无人机三维倾斜摄影测量助力自然资源调查——以不动产调查为例

随着第一次地理国情普查与监测、第三次全国土地调查等重大自然资源调查类项目的实施,以无人机作为搭载平台的遥感影像获取手段在不断发展并深入应用,特别是无人机航测技术和地理信息技术的结合应用越来越紧密.本文以不动产调查为例,重点论述结合无人机三维倾斜摄影测量技术在内的测绘地理信息新手段的作业原理及应用情况,并对其优缺点进行总...     

海底AUV关键技术综述

海底海洋的观测探测,亟需大范围、长时间的观测平台。海底AUV有三大要点：适应海底机动性的结构、适应海底复杂环境的机敏运动性能、适应海底的水声通信定位技术。本文分析了海底AUV的发展与演变历程,凝练出海底AUV的关键技术难题,并相应地给出海底AUV水动力外形优化技术、海底AUV机敏运动控制技术、海底水声通信与定位导航技术、海底接驳与充电技术的解决思路。最后以碟形结构的水下直升机为例,给出了海底AUV的实践探索一例。本文将为海底AUV及其观测探测技术的发展提供指导意义。     

Using unmanned underwater vehicles as research platforms in coastal ocean studies

The advantages of using unmanned underwater vehicles in coastal ocean studies are emphasized. Two types of representative vehicles, remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV) from University of South Florida, are discussed. Two individual modular sensor packages designed and tested for these platforms and field measurement results are also presented. The bottom classification and albedo package, BCAP, provides fast and accurate estimates of bottom albedos, along with other parameters such as in-water remote sensing reflectance. The real-time ocean bottom optical topographer, ROBOT, reveals high-resolution 3-dimentional bottom topography for target identification. Field data and results from recent Coastal Benthic Optical Properties field campaign, 1999 and 2000, are presented. Advantages and limitations of these vehicles and applications of modular sensor packages are compared and discussed.     

基于无人船的水质监测及控制系统设计

针对执行水质监测任务过程中固定浮标监测站单点监测存在局限性、船载观测人员取样耗时耗力等问题,本文设计了一种搭载多点、分层自动采水取样装置的智能无人船水质监测系统,可实现目标水域的多点、分层连续水质数据测量及取样。该智能无人船具备基于快速随机树(Rapid Random Tree)算法的自主避障和快速路径规划功能,解决了现有无人船技术存在的多障碍自主路径规划难等问题。同时,本设计结合了ARM9控制芯片、M5310无线传输模块,通过可视化的显示界面和远程WEB访问的功能,大大提升了科研人员及时处理特殊情况便捷性。通过实验测试及比对分析,证明本设计具有智能高效、稳定可靠等优点,能够满足职能部门对于水质监测工作的需要。     

直升机TEM系统发展研究现状及应用前景

文章回顾了直升机TEM技术的发展历史,阐述了发展直升机TEM系统的必然性;根据国外直升机TEM系统的研制和应用现状,对直升机TEM技术的系统特点进行了论述;在综合分析的基础上,指出了我国应该发展的直升机TEM系统类型,以及在我国地质勘查中的应用前景。     

THE APPLICATION OF MINIATURE UNMANNED AERIAL VEHICLE IN 25 NOVEMBER 2016 ARKETAO MW6.6 EARTHQUAKE

In order to complete the field investigation to the 25 November 2016 Arketao M_W6.6 earthquake, ultra-low altitude remote-sensing data were obtained from miniature unmanned aerial vehicle. The surface rupture surveying has important significance for earthquake research. This paper selects the macro-epicenter of Arketao as the study area. The pictures were obtained with DJI Phantom 3 professional input into the software, the Digital Elevation Model (DEM), Digital Orthophoto Map (DOM) were acquired based on photogrammetry method using the overlapped optical remote-sensing images of UAV. Using these data, we can identify surface ruptures that have vertical dislocation. We selected six feature points and drew the elevation profile. In the elevation profile map, we chose smooth part of the surface rupture sides and obtained the trend line. A stable point in the surface rupture was selected and the abscissa of the point was taken into the equation of two straight lines. Then subtracting the results of the two equations, we can get the vertical dislocation of the surface rupture. On this basis, we chose six feature points and determined their vertical dislocation, which are between 4.4cm and 10.4cm. What's more, taking Bulungkou Xiang in Xinjiang Uygur Autonomous Region for example, we speculated some surface ruptures that have vertical dislocation. It can provide a new method for identifying surface rupture in the field. In addition, we get DEM data of the Bulunkou area where ambient conditions are very poor, by using miniature unmanned aerial vehicle and taking 255 photos. Putting those photos into the EasyUAV software, we got the area digital elevation of 2cm resolution. Comparing these data with RTK data, we summarized some practical problems and solutions in the practical operation and evaluated the accuracy of miniature unmanned aerial vehicle data. The Pearson Correlation Coefficient is 0.996 6. In terms of absolute elevation, the average result of UAV and RTK differs by 156.96m. In terms of relative elevation, the average result of UAV and RTK differs by 9.74m. Compared with the previous test of Pishan County, there is a notable divergence in the results. It shows that the data accuracy will be affected to some extent in the cold weather in high elevations. The specific impact needs further exploration.     

基于无人机遥感的黄河下游河南段河滩地植物群落多样性研究

周期性的农业活动和水沙变化已经显著改变了黄河下游河滩地的植物群落结构,快速、准确地获取河滩地的植物群落多样性信息,可以为黄河流域生态保护和恢复提供参考依据.以位于河南省新乡市原阳县朱贵村南部的黄河下游河滩地的植物群落为研究对象,采用最大似然、人工神经网络、面向对象和随机森林分类方法,利用无人机多光谱遥感影像数据,对河滩...     

基于最优路径的无人机影像辐射区域网平差

无人机遥感能够提供高时空分辨率的影像数据,拥有广泛的应用前景。辐射校正将传感器记录的数据转化为地表反射率,是无人机数据定量化应用的前提。然而无人机数据易受光照等因素的影响,导致影像间存在不同程度的辐射差异,为多张无人机影像的辐射校正带来困难。基于影像间重叠区域的信息,辐射区域网平差能够获得全局最优的辐射校正参数,降低影像间的辐射差异,因此在实现影像的辐射校正方面具有巨大潜力。但大量待求解未知参数降低了辐射校正模型的求解效率,特别是在数据量急剧增加时,该问题更为突出。基于影像重叠区辐射信息建立的最优路径很好地考虑了影像间的辐射转化关系,可有效控制误差累计,为减少辐射区域网平差中未知参数的数量提供了一种思路。因此,本文将最优路径与辐射区域网平差相结合,以降低待求解参数的数量,在保证辐射校正精度的同时提高辐射校正模型求解效率,进而提升辐射区域网平差在大数据集上的应用潜力。     

Pix4Dmapper在无人机航摄应急救灾项目中的应用研究

无人机由于其独特的航摄优势,在灾害应急处理等特殊事件中,发挥着越来越重要的作用。本文结合一次山体滑坡救灾项目,阐述了使用Pix4Dmapper软件对无人机航摄数据进行快速处理,并获取正射影像图和数字表面模型的方法,通过数据分析和评估,证明了此方法的可行性和有效性。     

Experimental Study of a Command Governor Adaptive Depth Controller for an Unmanned Underwater Vehicle

Unmanned Underwater Vehicles (UUVs) are increasingly being used in advanced applications that require them to operate in tandem with human divers and around underwater infrastructure and other vehicles. These applications require precise control of the UUVs which is challenging due to the non-linear and time varying nature of the hydrodynamic forces, presence of external disturbances, uncertainties and unexpected changes that can occur within the UUV’s operating environment. Adaptive control has been identified as a promising solution to achieve desired control within such dynamic environments. Nevertheless, adaptive control in its basic form, such as Model Reference Adaptive Control (MRAC) has a trade-off between the adaptation rate and transient performance. Even though, higher adaptation rates produce better performance they can lead to instabilities and actuator fatigue due to high frequency oscillations in the control signal. Command Governor Adaptive Control (CGAC) is a possible solution to achieve better transient performance at low adaptation rates. In this study CGAC has been experimentally validated for depth control of a UUV, which is a unique challenge due to the unavailability of full state measurement and a greater thrust requirement. These in turn leads to additional noise from state estimation, time-delays from input noise filters, higher energy expenditure and susceptibility to saturation. Experimental results show that CGAC is more robust against noise and time-delays and has lower energy expenditure and thruster saturation. In addition, CGAC offers better tracking, disturbance rejection and tolerance to partial thruster failure compared to the MRAC.