江西兴国县溶解性总固体分布规律初探     

龚磊  王新峰  宋绵  张涛  吴玺 《地球学报》2018,39(5):587-592

本文聚焦于反映地下水宏量离子组分总量的溶解性总固体,应用统计描述、相关分析法、离子比例法分析了其在兴国县全境的分布演化规律。结果表明,兴国县89.8%采样点的溶解性总固体含量都处于200 mg/L以内,但存在空间分布差异显著,在松散岩类孔隙水、碎屑岩类孔隙裂隙水、变质岩类裂隙水和花岗岩类裂隙水中溶解性总固体的变异系数分别为0.37、0.77、0.56和0.59。对1977—2018年两期地下水水质数据分析,兴国县地下水中溶解性总固体不论是单点极值还是均值,均呈现大幅增加的趋势,其含量增幅在24.23%~458.13%之间。在空间分布上,溶解性总固体分布与高程具有较好的相关性,高溶解性总固体的地下水普遍分布在400 m高程以下。兴国县对地下水开发的增加,改变了地下水的补径排条件,加速了地下水与围岩和岩石矿物风化组分间的溶滤和离子交换,使Na+浓度减少,Ca~(2+)和Mg~(2+)含量增加。  相似文献   

Advances and Trends in Atmospheric Measurement by Smartphones*     

Xichuan Liu  Taichang Gao  Binsheng He  Lei Liu  Min Yin  Kun Song 《地球科学进展》2018,33(12):1223-1236

With the development and popularization of smartphones and embedded sensors, a non-professional atmospheric measurement method by using smartphones carried by the public has been proposed recently. Without extra dedicated instrument, this method has many advantages, such as low hardware cost, high spatio-temporal resolution, and wide coverage, and it can supplement the professional atmospheric measurement methods, which has broad applications in the meteorological operation, scientific research, public service, and other fields. At present, the research on the non-professional atmospheric measurement in China is limited. In order to make full use of this method, this paper briefly outlined the states of existing smartphones and embedded sensors, highlighted the measurement of precipitation, air temperature, pressure, aerosols, and radiation by smartphones. To promote the development of smartphones for atmospheric measurement, future research should focus on mechanism study, available sources exploration, data quality control, big data processing, joining and matching with operation, research and service, etc.  相似文献   

两方程湍流模型对内背风波数值模拟的影响          下载免费PDF全文

Xuhui Hu  Xuefeng Zhang  Lei Lin  Lianxin Zhang  Shifan Wang 《大气和海洋科学快报》2021,14(5):30-36

为了深入理解非静力近似下的波-湍相互作用问题,本研究在σ坐标的海洋环境研究和预报模型(MERF)中引入常用的Mellor-Yamada两方程湍混合参数化方案(MY2.5),评估垂向湍混合对小尺度背风波传播过程的影响.瞬时状态场的模拟结果表明,无论是否为非静力近似条件,上述湍参数化方案的引入都会减弱背风波传播的模拟效果.从时间平均场的试验结果来看,垂向湍混合过程会显著减小非静力近似和静力近似之间的差异.此外,能量收支分析的诊断结果表明,MY2.5方案会显著抑制陆坡地形下的背风波传播过程,进而将更多的潮能转化到不可逆的湍混合过程中.  相似文献   

深圳市连续运行参考站稳定性分析     

武曙光  聂桂根  邱蕾  汪善华 《测绘科学》2018,(6):78-82,87

针对深圳市连续运行参考站的稳定性分析相对较少的现状,基于深圳市2015年CORS数据,该文利用GAMIT软件计算并分析了参考站间基线以及与IGS站间基线的稳定性。结果表明,除因南山站点位异常引起了部分基线出现偏差外,大部分基线表现稳定且水平方向稳定性高于垂直方向。该文通过基线的稳定性分析方法,能够较为直观地检查出点位出现异常的参考站,这对于CORS站服务性能评估具有一定的参考意义。利用GLOBK软件平差得出了参考站坐标时间序列,并与PANDA的精密单点定位结果进行了对比分析;使用了SPSS软件的相关性分析法计算IGS站与参考站坐标变化的相关系数,得出SZCORS各参考站向东南方向偏移的趋势与板块漂移具有明显的相关关系这一结论。  相似文献   

校正地基摄影获取树枝倾角     

李雷  孟治国  郑兴明  赵凯  李晓洁  李晓峰 《测绘科学》2018,(5):109-114

针对传统树枝倾角测量方法的复杂性和精度低的问题,该文提出了通过校正地基摄影获取树枝倾角的方法。基于投影变换和小孔成像原理,通过自制树枝模型的方法,分析了直接图上量取树枝倾角与真实值之间误差的成因,提出了基于投影变化的树枝倾角计算公式。结果表明:该研究获取树枝倾角的相对误差2.72%明显优于传统测量的31.33%,同时随拍摄距离变化,树枝倾角估算结果具有稳定性。该研究方法简单、有效,非常适合复杂环境下树枝倾角的大量提取,并提出了一种基于摄影成像原理获取树枝倾角的方法,发展了树枝倾角测量系统软件,提高测量精度并降低了测量难度。  相似文献   

Super-resolution enhancement of UAV images based on fractional calculus and POCS     

Junfeng Lei  Shangyue Zhang  Li Luo  He Wang 《地球空间信息科学学报》2018,21(1):56-66

Abstract

A super-resolution enhancement algorithm was proposed based on the combination of fractional calculus and Projection onto Convex Sets (POCS) for unmanned aerial vehicles (UAVs) images. The representative problems of UAV images including motion blur, fisheye effect distortion, overexposed, and so on can be improved by the proposed algorithm. The fractional calculus operator is used to enhance the high-resolution and low-resolution reference frames for POCS. The affine transformation parameters between low-resolution images and reference frame are calculated by Scale Invariant Feature Transform (SIFT) for matching. The point spread function of POCS is simulated by a fractional integral filter instead of Gaussian filter for more clarity of texture and detail. The objective indices and subjective effect are compared between the proposed and other methods. The experimental results indicate that the proposed method outperforms other algorithms in most cases, especially in the structure and detail clarity of the reconstructed images.  相似文献   

郑洛地区史前聚落分布特征的空间自相关分析   总被引：1，自引：0，他引：1  

毕硕本  万蕾  沈香  陈昌春  贡毓成 《测绘科学》2018,(5):87-94

针对郑洛地区史前聚落遗址点的空间分布特征的问题,该文提出了一种空间自相关分析方法,以不同的格网尺度研究郑洛地区4个文化时期的遗址点的空间分布特征。研究发现:5 000~12 000m的格网尺度最能表现出裴李岗文化时期、仰韶文化前期、仰韶文化后期和龙山文化时期这4个文化时期全局自相关的差异。从局部自相关所表现出的变化情况来看,6 000~10 000m这一范围的格网尺度是最能保留住郑洛地区这4个文化时期遗址点的空间分布特征。将空间自相关分析应用于史前聚落考古研究中,可以探讨史前聚落考古中遗址点的空间分布模式及其变化。这不仅为史前聚落考古提供了一种新的思维方式,也扩展了史前聚落考古理论方面的研究。  相似文献   

An improved ionosphere interpolation algorithm for network RTK in low-latitude regions     

Jianhui Cui  Weiming Tang  Lei Jin  Chenlong Deng  Xuan Zou  Shengfeng Gu 《GPS Solutions》2018,22(4):109

A traditional interpolation algorithm with the linear interpolation method (LIM) using a fixed number of reference stations is widely used in network RTK to obtain the ionospheric delays for the users. In low-latitude regions, where the ionosphere is relatively active, however, large interpolation errors exist, especially for satellites at low elevation angles. Considering the characteristics of “coinciding ionospheric pierce points (CIPPs)” with a similar nature of ionospheric delays, an improved interpolation algorithm is proposed. In this algorithm, all stations with CIPPs are used to establish the interpolation model; thus, more precise interpolation model is achieved. To validate the performance of the proposed algorithm, data from some reference stations in Guangdong Province of China were used, and the results are compared with those with the traditional interpolation algorithm. Numerical analysis shows that the interpolation accuracy of the proposed algorithm increases by 10–30% compared with the traditional one. Since the number of reference stations is flexible, the proposed algorithm can also balance the model accuracy with the computation burdens. In addition, the proposed algorithm is less affected by the selection of master reference station. In terms of network RTK on-the-fly positioning, the time-to-first-fix is reduced when replacing the traditional interpolation algorithm with the proposed one.  相似文献   

辽宁省地理国情普查数据库管理与应用服务系统的开发与实现     

顾蕾 《测绘与空间地理信息》2018,(2):102-105

地理国情普查数据库管理与应用服务系统建设是地理国情普查项目中的重点工作之一,也是今后开展常态化地理国情监测的基础。本文简要介绍了辽宁省地理国情普查数据库管理与应用服务系统的架构、部署和功能实现以及系统的技术特点。  相似文献   

RTG与GPS相对定位联合作业的可行性分析     

敖德春  崔文刚  钟磊  袁航 《测绘与空间地理信息》2018,(2):134-137

近年来,RTG(Real Time Gipsy)技术的发展比较迅速,并且在一些行业中得到应用。本文阐述了GPS相对定位与RTG定位原理,并就GPS相对定位与RTG进行误差对比分析。根据行业标准与精度,对GPS相对定位与RTG在控制测量中联合作业的可行性进行探讨,提出联合作业的概念,主要为测绘人员布设控制网时提供参考,从而提高了工作效率,降低了项目成本。  相似文献