obtained. PEC decreases with the increase of latitude. The north-south symmetry of PEC about the magnetic equator in low and middle latitudes is better in March and September, and PEC in all latitudes of the northern hemisphere is significantly higher than that in the same latitudes of the southern hemisphere in June. However, even the PEC in the mid-latitudes of the southern hemisphere is equal to the PEC in the low latitudes of the northern hemisphere in December. The PEC value in the daytime is higher than that at night, and the diurnal variation of PEC in high-latitude area is not obvious. The PEC maximum value appears in the spring of the northern hemisphere, followed by winter and autumn, and the minimum occurs in summer, which shows an obviously annual anomaly.
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    Statistical Characteristics of Ionospheric Scintillation in China Based on the Data of GNSS during 24th Solar Cycle
    LIU Kun, SHENG Dongsheng, SUN Shuji, ZHU Qinglin, LI Jingjing
    2021, 41 (4):  562-567.  doi: 10.11728/cjss2021.04.562
    Abstract ( 13 )   PDF (1722KB) ( 4 )   Save
    Based on the data of GNSS ionospheric scintillation monitoring stations in China during the 24th solar cycle, the characteristics of ionospheric scintillation was carried out in middle and low latitudes in China. The statistical results showed that: ionospheric Scintillation mainly occurred in the spring and autumn equinox and during 20:00—02:00LT at night; in the area south of 28°N, the lower the latitude, the higher the intensity and probability of ionospheric scintillation; the probability of ionospheric scintillation was positively correlated with solar activity, and the probability of ionospheric scintillation was higher in the rising year than in the falling year; the ionospheric scintillation may occur under different condition intensities of geomagnetic activity, and which was negatively correlated with the intensity of geomagnetic activity. The results of the statistical study of ionospheric scintillation in this paper can provide reference for further study, prediction and engineering application of ionospheric scintillation mechanism.
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    A Prediction Model of the Grid Point Ionospheric TEC
    YIN Mengting, ZOU Ziming, ZHONG Jia
    2021, 41 (4):  568-579.  doi: 10.11728/cjss2021.04.568
    Abstract ( 15 )   PDF (2260KB) ( 4 )   Save
    A high-precision ionospheric TEC grid point prediction model is established using Gate Recurrent Unit (GRU) neural network model suitable for analyzing time series data. Ionospheric TEC grid point historical data, solar activity index, and geomagnetic activity index are used as inputs of our model. After our in-depth research and analysis, the data of 60 grid points were employed to predict model and do comparative experiments, and the results show that the mean value of average relative accuracy of the northern hemisphere is 83.96%, higher than 73.60% of the southern hemisphere. It presents that the adaptability of the prediction model is better in the northern hemisphere, and especially in the middle and low latitudes rather than in the high latitudes. The second result is that the mean value of the average relative accuracy of the prediction model in magnetic disturbance period is about higher 1.95% higher than that in magnetic quiet period. Finally, we compared the prediction results of several representative models. Compared with the single station prediction model based on RNN, LSTM and Bi-LSTM, the RMSE of this prediction model is reduced to 80.8% on average.
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    Design of Digital Control System for High-performance Ionosonde Based on FPGA
    JIN Mengya, GUO Wei, LIU Peng, WANG Caiyun
    2021, 41 (4):  580-588.  doi: 10.11728/cjss2021.04.580
    Abstract ( 11 )   PDF (3018KB) ( 3 )   Save
    This paper presents a high-performance ionosonde's digital control system design scheme, which is consisted of timing control unit, transmitting unit and receiving unit. This system is employed in electromagnetic synchronization verification system on the ground to establish integrated electromagnetic observation systems of heaven and earth with the electromagnetic satellite, to realize real-time accurate observation of the ionosphere, and to provide scientific and effective data for the study of earthquake mechanism and earthquake prediction. Under the radar timing control with variable transmission and reception delay, the transmitting unit uses Digital Frequency Synthesis (DDS) technology to generate pulse signals with the frequency range is 1MHz to 30MHz. The pulse signal is encoded by the 40-bit quasi-Barker codes in binary phase shift keying modulation, and orthogonally polarized waves are transmitted alternately by the antenna. The analog-to-digital conversion of the receiving unit is realized by a high-speed Analog-to-Digital Converter (ADC), and the Digital Down-Conversion (DDC) is carried out by the Field Programmable Gate Array (FPGA) technology. The polarization information of the echo signal can be caught by the ionosonde. The height resolution of the ionosonde is 1.5km, the detection period of the ionosonde is less than 2min. The verification results show that the digital control system scheme is feasible.
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    Simulation of the Middle and Upper Atmospheric Wind Measurement of THz Atmospheric Limb Sounder
    WANG Wenyu, WANG Zhenzhan, DUAN Yongqiang
    2021, 41 (4):  589-596.  doi: 10.11728/cjss2021.04.589
    Abstract ( 7 )   PDF (2359KB) ( 1 )   Save
    Middle and upper atmospheric wind is a key parameter in atmospheric science. Ground-based radar, lidar, and interferometer are usually used to measure the atmospheric wind. Up to now, the payload which can measure the atmospheric wind from space is quite scarce. Microwave limb sounding can also measure wind in the middle and upper atmosphere. THz Atmospheric Limb Sounder (TALIS) is the first Chinese microwave limb sounder being developed for atmospheric vertical profile observation. The main targets of TALIS are atmospheric vertical profiles of temperature, pressure and chemical species such as H2O, O3, HCl, ClO, N2O, HNO3. Since TALIS covers many strong lines, the observation data will contain doppler information of atmospheric wind, so it can be used to retrieve the atmospheric wind. In this paper, a simulation is performed to evaluate the precision of wind retrieval by using the Atmospheric Radiative Transfer Simulator (ARTS). The results suggest that 118GHz retrieval has a better precision of 12m·s-1 at 70km. The precision of 183GHz, 633GHz and 658GHz are 19m·s-1 (60km), 19m·s-1 (50km), 16m·s-1 (50km), respectively. 655GHz is a candidate band that has a large potential for wind measurement in the stratosphere and its precision is 11m·s-1 at 55km. The simulation also shows that reducing the spectral resolution to improve the NEDT has almost no contribution to a better retrieval precision. Reducing the system noise temperature is the only way to improve the precision.
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    Quantitative Estimations on the Gravity Wave Extraction Methods from Night-time Lidar Observation
    GAO Yingzhe, LIU Xiao, XU Jiyao
    2021, 41 (4):  597-608.  doi: 10.11728/cjss2021.04.597
    Abstract ( 12 )   PDF (6279KB) ( 23 )   Save
    According to temporal and spatial ranges and resolutions of night-time lidar observations, a synthetic data is constructed with known background temperature (consisting of constant background, planetary waves and tides) and gravity waves. The nightly mean method and the temporal running mean method are used to extract gravity waves from the synthetic data. Moreover, a harmonic fitting method is proposed, that uses a harmonic function to approximately represent the background changes and then to extract gravity waves. Based on the spectral response defined by the ratio between the extracted gravity waves and the known gravity waves, the reliable range of periods of gravity waves extracted by each method is quantitatively analyzed. Results show that: the nightly mean method always overestimates the amplitudes of gravity waves since it is particularly sensitive to background temperature components and the length of night time; the temporal running method is sensitive to semidiurnal tides and can be used to extract gravity waves with periods less than 1.15 times of the window width; the harmonic fitting method is not sensitive to background temperature components and can be used to extract gravity waves with periods less than 0.4 times of the night time. Finally, the temporal running mean method and the harmonic fitting method can get reliable gravity waves from the temperature data observed by Na lidar during nighttime.
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    Research on Global Stratospheric Gravity Wave Characteristics by AIRS Observation Data
    GUO Wenjie, YAO Zhigang, YANG Junfeng, HU Xiong
    2021, 41 (4):  609-616.  doi: 10.11728/cjss2021.04.609
    Abstract ( 11 )   PDF (6145KB) ( 4 )   Save
    The atmospheric infrared sounder mounted on the Aqua satellite has the advantage of directly measuring the temperature disturbance caused by gravity waves, and is therefore widely used in stratospheric atmospheric gravity wave research. The global distribution of stratospheric gravity wave activity intensity and occurrence frequency are analyzed using the 79th channel's observation data of the AIRS in January and July between 2012 and 2014. The variation characteristics of gravity wave activity with latitude and longitude are analyzed, and the hot-spot regions of gravity wave activity in the global range and their occurrence frequency are given. The similarities and differences between daytime and nighttime gravity wave activity intensity and occurrence frequency are compared. Results show that the gravity wave intensity varies significantly with latitude. In the low latitude area (0°—30°), the value of the gravity wave intensity in winter hemisphere is low, but is high in summer hemisphere. In the middle and high latitudes, winter hemisphere has strong gravity waves activity but the summer hemisphere gravity wave is weak. In January, there are four prominent hot-spots in the global range, located at 50° north latitude, the continental and Atlantic intersections, and the North American and Atlantic intersections, and at 20° south latitude, the South American and Atlantic intersections, and Africa intersection with the Indian Ocean. In July, the gravity wave activity was prominent in the Patagonia to Antarctic Peninsula region and the Indian Ocean region near 50° south latitude and 75° east longitude. Gravity wave activity intensity is greater at nighttime than daytime, but strong gravity wave activity zone is smaller at night.
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    Geomagnetic Day by Day Ratio and Its Relationship with Strong Earthquakes in Xinjiang and Its Adjacent Areas
    AISA Yisimayili, FENG Zhisheng, CHEN Jiehong, XING Hao, MAO Zhiqiang, ZU Qiang, ZHAO Jiaqing
    2021, 41 (4):  617-625.  doi: 10.11728/cjss2021.04.617
    Abstract ( 8 )   PDF (3043KB) ( 2 )   Save
    Daily variation of geomagnetic vertical component has important position in the study of earthquake precursor analysis. The variation magnetic field makes an induced magnetic field because of the Earth, conductivity, and the induced magnetic field includes the information not only from the outer magnetic field but also about the electrical conductivity of underground. The Earth's magnetic field geomagnetic vertical component reflects more changes of underground activity than other components. The method of day by day ratio with amplitude of geomagnetic vertical component is based on this theory. Because of this, This paper calculates the daily ratio of daily amplitude of geomagnetic vertical component by using the data at stations in Xinjiang and its surrounding areas, analyzes the characteristics of daily ratio and the earthquake cases in Xinjiang and its surrounding areas, analyzes the characteristics of daily ratio and the earthquake cases in north-south seismic belt. Opposed-phase induced magnetic field on opposite sides of the current was caused by daily ratio anomalies induced by underground current, and this formation mechanism is similar with the geomagnetic low point displacement anomaly. The study strengthened the reliability of using the method of day by day ratio to judge earthquake geomagnetic precursory anomaly information.
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    Characteristics of the Atmospheric Electric Field Distribution with Height in Qaidam Basin of Qinghai Province
    CHEN Tao, LI Lei, LI Wen, TI Shuo, WU Han, WANG Shihan, LI Renkang, LUO Fushan, ZHANG Huawei, SUN Hailong, SU Jianfeng, LUO Jing, WEI Feng, XU Qingchen, ZENG Chen, HE Zhaohai, DONG Wei, WANG Naiquan
    2021, 41 (4):  626-634.  doi: 10.11728/cjss2021.04.626
    Abstract ( 8 )   PDF (1813KB) ( 8 )   Save
    The intensity of atmospheric electric field is an important parameter of atmospheric electricity. Accurate measurements of atmospheric electric field and the analysis of its spatial and temporal characteristics are of great significance to study space weather activities, meteorological activities and geological activities. In the morning of August 26 and 28, the ballooning experiments with atmospheric electric field detector were done by Honghu Project of Chinese Academy of Science in Da Qaidam region of Qaidam Basin, Qinghai Province. By using cross-correlation function method and Principal Component Analysis (PCA) to analyze the data from the mill electric field instruments aboard the balloons respectively, it is demonstrated that although height is the main factor determining the strength of vertical atmospheric electric field, wind also has significant effect on the strength of the atmospheric electric field in this area. Under fair-weather conditions, the absence of thin clouds has some influence on the measurement of atmospheric electric fields. When there are clouds, the speed of wind will indirectly affect the atmospheric electric fields by affecting the formation of clouds. In addition, there is an atmospheric electric field boundary layer in the Qaidam Basin susceptible to the underlying surface. The thickness of this boundary layer is more than 3 kilometers. The changes in the atmospheric electric field in the boundary layer and the distribution of the atmospheric electric field above 3600m were analyzed and fitted when there were no clouds under fair-weather conditions.
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    Cross-calibration and Consistency of Microwave Sounder Data of Chang'E-1 and Chang'E-2 Satellites
    WANG Xueying, WANG Zhenzhan, ZHANG Dehai, JIANG Jingshan
    2021, 41 (4):  635-647.  doi: 10.11728/cjss2021.04.635
    Abstract ( 11 )   PDF (16231KB) ( 4 )   Save
    Chang'E-1 (CE-1)and Chang'E-2 (CE-2) orbiters were launched in 2007 and 2010, respectively, with the same microwave sounders CELMS (Chang'E Lunar Microwave Sounder). In-orbit calibration and time changes lead to differences between the CELMS data obtained by CE-1 and CE-2. To improve the consistency of CELMS data, the two-step calibration method is used to cross-calibrate CELMS data obtained by two orbiters based on permanently shadowed polar region of the Moon. Later, time correction was applied to reduce the effect of time on Brightness Temperature (TB). The analysis of TB at different latitudes shows that the two kinds of CELMS data have good consistency in 3GHz, 19.35GHz and 37GHz channels, while the 7.8GHz TB of CE-2 is higher than that of CE-1 in the low and middle latitudes, and the difference decreases with the increase of latitude. To avoid the effect of large longitude span, Mare Nubium impact basin was selected for further quantitative analysis of cross-calibration results. Analysis shows CELMS data are highly consistent in the region, and the average error is less than 0.2K. It is concluded that cross calibration and time correction significantly improve the consistency of the two observations and reduce the differences caused by measurement errors and time changes.
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    Single Event Latch-up Effect of 130 nm Bulk Silicon CMOS Device Irradiated by Pulsed Laser
    LI Sai, CHEN Rui, HAN Jianwei, SHANGGUAN Shipeng, MA Yingqi
    2021, 41 (4):  648-653.  doi: 10.11728/cjss2021.04.648
    Abstract ( 4 )   PDF (1904KB) ( 1 )   Save
    Based on the 130nm bulk silicon CMOS (Complementary Metal Oxide Semiconductor) process, inverter chains with different distance between well/substrate contact and MOS active, and the distance between NMOS active and PMOS active was designed. The Single Event Latch-up (SEL) characters of circuits with different designs and under various operation voltage were studied using the experiment of pulsed laser. Researches show that circuits will have higher sensitivity on SEL effect with the decrease of the distance between the well/substrate contact and the increase of the active distance between NMOS and PMOS. The decrease of the distance between the well/substrate contact and the active region of the MOS transistor represents the decrease of the well equivalent resistance and the substrate equivalent resistance. Therefore, a large induced current is needed to generate enough voltage drop to turn on the parasitic bipolar junction transistor, which eventually results in SEL effect. The increase of the active distance between NMOS and PMOS will reduce the partial voltage of the well parasitic resistance and the substrate parasitic resistance, which makes the parasitic bipolar junction transistor not easy to be triggered, so the SEL effect occurs difficultly. In addition, the SEL current increases with the increase of the operating voltage. Based on the parasitic structure in CMOS and the triggering mechanism of the SEL effect, the internal mechanism of related factors affecting the SEL sensitivity of circuits is analyzed.
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    Machine Identification of Throat Aurora
    TONG Xin, ZOU Ziming, BAI Xi, ZHONG Jia, HU Zejun, LI Bin
    2021, 41 (4):  654-666.  doi: 10.11728/cjss2021.04.654
    Abstract ( 8 )   PDF (3236KB) ( 0 )   Save
    Throat aurora is an auroral form frequently observed nearby the ionospheric convection throat region. Extending from the equatorward edge of the dayside auroral oval, and thus appears to be a north-south aligned discrete auroral structure. It is suggested to be the projection of the magnetopause reconnection process caused by the interaction between magnetopause and high-speed jets in magnetosheath. The investigation on throat aurora is meaningful for understanding solar wind-magnetosphere coupling process. It is the fundamental work of statistic study that identifying accurately and efficiently these special auroral structures from plenty of ASI images. Through preprocessing and labeling ASI images from Yellow River Station during 2003 and 2017, the throat auroral dataset is established, and the feature space of the auroral data is explored by using DenseNet and classified simultaneously based on whether an observation image has a structure of throat aurora, through which machine identification of throat auroral is achieved for the first time. The accuracy of the identification model is close to 96% and it has good generalization performance.
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    Auroral Oval Morphology Extraction Based on U-net from Ultraviolet Aurora Observation
    WANG Zihan, TONG Jizhou, ZOU Ziming, ZHONG Jia, BAI Xi
    2021, 41 (4):  667-675.  doi: 10.11728/cjss2021.04.667
    Abstract ( 6 )   PDF (3045KB) ( 0 )   Save
    Auroral oval morphology extraction plays an important role in the aurora research. How to improve the accuracy of auroral oval morphology extraction in ultraviolet aurora images with strong interference background is still an incomplete problem. In this paper, a method based on deep learning semantic segmentation model U-net is proposed. U-net model with residual block is used to extract auroral oval morphology with high accuracy. The experimental results on Polar satellite ultraviolet aurora images show that this method can get higher accuracy compared with the existing algorithms, and can obtain more detailed extraction results for both full auroral oval and gap auroral oval images. This method shows its advantages especially for aurora images with strong dayglow interference, uneven grayscale and low contrast. At the same time, the applicability and effectiveness of supervised deep learning method on auroral oval morphology extraction have been proved.
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    A Lossless Compression Algorithm for Astronomical Sequential Images Based on Hybrid Coder
    WANG Ying, ZHOU Qing, SONG Jinwei
    2021, 41 (4):  676-683.  doi: 10.11728/cjss2021.04.676
    Abstract ( 7 )   PDF (2378KB) ( 7 )   Save
    An image lossless compression algorithm based on time and space dimension prediction and hybrid entropy encoder is proposed. The algorithm is applied to the astronomical sequential imagery produced by fixed-point photography. The time and space dimension prediction can eliminate the time correlation and spatial correlation of astronomical sequential imagery, and the hybrid entropy encoder combined with high-entropy coding and low-entropy coding makes full use of the sparsity of the prediction error distribution. For sequential imagery, the algorithm first performs inter-frame prediction on time dimension to remove the time correlation, and then adopts histogram filtering and context prediction on spatial dimension for the residual imagery of inter-frame prediction to remove the spatial correlation. Finally, the prediction error is sent to the hybrid entropy encoder for coding. The experimental results show that the performance of the proposed algorithm is better than that of JPEG-LS, with an average compression ratio of about 15% improvement. The algorithm has simple structure and low computational complexity, which is friendly for hardware implementation and suitable for lossless compression of space astronomical imagery.
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    Research on Space Environment Information Service Composition Technology Based on Semantics
    WANG Jian, LU Guorui, CAI Yanxia
    2021, 41 (4):  684-690.  doi: 10.11728/cjss2021.04.684
    Abstract ( 7 )   PDF (1295KB) ( 3 )   Save
    With the rapid development of satellite technology and aerospace industry, ensuring the safety of the operation of space technology systems places higher requirements on the space environment forecast service. Based on the current situation of distributed integration and sharing of data and model resources in space environment information services, this paper applies Web service technology and semantic service combination technology to space environment information services to meet the needs of intelligent and automated generation of space environment forecast products. According to the characteristics of the space environment domain, a method for calculating the semantic similarity in the space environment domain is proposed, and a method based on semantic similarity is used to realize the automatic combination of space environment information services. The validity of service combination technology is verified by taking the generation of ionospheric TEC mapping data as an example, which can provide a reference for the research of remote sharing and automatic combination of resources in space environment.
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