一种基于自适应窗口滤波的DEM获取算法

在分析了一种基于固定窗口滤波的DEM获取算法的基础上,提出了一种自适应窗口滤波的DEM获取算法,改变移动窗口的大小进行分块拟合来反演地面的高程值,获取DEM数据.利用海岸带区域IKONOS卫星影像匹配生成的三维坐标数据集进行了实验,实验证明了该算法的有效性.     

激光雷达数据处理、信息提取与应用

用于测绘的激光雷达技术的研究与应用在国际上已经经历了二十多年的发展历程.作为一种多平台主动探测技术,激光雷达已经和光谱成像技术以及合成孔径雷达一起构成当代遥感观测的核心技术体系.文章尝试对基于激光雷达数据的数据处理、信息提取及应用等进行综述,内容涉及点云分割、地物识别、点云滤波以及实际应用的最新研究进展.     

Trend analysis and ARIMA modelling of pre-monsoon rainfall data for western India

Spatial and temporal variability of rainfall over different seasons influence physical, social and economic parameters. Pre-monsoon (March, April and May – MAM) rainfall over the country is highly variable. Since heat lows and convective rainfall in MAM have an impact on the intensity of the ensuing monsoons, hence the pre-monsoon period was chosen for the study. The pre-whitened Mann Kendall test was used to explore presence of rainfall trend during MAM. The results indicate presence of significant (at 10% level) increasing trend in two stations (Ajmer, Bikaner). The practical significance of the change in rainfall was also explored as percentage changes over long term mean, using Theil and Sen's median slope estimator. Forecast using univariate ARIMA model for pre-monsoon months indicates that there is a significant rise in the pre-monsoon rainfall over the northwest part of the country.     

生物膜过滤深度净化水技术研究

以古交镇城底煤矿生活污水处理厂二级出水为研究对象,采用F/BF净化工艺,进行了污水深度处理的生产性试验。研究表明,该工艺对二级处理后的生活污水具有稳定、高效的净化能力,出水水质基本达到地面水Ⅳ类标准,可用于工业冷却水和低压水暖锅炉补充水,具有显著的经济效益和环境效益。试验还对不同滤料进行了分析,认为作为工业废料的炉渣是一种廉价、高效的新型生物膜过滤材料。     

The spatial patterns and determinants of internal migration of older adults in China from 1995 to 2015

Although China was one of the countries with the fastest-growing aging population in the world, limited scholarly attention has been paid to migration among older adults in China. The full picture of their migration in the entire country over time remains unknown. This study examines the spatial patterns of older interprovincial migration flows and their drivers in China over the period 1995 to 2015, using four waves of census data and intercensal population sample survey data. Results from eigenvector spatial filtering negative binomial regressions indicate that older adults tend to migrate away from low cost-of-living rural areas to high cost-of-living urban and rural areas, moving away from areas with extreme temperature differences. The location of their grandchildren is among the most important attractions. Our findings suggest that family-oriented migration is more common than amenity-led migration among retired Chinese older adults, and the cost-of-living is an indicator of economic opportunities for adult children and the quality of senior care services.     

强随机噪声条件下时窗类型局部线性化对TFPF技术的影响

为了更广泛地应用时频峰值滤波方法消减地震勘探记录中强随机噪声,本文比较详细地探讨了该方法在应用时需要处理的时窗选取、一个时窗内局部线性化等主要基础技术问题.经过时变时窗的仿真计算,运用多项指标比较,包括整体背景强弱、振幅谱、信噪比、均方误差、有效子波波峰波谷幅值、畸变程度,综合评价出（L₀+L_x）时窗滤波的效果较理想.对于三角波这类简单类型的周期波,其时频峰值滤波效果与边线段平均曲率变化、时窗长度等条件有关,即三角波边线段平均曲率越大,滤波结果的均方误差越大;另外,边线段平均曲率增大时,选取的时窗长度有变小的趋势.总之,在地震勘探中应用时频峰值滤波方法消减强随机噪声时,一方面要合理地选取时窗参数,另一方面时窗参数又不能变化过大,以避免对有效子波波形产生畸变影响.     

Paleocene large-scale normal faulting along the Median Tectonic Line, western Shikoku, Japan

Abstract   The Median Tectonic Line (MTL) in southwest Japan, a major east–west-trending arc-parallel fault, has been defined as the boundary fault between the Cretaceous Sambagawa metamorphic rocks and Ryoke granitic and metamorphic rocks, which are unconformably covered by the Upper Cretaceous Izumi Group. The juxtaposition by faulting occurred after the deposition of the Izumi Group. Based on detailed fieldwork and previous studies, the authors reconstruct the kinematic history along the MTL during the Paleogene period, which has not been fully understood before. It is noted that although the strata of the Izumi Group along the MTL dip gently, east–west-trending north-vergent folds with the wavelength of ∼300 m commonly develop up to 2 km north from the MTL. Along the MTL, a disturbed zone of the Izumi Group up to 400 m thick, defined by the development of boudinage structures with the transverse boudin axis dipping nearly parallel to the MTL, occurs. Furthermore, east–west-trending north-vergent folds with the wavelength of 1–5 m develop within the distance up to 60 m from the MTL. The disturbed zone with the map-scale north-vergent folds along the MTL, strongly suggests that they formed due to normal faulting with a top-to-the-north sense along the MTL. Considering that the normal faulting is associated with the final exhumation of the Sambagawa metamorphic rocks, and its juxtaposition against the Izumi Group at depth, this perhaps occurred before the denudation of the Sambagawa metamorphic rocks indicated by the deposition of the Lower Eocene Hiwada-toge Formation. Dynamic equilibrium between crustal thickening at depth (underplating) and extension at shallow level is a plausible explanation for the normal faulting because the arc-normal extension suggests gravity as the driving force.     

基于ARMA模型非因果空间预测滤波(英文)

常规频域预测滤波方法是建立在自回归(autoregressive,AR)模型基础上的,这导致滤波过程中前后假设的不一致,即首先利用源噪声的假设计算误差剖面,却又将其作为可加噪声而从原始剖面中减去来得到有效信号。本文通过建立自回归-滑动平均(autoregres sive/moving-average,ARMA)模型,首先求解非因果预测误差滤波算子,然后利用自反褶积形式投影滤波过程估计可加噪声,进而达到去除随机噪声目的。此过程有效避免了基于AR模型产生的不一致性。在此基础上,将一维ARMA模型扩展到二维空间域,实现了基于二维ARMA模型频域非因果空间预测滤波在三维地震资料随机噪声衰减中的应用。模型试验与实际资料处理表明该方法在很好保留反射信息同时,压制随机噪声更加彻底,明显优于常规频域预测去噪方法。     

基于滤波顾及起算数据误差的赫尔默特估计法

在参数和起算数据的先验统计性质已知时,提出了基于滤波的顾及起算数据误差的赫尔默特估计法。这种方法估计出了相对于起算数据基准的精度,既充分考虑了起算数据的影响又没有增加计算量,并且将平差计算与随机模型的赫尔估计同时进行,使数据处理过程更加完善。     

Linear Time-Invariant Compensation of Cup Anemometer and Vane Inertia

We propose a method to compensate for the phase lag and the amplitudeattenuation in the cup anemometer signal. These two effects, caused by theinstrument's inertia, are the major flaws of the cup anemometer in additionto over-speeding. Since the instrument's response is invariant in wavenumber (not frequency) representation, we transform the signals to becompensated from the time domain to the spatial domain by using Taylor'shypothesis. In the spatial domain we apply a linear time-invariant filterto eliminate the phase lag and the amplitude attenuation. The proposedprocedure improves instrument performance down to spatial scales equal toor smaller than the distance constant of the anemometer. The method for cupanemometer compensation is presented in detail and later adapted for vanes.