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31.
A.J. de Abreu P.R. Fagundes M. Gende O.S. Bolaji R. de Jesus C. Brunini 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
The responses of the ionospheric F region using GPS–TEC measurements during two moderate geomagnetic storms at equatorial, low-, and mid-latitude regions over the South American and African sectors in May 2010, during the ascending phase of solar cycle 24, are investigated. The first moderate geomagnetic storm studied reached a minimum Dst value of −64 nT at 1500 UT on 02 May 2010 and the second moderate geomagnetic storm reached a minimum Dst value of −85 nT at 1400 UT on 29 May 2010. In this paper, we present vertical total electron content (VTEC) and phase fluctuations (in TECU/min) from Global Positioning System (GPS) observations from the equatorial to mid-latitude regions in the South American and African sectors. Our results obtained during these two moderate geomagnetic storms from both sectors show significant positive ionospheric storms during daytime hours at the equatorial, low-, and mid-latitude regions during the main and recovery phases of the storms. The thermospheric wind circulation change towards the equator is a strong indicator that suggests an important mechanism is responsible for these positive phases at these regions. A pre-storm event that was observed in the African sector from low- to the mid-latitude regions on 01 May 2010 was absent in the South American sector. This study also showed that there was no generation or suppression of ionospheric irregularities by storm events. Therefore, knowledge about the suppression and generation of ionospheric irregularities during moderate geomagnetic storms is still unclear. 相似文献
32.
在第23至第24太阳活动周的峰年之间,太阳活动谷年具有持续时间长,极低F10.7太阳辐射通量(低至65)和超长期的零太阳黑子数记录等特点,因此是观测和研究在这种特殊背景下热层大气变化的极好机会.尤其是能充分理解和掌握在宁静环境下热层大气密度对弱太阳活动和小地磁扰动的响应特性.本文利用高度650 km以上星载大气密度探测器2007—2009年的连续探测数据进行分析,结果表明,在太阳辐射通量F10.7极低值期间,较高热层大气密度对F10.7的起伏具有更显著的响应变化.当F10.7由70降至65时,日均大气密度会有4~5倍的显著降变,远大于通常大气模式中的降变值.同样在F10.7极低值期间,较高热层大气密度对小地磁扰动也具有显著的响应增变,当日Kp指数之和由23增至30时,较高热层大气密度则会有80%~160%的强增变. 相似文献
33.
Tong Xu Yanli Hu Hanlu Zhang Zhi Chen Jian Wu Zhenwen Xu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
Earthquake prediction stimulates the searches for a correlation between seismic activity and ionospheric anomalies. Contrary to common focuses on strong earthquakes, we report the ionospheric disturbances, 2 days before a moderate Ms = 4.7 Chongqing earthquake (29.4°N, 105.5°E, depth = 7.0 km, occurred at 21:21 LT, 10 September, 2010) with the data of ground-based ionosondes and IGS receivers. The data covering the period under the quiet geomagnetic conditions and a geomagnetic storm was analyzed with upper and lower bounds. It is found that there were significant enhancements of foF2 and total electron content (TEC) on the afternoon of 8 September, 2010, with a limited area close to the epicentre, which was different from the feature of ionospheric perturbations triggered by the geomagnetic storm on 15 September. Taking into account the heliogeomagnetical condition, we conclude that the observed ionospheric enhancements were very likely associated with the forthcoming moderate Chongqing earthquake, which implies that the relationship between the amplitudes of ionospheric disturbances and earthquakes is very complicated. 相似文献
34.
李金猛 《长沙航空职业技术学院学报》2010,10(3):53-56,79
介绍用于自动控制设备控制板卡的软硬件设计方法,采用混合输入(包括SCH和VHDL)实现该设计,重点阐述应用ISP开发软件采用VHDL语言实现整个软件接收、控制部分,测试表明设计方法合理有效。 相似文献
35.
36.
P. Bencze I. Lemperger 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
The period of field line resonance (FLR) type geomagnetic pulsations depends on the length of the field line and on the plasma density in the inner magnetosphere (plasmasphere), where field lines are closed. Here as FLR period, the period belonging to the maximum occurrence frequency of the occurrence frequency spectrum (equivalent resonance curve) of pulsations has been considered. The resonance system may be replaced by an equivalent resonant circuit. The plasma density would correspond to the ohmic load. The plasma in the plasmasphere originates from the ionosphere, thus FLR period, occurrence frequency are also affected by the maximum electron density in the ionosphere. The FLR period has shown an enhancement with increasing F region electron density, while the occurrence frequency indicated diminishing trend (possible damping effect). Thus, the increased plasma density may be the cause of the decreased occurrence of FLR type pulsations in the winter months of solar activity maximum years (winter anomaly). 相似文献
37.
为了满足无人机三轴加速度测量与控制的需要,设计了一种简易、方便的加速度采集系统.本系统采用高集成度单片机C8051F020进行多通道数据的采集和A/D 转换,在单片机内部完成数据存储、数据处理,再利用串行通信接口将数据传送至上位机,然后由无线发射模块发送至地面接收设备.在试验条件下,可以将采集到的数据传送至PC机进行分析或者由液晶显示仪显示. 相似文献
38.
利用亚洲、澳大利亚地区8个电离层观测台站的F2层临界频率f0F2的历史观测数据,考察了NeQuick模式预报电离层基本参数f0F2在亚太扇区的适应性.对比分析表明,此模式能比较好地预测各地的F2层临界频率,其绝对误差在南半球各站相对北半球各站较大,太阳活动高年相对太阳活动低年较大,春秋季相对夏冬季较大.其误差均方根在太阳活动高年相对太阳活动低年较大. 相似文献
39.
40.
本文介绍了一种以SOC为核心芯片用于机载防撞系统(ACAS)中符合ARINC552A标准无线电高度信号激励测试的软硬件设计方法.采用C8051F020型SOC芯片及OPA552等芯片搭建仿真电路,利用PDIUSBD12接口芯片建立与工控机的通讯,依据ARINC552A标准,用C51编写仿真控制程序,将仿真的ACAS无线... 相似文献