一种基于双频测绘无人船的淤泥厚度出图方法

测定河道底部淤泥厚度是整治黑臭河淤泥、构建河道良好生态的关键。然而,目前利用测绘无人船进行河底测量还无法直接生成淤泥厚度图。基于这一问题,提出一种双频测绘无人船的淤泥厚度出图方法。首先,使用无人船所装载的RTK和双频声呐进行坐标点数据采集;然后,分别对高频和低频点数据进行普通克里金格网插值,形成两个频段的规则格网数据;最后,结合杆高等固定参数设置,计算淤泥顶部和底部数据,从而得到淤泥厚度。通过对南京水西门外秦淮河河段实地测试和出图验证,该方法具有较高的精度和效率,能够为黑臭河的淤泥治理提供较为可靠的技术支持。     

无人船测量系统在河道清淤中的应用

采用基于网络RTK技术的无人船测量系统对河道水底地形进行测量,并对河道清淤前后淤泥方量进行了测算。结果表明,无人测量船在河道清淤测量中具有一定的可行性。定期用无人测量船对河道进行测量,掌控河道底部淤泥厚度变化情况,有利于河道清淤疏浚工作。     

数字水果湖水下地形和淤泥厚度测量

阐述了采用GPS接收机和双频数字测深仪 ,以伪距差分实时定位测量模式施测水果湖水下地形和淤泥厚度的全过程和若干技术问题 ,所得结果对水果湖的治理提供了可靠的资料 ,指出了武汉市湖泊治理的迫切性     

水下地形与淤泥厚度测量

目前,我国湖泊污染问题十分严重,主要是水质污染和淤泥污染,且湖泊测绘资料比较缺少。本文就某湖泊的整治作一阐述,较详细说明水下地形与淤泥厚度测量原理及方法。同时说明湖泊整治的重要性和迫切性。     

数字水准仪SPRINTER 200M的试验与评述

本文介绍了SPRINTER 200M数字水准仪的基本参数和特点，对SPRINTER、NA、DNA三个系列数字水准仪的参数进行了比较，给出了SPRINTER 200M初步试用情况及测试结果。     

X波段VV极化地面杂波测量研究

对X波段，VV极化的外场地杂波试验进行了总结，包括测量系统，原理，测试内容，并提供了后向散射系数测量结果和分析，测量地形包括干草地，裸露土壤和绿麦地。     

航空遥感辅助淤泥质海滩地形测量的研究

本文依据海滩所具有的既不同于陆地也不同于海洋的覆盖特性,对一直未能很好解决的淤泥质海滩地形测量问题,提出了航空摄影测量与水深测量相结合的方法。其特点在于滩地地形的平面位置用航测方法处理,高程采用经起算面改化的原始水深资料。试验结果表明,在等高距一米,比例尺1:5万的淤泥质海滩地形图上,其等高线高程中误差为0.38米。     

基于Matlab的激光测厚仪的误差分析及数据仿真

介绍测量炉壁厚度的方法并着重对测量结果进行误差分析,用Matlab对测量数据进行误差仿真.     

近景摄影测量用于水轮机叶片测绘

本文介绍了采用微型控制测量，交向摄影和计算机解析计算方法测绘水轮机叶型的测量过程，并提供叶型测绘检定精度的结果。为了精确和方便地求出叶片的厚度，采用了合理选择物方坐标系和布设透明标志的方法。     

GPS大地测量控制网的工程设计

全球定位系统卫星测量已经成为日常的测量工具，虽然它所达到的精度是用史无前例的技术，方案的主设计、实施，后处理与测试设备，在获得期望的结果中也起到了重要的作用。     

城市复杂排水管线点埋深的测量精度分析

通过对某市排水设施普查数据进行分析研究,得出当井底状况复杂时,《城市地下管线探测规程》对明显管线点埋深的测量精度要求已很难满足。数据分析显示,当井底状况较为复杂时(少量淤泥或积水)且管线点埋深在3m以下,排水管线点埋深的测量中误差的允许值建议取±10cm;埋深在3m以上时,排水管线点埋深的测量中误差允许值建议取±1/30 H(H为管线点的埋深);当井底状况极为复杂(淤泥较多、积水严重或水流湍急)时,排水管线点埋深测量限差建议按隐蔽管线点处理,建议取值为0.15 H。     

HYOROTRAC单频测深仪在二滩水电站库区泥沙淤积监测中的应用

迄今为止，声纳技术应用于江、河、湖、海水下地形测量，特别在大面积、深水域是最便捷、最有效的方法。本文着重阐述了HYOROTRAC单频测深仪在二滩水电站库区泥沙淤积监测中的应用，并解决了长期以来数据处理中忽视的问题。     

利用气象卫星资料分析长江口通海航道泥沙分布

利用气象卫星的时间、空间上的优势,在总结长江河口河槽演变基本模式的基础上,结合卫星图像的分析,确定和研究长江口泥沙地区悬移质的输移路线和活动范围,探讨分析了长江口悬浮泥沙浓度分布动态,分析了滩槽泥沙交换对航道淤积的影响,为长江口深水航道整治方案的确定提供了科学依据。     

中国海岸带分布规律及其海部要素变化检测

在海岸带图测绘完成后,海部要素的变化是导致海岸带图使用价值降低的重要因素。根据我国海岸的组成物质将其归纳为淤泥质海岸、沙砾质海岸、基岩海岸、红树海岸和珊瑚海岸,并归纳总结了每一种海岸的空间分布规律。分析了影响海岸线、干出滩以及近海水深等海部要素变化的主要因素,海岸要素变化的因素和变化规律,进而提出了海部要素实质性变化的检测统计方法,对提高海岸带图测绘效率、缩短成图周期、确定更新周期和制定更新方案都具有重要的意义。     

中国海岸带分布规律及其海部要素变化检测

在海岸带图测绘完成后,海部要素的变化是导致海岸带图使用价值降低的重要因素.根据我国海岸的组成物质将其归纳为淤泥质海岸、沙砾质海岸、基岩海岸、红树海岸和珊瑚海岸,并归纳总结了每一种海岸的空间分布规律.分析了影响海岸线、干出滩以及近海水深等海部要素变化的主要因素,海岸要素变化的因素和变化规律,进而提出了海部要素实质性变化的检测统计方法,对提高海岸带图测绘效率、缩短成图周期、确定更新周期和制定更新方案都具有重要的意义.     

福建省海岸带泥沙分布的气象卫星遥感监测

根据水体对太阳辐射光谱的反射率变化特性,利用NOAA极轨气象卫星遥感资料,动态监测福建省海岸带悬浮泥沙的分布,并从十几幅质量较好的不同时相的泥沙分布图中得出初步的监测结果。     

Assessment of sedimentation in harakud reservoir using digital remote sensing technique

As per recommendations of Working Group for National Action for Reservoir Sedimentation Assessment, National Institute of Hydrology has taken up study on sedimentation for 25 reservoirs in India during X plan period using remote sensing technique. One such study for Hirakud reservoir in Mahanadi basin in Orissa for year 1999–2001 is described here. Reservoir’s original utilizable and gross volumes were 5818 and 8136 M m³, respectively. Minimum draw down level (MDDL) and full reservoir level (FRL) for reservoir are 179.83 and 192.02 m, respectively. Linear Imaging Self Scanning (LISS)- III data of Indian Remote Sensing Satellites (IRS) 1C and 1D, covering elevation range between 180.68 and 191.89 m, were used. Rule based classification was applied to ‘water index’ and radiances of near infrared band to determine water spread area. Revised live storage capacity was 4842 M m³. The silt index for the live storage area was 2.623 ha m (100 km² year)^-1 (0.376 % of live storage or 21.9 M m³ year^-1). Total live storage lost in sedimentation was 984 M m³ (16.90 % of live storage).     

Diurnal variation of vertical temperature gradients within a field of maize: implications for Satellite microwave radiometry

We present the diurnal variation of vertical temperature differences measured within and beneath a maize canopy over the course of a growing season, and we analyze the implied temperature gradients in the context of microwave radiometry and soil moisture retrieval in particular. We find that the temperature differences can be as large as 9 K in magnitude within the vegetation canopy and as large as 10 K between the soil surface and a depth of 4.5 cm. Satellite overpass times at 1:30 A.M. and 1:30 P.M. occur close to when the magnitude of the temperature differences are largest. For 6 A.M. and 6 P.M. overpass times, temperature differences were smaller in magnitude at 6 P.M. This contradicts the widely held assumption that surface temperature gradients are more uniform at 6 A.M. than at 6 P.M.     

A nonlinear inversion of InSAR-observed coseismic surface deformation for estimating variable fault dips in the 2008 Wenchuan earthquake

Satellite Interferometric Synthetic Aperture Radar (InSAR) is playing an increasingly important role in the observation of coseismic surface deformation caused by earthquakes, and has been used to invert for subsurface fault structure and reveal earthquake source mechanisms. However, the mapping of complex non-planar or curved (e.g., listric-shaped) faults still remains a challenging task due to variable dips along the underground depth and the impenetrability of the deep crust. Here, we develop a set of new inversion algorithms to determine the listric fault geometry with InSAR- and GPS-observed surface deformation as the significant constraints. The fault surface with variable dip angles is discretized into consecutive sub-fault layers along the down-dip direction. A nonlinear iteration algorithm is used to minimize the objective function to determine the dip angle for each sub-fault layer. The proposed method is first tested using synthetic data to show its effectiveness for retrieval of varying fault geometry dips, and then applied to the 2008 Mw 7.9 Wenchuan earthquake that ruptured the Yingxiu-Beichuan fault for over 320 km along the southwest-northeast strike. The inversion shows that the dip angle of the seismogenic fault is up to 76° near the surface layer, and gradually decreases along the down-dip direction. A significant decrease in dip occurs within the depths of 6–15 km with a dip of 32° at a depth of 15 km. The dip angle decreases to 2° at a depth of 20 km, and finally merges with the subparallel PengGuan fault, which is basically consistent with geological investigations and seismic waveform data inversion. Using the inferred fault geometry, the slip model associated with the event is estimated. Five high-slip concentrations along the strike of the Yingxiu-Beichuan fault are recognized. The inversion misfit of InSAR data is reduced to 7.1 cm with a significant improvement compared to previous studies.