GPS测高技术在无验潮水深测量中的应用   总被引：8，自引：5，他引：8  

欧阳永忠  陆秀平  孙纪章  黄谟涛  翟国君  许家琨  申家双  王克平  刘传勇  侯世喜 《海洋测绘》2005,25(1):6-9,13

应用双频GPS动态后处理高精度定位技术，建立了一套完整的GPS无验潮海洋深度测量作业模式，通过海上试验与传统作业模式作了数值分析比较，结果表明，该作业模式不仅无需验潮，而且能够有效消除传统作业模式中船只动态吃水和涌浪等因素对测量成果的影响，显著提高水深测量成果的精度。  相似文献   

Improving Sequential Simulation with a Structured Path Guided by Information Content   总被引：1，自引：0，他引：1  

Yuhong Liu  Andre Journel 《Mathematical Geology》2004,36(8):945-964

Multiple-point simulation is a newly developed geostatistical method that aims at combining the strengths of two mainstream geostatistical methods: object-based and pixel-based methods. It maintains the flexibility of pixel-based algorithms in data conditioning, while enhancing its capability of reproducing realistic geological shapes, which is traditionally reserved to object-based algorithms. However, the current snesim program for multiple-point simulation has difficulty in reproducing large-scale structures, which have a significant impact on the flow response. To address this problem, we propose to simulate along a structured path based on an information content measure. This structured path accounts for not only the information from the data, but also some prior structural information provided by geological knowledge. Various case studies show a better reproduction of large-scale structures. This concept of simulating along a structured path guided by information content can be applied to any sequential simulation algorithms, including traditional variogram-based two-point geostatistical algorithms.  相似文献   

An Innovative Bias-Correction Approach to CMA-GD Hourly QuantitativePrecipitation Forecasts     

刘金卿  戴光丰  欧小锋 《热带气象学报(英文版)》2021,27(4):428-436

This paper proposes a simple and powerful optimal integration (OPI) method for improving hourly quantitative precipitation forecasts (QPFs, 0-24 h) of a single-model by integrating the benefits of different bias- corrected methods using the high-resolution CMA-GD model from the Guangzhou Institute of Tropical and Marine Meteorology of China Meteorological Administration (CMA). Three techniques are used to generate multi-method calibrated members for OPI: deep neural network (DNN), frequency-matching (FM), and optimal threat score (OTS). The results are as follows: (1) The QPF using DNN follows the basic physical patterns of CMA-GD. Despite providing superior improvements for clear-rainy and weak precipitation, DNN cannot improve the predictions for severe precipitation, while OTS can significantly strengthen these predictions. As a result, DNN and OTS are the optimal members to be incorporated into OPI. (2) Our new approach achieves state-of-the-art performances on a single model for all magnitudes of precipitation. Compared with the CMA-GD, OPI improves the TS by 2.5%, 5.4%, 7.8%, 8.3%, and 6.1% for QPFs from clear-rainy to rainstorms in the verification dataset. Moreover, OPI shows good stability in the test dataset. (3) It is also noted that the rainstorm pattern of OPI relies heavily on the original model and that OPI cannot correct for deviations in the location of severe precipitation. Therefore, improvements in predicting severe precipitation using this method should be further realized by improving the numerical model’s forecasting capability.  相似文献   

Impact of different sampling rates on precise point positioning performance using online processing service     

Serdar Erol  Reha Metin Alkan  ?.Murat Ozulu  Veli Il?i 《地球空间信息科学学报》2021,24(2):302-312

In this study, the effect of different sampling rates (i.e. observation recording interval) on the Precise Point Positioning (PPP) solutions in terms of accurac...  相似文献   

海道测量定位数据后处理的拟合算法研究          下载免费PDF全文

齐珺  暴景阳  黄晓杰  刘雁春 《海洋测绘》2010,30(4):1-4

根据海道测量定位数据后处理的要求,对定位数据后处理中的拟合算法进行了研究,提出了一种基于多面函数拟合的后处理方法,并给出了相应的数学模型。实例结果表明,后处理中采用多面函数拟合法处理测线定位数据可提高定位数据的可靠性,拟合精度可将精密动态定位控制在厘米级。上述方法有利于提高海道测量中海上定位成果的质量。  相似文献   

DGPS在广西沿海海底地形测绘中的应用     

徐承德  申宪忠 《海岸工程》1998,17(2):48-52

DGPS（DifferentialGlobalPositioningSystem）测量技术即差分定位技术,包括实时差分和后处理差分定位技术,正在远海和近海测量中得到广泛应用。后处理差分定位与微波定位及GPS实时差分定位相比,具有作用距离远,不受基准台与船台之问的障碍物影响以及减少基准台等优点。对于近海大比例尺（大于1：1万）测量,可采用实时差分定位的方法,而小于1：1万中小比例尺海底地形图测绘及海上其他工程测量,采用后处理差分定位,既能满足精度要求,又能提高工作效率。本文主要介绍利用DGPS后处理定位方法,在测绘广西沿海1：5万海底地形图中的应用情况。  相似文献   

T63系统中的资料同化     

张德新 《气象》1995,21(6):19-21

  相似文献   

多尺度的DMC彩色合成影像辐射再处理方法     

潘俊  王密 《武汉大学学报(信息科学版)》2007,32(9):800-803

在分析DMC（digital mapping camera）彩色合成影像存在的色彩过渡不平滑现象的特点和成因的基础上,提出了一种多尺度辐射再处理方法来改善影像质量。该方法采用多尺度处理策略,能自动定位拼接线和过渡区域的具体位置。实验表明,本文方法能够有效地改善DMC彩色合成影像的质量。  相似文献   

GRACE时变重力数据后处理方法评价     

姜永涛  王丽美  郭广猛  张子月  杨杰 《测绘科学》2021,46(3):21-26

针对GRACE Level2卫星时变重力数据后处理方法如何评价的问题,该文以中国数字地震观测网络获得的青藏高原地区地面重力变化图像为参考,基于平均结构相似性等图像相似度指标,研究了与该区域地面重力观测同期、不同后处理方法得到的GRACE卫星重力变化图像的可靠性。结果显示,GRACE卫星重力和地面重力观测结果具有一定的可比性,滑动窗口去相关滤波和高斯400 km滤波的组合方法可以获得最优的处理效果。本文的方法和结论对GRACE及GRACE Follow-On卫星重力数据应用中后处理方法和参数的选取有一定的借鉴意义。  相似文献   

春季中国日最高气温延伸期预报误差分析及订正     

熊敏诠  代刊  唐健 《热带气象学报》2020,36(6):795-804

数值模式直接输出和经模式后处理得到的预报误差比较,是延伸期逐日要素预报应用基础。针对中国2 583个站点在2020年春季11~30天的日最高温度预报,根据欧洲数值中心的集合预报输出,首先,使用BP-SM（Back-Propagation - Self memory）法和回归法,进行确定性预报订正效果比较;结果表明BP-SM法和回归法都明显降低了预报绝对误差;在11~14天预报中,BP-SM法得到的平均绝对误差为3.3~3.6 ℃,预报准确率超过35%,订正效果更优。其次,基于模式直接输出和BP-SM法获得的概率预报,使用CRPSS (continuous ranked probability skill score)进行了可预报性分析。结果表明,在地形复杂地区,经过订正,预报准确率明显改善。对于延伸期逐日要素预报,合理的模式后处理方法是降低预报误差和提高预报能力的重要环节。   相似文献