ID 原文 译文
13554 研究电离层环境的长期变化特性, 获取电离层参数长期变化规律, 对通信导航、航天器等装备的设计和运行维护具有重要意义。 Studying the long-term variation of the ionosphere and obtaining the long-term change rule is important to the design and maintenance of communication navigation, spacecraft equipments.
13555 为了提高基于反向传输 (back propagation, BP) 神经网络的电离层foF2预测的精度, 采用了一种改进粒子群优化神经网络的方法, 对BP网络的初始权值进行优化, 防止出现神经网络训练中的局部最优。 In order to improve the ionospheric critical frequency based on BP neural network (foF2) prediction accuracy, we adopt a method of improved particle swarm optimization neural network method to optimize the initial weights of BP network to prevent the emergence of local optimal neural network in training.
13556 通过比较基于粒子群优化的神经网络预测结果与遗传算法优化的神经网络预测结果, 我们发现对于BP神经网络, 两种方法都有很好的性能。 By comparing the results of neural network prediction based on particle swarm optimization and the optimization of genetic algorithm, we find that the two methods have good performance for BP neural network.
13557 此外, 和电离层经验模型国际参考电离层模型 (international reference ionosphere 2016, IRI2016) 结果进行对比, 结果表明, 本文提出的自适应变异粒子群 (adaptive mutation particle swarm optimization, AMPSO) 优化神经网络能有效提高foF2的预测精度, 并在低纬地区有更好的预测效果。 In addition, compared with the international reference ionosphere model (IRI2016) , we find that the adaptive mutation particle swarm optimization neural network can effectively improve the prediction accuracy of foF2, and has better prediction effect in low latitude area.
13558 在2004年11月9—13日太阳质子事件期间利用224MHz雷达研究了连续五天出现的极区中层冬季回波 (polar mesosphere winter echoes, PMWE) , 发现电离层D区电子密度增强会增大PMWE的产生几率, PMWE强度越大, 其持续时间越长, 高度范围越大。 Through researching the polar mesosphere winter echoes (PMWE) of five consecutive days during the solar proton event detected by 224MHz radar from November 9th to 13th in 2004, we find that the enhancing ionization in D-region can increase the probability of PMWE production, and when intensity of PMWE is greater, the duration is longer and the height range is larger.
13559 由于白天D区的电离水平更高, PMWE在白天的出现率很高, 在夜晚很低。 In addition, the occurrence of PMWE during the days is high vhile the nights is low, because the ionization level of D-region during daytime is higher than night.
13560 通过深入分析发现, PMWE与宇宙噪声吸收 (cosmic noise absorption, CNA) 的极大值存在对应关系, 表明PMWE与高能粒子沉降导致的电离层D区电子浓度增强密切相关。 Moreover, the relation between PMSE and the maximum of cosmic noise absorption (CNA) is analyzed, and we find that the PMSE has a close relation with the increasing electron density in ionosphere D region due to the precipitation of high-energy particle.
13561 同时也发现, 极区中层冬季回波和极区中层夏季回波体反射率对频率的依赖性不同, 暗示二者的产生机理也可能有所不同。 At the same time, it is found that the polar mesosphere winter echoes and polar mesosphere summer echoes volume reflectivity are different depending on frequency, which may suggest that their mechanism may be different.
13562 由于射频干扰 (radio-frequency interference, RFI) 对星载微波遥感的影响日益严重, 为了比较各种识别方法的适用性, 基于先进微波扫描辐射计 (advanced microwave scanning radiometer 2, AMSR-2) 2015年冬季和夏季的观测亮度温度, 分别采用谱差法、多通道回归分析法、双主成分分析法和比值法, 对欧洲陆地区域和海洋区域的10.65GHz和7.3GHz频率干扰进行识别和分析, 并对比几种方法的月综合结果。 The influence of radio-frequency interference on microwave remote sensing has become increasingly serious.In order to better use the observed data, it is necessary to correctly identify and remove radio-frequency interference (RFI) contamination.To find out the applicability of various methods, the spectral difference method, multi-channel regression analysis method, double principal component analysis (DPCA) method and ratio method are used respectively to recognize RFI signals in the Advanced Microwave Scanning Radiometer 2 (AMSR-2) observations at 10.65GHz and 7.3GHz channels and the monthly results of above methods are compared.
13563 结果表明, 冬季时谱差法在陆地上受积雪散射的影响, 会将积雪下垫面误判为RFI污染。 Research shows, the spectral difference method is influenced by the scattering of snow and misjudged the underlying surface of snow as RFI pollution in land during winter.