基于PLSR的典型沼泽湿地植物叶片性状与光谱模型构建——以三江国家级自然保护区为例

通过植物光学特性测量叶片性状是一种非破坏性的、长期的湿地动态监测方法。选择三江国家级自然保护区多种典型湿地植物为研究对象,探究植物性状与叶片光谱之间的联系。研究表明：叶片氮含量与光谱的模型构建效果最好,模型R²为0.61,均方根误差（RMSE）为2.3862;叶片含水量、叶片磷、可溶性糖、纤维素和木质素含量之和的模型一般,R²在0.38~0.55范围内,RMSE在0.0004~10.7019范围内;淀粉含量拟合效果较差, R²为0.29,RMSE为0.0106。光谱预测重要性的结果表明,可见光与近红外边缘范围内的光谱信息对于叶片含水量、叶片氮含量、叶片磷含量、单位叶面积质量、纤维素和木质素之和、可溶性糖和淀粉的预测具有最高的重要性。     

Assessment of code bias variations of BDS triple-frequency signals and their impacts on ambiguity resolution for long baselines

GPS Solutions - Carrier phase ambiguity resolution over long baselines is challenging in BDS data processing. This is partially due to the variations of the hardware biases in BDS code signals and...     

An efficient solution of real-time data processing for multi-GNSS network

Global navigation satellite systems (GNSS) are acting as an indispensable tool for geodetic research and global monitoring of the Earth, and they have been rapidly developed over the past few years with abundant GNSS networks, modern constellations, and significant improvement in mathematic models of data processing. However, due to the increasing number of satellites and stations, the computational efficiency becomes a key issue and it could hamper the further development of GNSS applications. In this contribution, this problem is overcome from the aspects of both dense linear algebra algorithms and GNSS processing strategy. First, in order to fully explore the power of modern microprocessors, the square root information filter solution based on the blocked QR factorization employing as many matrix–matrix operations as possible is introduced. In addition, the algorithm complexity of GNSS data processing is further decreased by centralizing the carrier-phase observations and ambiguity parameters, as well as performing the real-time ambiguity resolution and elimination. Based on the QR factorization of the simulated matrix, we can conclude that compared to unblocked QR factorization, the blocked QR factorization can greatly improve processing efficiency with a magnitude of nearly two orders on a personal computer with four 3.30 GHz cores. Then, with 82 globally distributed stations, the processing efficiency is further validated in multi-GNSS (GPS/BDS/Galileo) satellite clock estimation. The results suggest that it will take about 31.38 s per epoch for the unblocked method. While, without any loss of accuracy, it only takes 0.50 and 0.31 s for our new algorithm per epoch for float and fixed clock solutions, respectively.     

Palynological Evidence of Late Pleistocene Soft-sediment Deformation Event in the Northeastern Margin of the Tibetan Plateau

The northeastern margin of the Tibetan Plateau is the youngest part of the Tibetan Plateau where tectonic activity is intense and climate change is complex. In this study, combined with field investigations, we explored accelerator mass spectrometry 14C and optically stimulated luminescence dating and palynological analysis of the sedimentary sequence in the Qingshuihe Basin to explain the origin of soft-sediment deformation layer. Dating and palynological results from the Sanchahe section in th...     

Impacts of Using the Rigorous Topographic Gravity Modeling Method and Lateral Density Variation Model on Topographic Reductions and Geoid Modeling: A Case Study in Colorado,USA

Surveys in Geophysics - Until now, the prismatic mass approximation of the topography and the constant density assumption have been mostly utilized in topographic reductions, which are rough...     

Correction to: Impacts of Using the Rigorous Topographic Gravity Modeling Method and Lateral Density Variation Model on Topographic Reductions and Geoid Modeling: A Case Study in Colorado,USA

Surveys in Geophysics -     

2022年1月8日青海门源MS6.9地震余震序列自动处理结果探讨

使用2022年1月8日青海门源M_S6.9地震前3天及后7天甘肃地震台网固定台站和邻省共享台站记录到的连续波形数据,利用RISP系统自动检测余震序列,并将检测结果与人工编目结果进行对比分析.结果表明:自动编目与人工编目定位结果基本一致,震中位置差(3.9±1.51)km,震级差值M_L(0.17±0.22);自动编目结果的发震时刻普遍略早于人工目录,但两种目录中大部分余震发生时刻的差值在2s内.自动编目产出速度快,且能检测人工无法识别的微小余震,提高了目录完备性.综合来看,自动编目系统产出结果符合预期目标,可为震群趋势判断、破裂过程快速反演等相关科学研究提供数据支撑.     

一种桩锚连接的新方法——双向支座法

阐述一种新型的在基坑及边坡支护工程中的传力装置——双向支座法,详细论述了目前普遍使用的腰梁工法的不足,并对其进行了改进,提出了新的施工方法,在基坑支护工程中具有较高的推广和实用价值。     

http://www.sciencedirect.com/science/article/pii/S1674987114000413

Braid-delta depositional systems are widely developed in most continental basins in China. Research indicates that, for different types of braid delta, the facies sequence and association, which are cr...     

基于Web Service的气象预警短信发布系统设计与实现

昆明市气象预警信息发布系统是以提高预警信息及时性和发布效率为出发点,整合了不同种类自动气象站的数据资源,与气象业务平台无缝集成,实时监控数据并生成满足需求的气象预警短信,通过预警号码管理数据库,确定预警信息受众范围,实现了预警短信服务的自动化、标准化、规范化。信息编辑不再需要人工干预,信息发布摒弃了原有的GPRS通信、GSMModem通信、运营商提供短信发布平台等方式,基于Web Service技术直接接入电信短信网关,实现了气象预警信息的高效发布,提高了气象服务的整体质量和效率。