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本文根据１９６０～１９９４年千里岩和青岛月平均气温资料，分析了千里岩与青岛３５年来气温的年、季变化特征及差别，发现３５年来，千里岩和青岛的年、季平均气温均呈变暖趋势，但千里岩增温幅度较青岛小。从分析中发现，与气温变暖趋势相对应，西北太平洋副热带高压（以下简称副高）面积、强度指数的年、季变化也呈明显的增强、增大趋势。且年平均气温与冬季副高面积指数相关最显著。最后依此关系建立回归方程，并预测了１９９６年千里岩年平均气温的变化趋势。 相似文献
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Wang Youcun Li Min Jiang Kecai Li Wenwen Zhao Qile Peng Hailong Lin Minseng 《GPS Solutions》2022,26(1):1-15
GPS Solutions - The precise satellite clock bias prediction is critical in improving the positioning, navigation and timing (PNT) service capabilities of the global navigation satellite system... 相似文献
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Low Earth Orbit satellite on-board accelerometers play an important role in improving our understanding of thermosphere density; however, the accelerometer-deri... 相似文献
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随着互联网技术的发展,利用互联网将观测站的实时GNSS数据高速传输给数据处理中心,可以打破GNSS数据事后处理的传统模式,从而实现GNSS数据的实时处理。对于数据处理中心而言,具备实时GNSS数据流管理功能的软件平台就显得尤为重要。本文主要对自主实现的实时GNSS数据流管理平台软件的实现及应用进行了介绍。该软件采用C/S框架设计,实现后端服务与前端用户界面相分离的效果,可通过网络与观测站建立连接来获取实时GNSS数据流,支持TCP/IP通信协议及NTRIP通信协议,支持解码RTCM3.X、BINEX等多种数据传输格式,能够汇聚分布在各地的观测站的GNSS数据,为后续的数据实时处理工作提供数据支撑,并在我国所发起的国际GNSS监测评估系统建设中得到应用。 相似文献
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开展海冰灾害风险评估和区划,有助于指导结冰海区沿岸各级政府制定和优化海冰防灾减灾决策,以最大限度地减轻海冰灾害造成的损失。本研究选取冰厚、密集度及冰期和各类承灾体密度、规模等作为评估指标,将河北省沿海县级行政区所辖海域作为基本评估单元,利用权重分析等方法,对河北省的海冰灾害风险进行综合评估。在此基础上,结合海冰防灾减灾的实际需求对河北省的海冰灾害风险进行空间区域的等级划分,并绘制风险等级分布图。所得结果较为真实地揭示了海冰灾害风险在河北省所辖海域的分布状况,可为河北省的海冰灾害风险管理等提供依据。 相似文献
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This study analyzes the quality of onboard data of tracking signals from GPS satellites on the far side of the earth and determines the orbit of the geostationary satellite using code and carrier phase observations with 30-h and 3-day orbit arc length. According to the analysis results, the onboard receiver can track 6–8 GPS satellites, and the minimum and maximum carrier to noise spectral densities were 24 and 45 dB-Hz, respectively. For a GPS receiver on a high-altitude platform above the navigation constellations, the blocking of the earth and a weak signal strength usually cause a piece-wise GPS signal tracking and an increase in the number of ambiguity parameters. Individual GPS satellites may be continuously tracked for as little as several minutes and as long as 3 h. Moreover, considering the negative sign of elevation angles reflects the fact that GPS satellites are tracked below the receiver in the study. GPS satellites appear mainly in the elevation angle range of ??53° to ??83°, and dilution of precision values could reach ten or one hundred and more. Also, it is observed that when a signal suffers from atmospheric refraction, other GPS signals tracked simultaneously by the receiver experience strong systematic errors in the code observations. Based on single-frequency code and carrier phase measurements, the mean 3D root mean square (RMS) value of the overlap comparisons between 30-h orbit determination arcs is 2.14 m. However, we found that there were also some biases in the carrier phase residuals, which contributed to poor orbit accuracy. To eliminate the effects of the biases, we established a correction sequence for each GPS satellite. After corrections, the mean 3D RMS was reduced to 0.99 m, representing a 53% improvement. 相似文献
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Min Li Wenwen Li Chuang Shi Kecai Jiang Xiang Guo Xiaolei Dai Xiangguang Meng Zhongdong Yang Guanglin Yang Mi Liao 《Journal of Geodesy》2017,91(11):1313-1327
The GNSS Occultation Sounder instrument onboard the Chinese meteorological satellite Fengyun-3C (FY-3C) tracks both GPS and BDS signals for orbit determination. One month’s worth of the onboard dual-frequency GPS and BDS data during March 2015 from the FY-3C satellite is analyzed in this study. The onboard BDS and GPS measurement quality is evaluated in terms of data quantity as well as code multipath error. Severe multipath errors for BDS code ranges are observed especially for high elevations for BDS medium earth orbit satellites (MEOs). The code multipath errors are estimated as piecewise linear model in \(2{^{\circ }}\times 2{^{\circ }}\) grid and applied in precise orbit determination (POD) calculations. POD of FY-3C is firstly performed with GPS data, which shows orbit consistency of approximate 2.7 cm in 3D RMS (root mean square) by overlap comparisons; the estimated orbits are then used as reference orbits for evaluating the orbit precision of GPS and BDS combined POD as well as BDS-based POD. It is indicated that inclusion of BDS geosynchronous orbit satellites (GEOs) could degrade POD precision seriously. The precisions of orbit estimates by combined POD and BDS-based POD are 3.4 and 30.1 cm in 3D RMS when GEOs are involved, respectively. However, if BDS GEOs are excluded, the combined POD can reach similar precision with respect to GPS POD, showing orbit differences about 0.8 cm, while the orbit precision of BDS-based POD can be improved to 8.4 cm. These results indicate that the POD performance with onboard BDS data alone can reach precision better than 10 cm with only five BDS inclined geosynchronous satellite orbit satellites and three MEOs. As the GNOS receiver can only track six BDS satellites for orbit positioning at its maximum channel, it can be expected that the performance of POD with onboard BDS data can be further improved if more observations are generated without such restrictions. 相似文献
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青岛气温变化趋势及其预测 总被引：1，自引：0，他引：1
根据青岛月平均气温资料（１８９８－１９９２年），研究了９５年来青岛年与季气温变化趋势。指出９５年来青岛年与季平均气温变化是上升的。其中春季增温最显著，冬季次之，秋夏增温最小。同时，根据年温度的变化趋势确定了气候转换期；１９０４－１９２９年为变冷期；１９２５－１９５３年为变暖期；１９５４－１９７９年为变冷期；１９８０年以后又是变暖期，预测该期的最暖时间将出现在９０年代初期。 相似文献
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