原型黄河航测遥感观测体系关键技术研究

1、原型黄河航测遥感观测体系关键技术研究高庆方（黄河勘测规划设计有限公司测绘信息工程院 河南郑州 450045）【摘 要】介绍了摄影测量与遥感的技术原理和主要任务，论述了航测遥感技术的最新发展和关键技术。航测遥感技术的应用，实现了黄河空间信息的快速、准确获取，从而构建了原型黄河航测遥感观测体系。论述了原型黄河航测遥感观测体系在黄河下游防洪、小北干流放淤、水土保持、河势监测等业务工作中的应用。【关键词】 摄影测量 遥感 原型黄河 一、 摄影测量与遥感技术的发展摄影测量与遥感是通过空间对地观测获取地表影像，利用影像研究和确定目标物的空间位置、几何特征、形状、大小、性质和相互关系的一门科学与技术。摄影测

2、量与遥感的区别在于影像获取方式不同，摄影测量是利用飞机上的航摄仪对地面摄影成像，遥感通常是指利用卫星上的传感器对地面观测成像。摄影测量与遥感的主要任务是测制各种比例尺地形图、建立地形数据库、资源调查、环境监测，其特点是在影像上进行测量与解译，无需接触目标物本身，因而很少受自然和地理条件限制。航空影像、遥感影像是客观物体或目标的真实反映，信息丰富，可以从中获取大量几何信息和属性信息。在水利工程规划、设计、建设、管理等工作中，摄影测量与遥感是进行空间定位、获取地理信息和属性信息的主要技术手段，发挥着不可替代的作用。摄影测量经历了模拟摄影测量、解析摄影测量到目前的数字摄影测量三个发展阶段。测绘产品从

3、单一的纸质线划地图转变多种数字产品，如数字线划地图、数字高程模型、数字正射影像地图等。随着空间科学、信息科学和计算机技术的飞速发展，摄影测量与遥感技术也进入了一个新时代：数字摄影测量采用的航空传感器由光学传感器到数字传感器，影像类型由光学影像转变为多光谱数字影像，基于航空导航定位测量系统和差分卫星定位系统（IMU/DGPS）的新型数字航空摄影技术的应用，提高了数字摄影测量的作业效率和成果质量，缩短了地理数据采集与更新的周期。利用GPS辅助航空摄影，实现无地面控制点或少地面控制点的测量，摆脱繁重的野外控制测量工作。机载激光雷达（LIDAR）空间测量技术的研究和应用，使得实时、动态、快速获取地形信

4、息成为可能。数字摄影测量与地理信息系统的结合，促进了测绘生产过程的数字化和自动化，提高了地理数据采集的效率和精度，缩短了地理数据库的更新周期，能够保证地理数据库的现势性。遥感技术正朝向多种传感器、多级分辨率、多频谱、多时相的信息获取和快速实时的智能化信息处理的方向发展，高分辨率卫星摄影系统、高分辨率成象光谱仪、合成孔径雷达等新型传感器及其影像信息处理系统日益受到重视。遥感影像解译实现自动化或半自动化，利用高分辨率卫星影像获取大比例尺地理数据，基本保障地理信息的快速获取和更新。一个多种分辨率、多种传感器的遥感对地观测系统业已形成。二、 原型黄河航测遥感观测体系的建立黄河治理开发的终极目标是维持黄

5、河健康生命，原型黄河、数字黄河、模型黄河“三条黄河”建设是实现这一目标的主要技术手段。作为数字黄河、模型黄河基础平台的海量黄河地理数据，主要通过摄影测量与遥感技术获取。因此，原型黄河航测遥感体系的建立，对于“三条黄河”建设具有非常重要的意义。黄河勘测规划设计有限公司测绘信息工程院始建于1933年，是黄河流域专业测绘机构，肩负黄河流域基础测绘、水利水电工程测绘以及黄河基础地理信息系统建设任务。人民治黄以来，经过一代又一代黄河测绘人的不懈努力，通过对原型黄河的不断观测，建立了黄河流域平面和高程定位基准，采用航测技术测绘了黄河流域多种比例尺地形图，完成了水利水电工程测绘，为三门峡、小浪底等水利枢纽工

6、程建设提供了准确可靠的地理信息支持。随着改革开放和经济建设的蓬勃发展、信息化技术的发展应用，面对黄河治理开发新的形势和任务，各应用部门对测绘产品的需求结构发生了很大变化，不仅需要提供传统的测绘产品，而且需要提供多样化的测绘信息产品和高新技术服务。根据技术发展和应用需求，测绘信息工程院先后开展了数字化制图、解析摄影测量、数字摄影测量、遥感（RS）、全球定位系统（GPS）、地理信息系统（GIS）等方面的研究和应用。以GPS、GIS、RS “3S”高新技术为依托的原型黄河观测体系逐步建立和完善，主要体现在以下几个方面：（1）经过模拟摄影测量、解析摄影测量到数字摄影测量的发展，测绘信息工程院建立了完整

7、的数字摄影测量与遥感作业体系，包括全数字摄影测量工作站、高精度航片扫描仪、遥感影像处理系统、数字产品编辑与建库系统等仪器设备和软件，为原型黄河观测提供了前提。（2）通过对全数字摄影测量系统技术原理、作业方法、精度指标等技术性能的应用研究，编制了全数字摄影测量系统作业技术规程，对各工序作业方法、精度指标、产品形式等做出详细规范，确保了作业精度和产品质量。通过对地理信息自然规律、表达方式与应用需求的研究，编制了黄河基础地理信息系列标准，作为数字黄河工程标准发布实施，规范了黄河基础地理数据库建设与应用。（3）通过对遥感影像处理系统的应用研究，制定了遥感影像处理作业流程，包括影像校正配准、影像合成、影

8、像融合、影像图编制等内容，使遥感影像处理程序化；通过对多种类遥感影像解译的研究，在外业样方调查的基础上，建立了多种遥感影像解译模型，为实现遥感影像的自动解译提供条件。（4）长期规模化的航测遥感生产，锻炼和培养了一批专业技术人员，他们敬业爱岗，责任心强，理论知识扎实，作业经验丰富，能够把握航测遥感的最新技术和发展方向，是原型黄河观测体系的人力资源保障。与“3S”技术相结合的航测遥感观测体系，实现了黄河基础地理数据的快速采集与建库。在全球信息化的今天，地理信息为其它各种信息提供了空间载体。三、 关键技术研究（1） GPS航空摄影测量技术航空摄影测量的一个核心问题是恢复摄影光束。为了精确恢复摄影瞬间

9、的光束，往往需要在地面上布设足够多的高精度控制点，通过严密而复杂的计算，反算出摄影瞬间飞机的姿态与位置，从而达到恢复摄影光束的目的。这种方法对野外控制点的密度、精度要求很高，在某些特殊地区实现非常困难，并且极大地影响了成图的周期及质量。因此直接获取摄影光束（像片）的外方位元素一直是摄影测量工作者不懈追求的目标。GPS全球定位系统的发展和应用，使得直接获取像片外方位元素成为可能。利用安装于飞机上与航摄仪相连接的机载动态GPS接收机配合惯性测量系统IMU，和设在地面上一个或多个基准站GPS接收机同步观测，获取航空摄影瞬间摄站的三维坐标，采用一定的数学模型和算法，整体确定像片外方位元素。GPS航空摄

10、影测量技术能够大幅度减少航测外业控制测量这一艰苦、繁重的工作，极大降低劳动强度，缩短航测成图的周期，将航空摄影测量的精确、快速的优势发挥出来。（2） 数码航空摄影测量技术常规航空摄影采用的是光学照相机，获取的是光学影像，需要对底片进行冲洗、扫描，后处理工作繁重。数码航空摄影采用数字传感器，获取的是数字影像，影像清晰、分辨率高且一次摄影可以同时获取灰度、彩红外、真彩色等多种影像。由于数码影像与光学影像成像的几何原理不同，像幅大小差别较大，采用数码航空摄影测量，关键是研究测量精度问题。通过理论分析与实际验证，确定合理的像片控制点布设和测量方案，使数字空中三角测量精度满足成图要求。研究制定采用数码影

11、像进行数字线划地图（DLG）、数字高程模型（DEM）、数字正射影像地图（DOM）“3D”产品生产的作业工艺与作业流程，确定各项限差与精度指标。（3） 高分辨率卫星遥感影像的应用卫星遥感技术发展迅猛，遥感的方式多种多样，遥感影像的分辨率在不断提高。不同区域、不同时相、不同传感器特征的遥感影像构成的真实世界影像模型为遥感应用提供了广阔的影像空间，利用高分辨率遥感影像建立原型黄河遥感观测体系已成为可能。目前，常用的高分辨率遥感影像有IKONOS影像，空间分辨率为1m，Quickbird影像，空间分辨率为0.61m。利用高分辨率遥感影像采集黄河河道地理信息、河势信息、堤防工程信息，制作数字正射影像地图

12、，更新基础地理数据库，为各业务部门提供准确可靠、现势性强的地理信息支持。遥感应用关键技术在于遥感影像的平面、高程定位精度控制，遥感影像解译实现人工干预下的半自动化，提高遥感影像对原型黄河的观测效率。四、 航测遥感观测体系的应用原型黄河航测遥感观测体系在黄河下游防洪、小北干流放淤、水土保持、河势监测等工作中发挥了重大作用。航测遥感技术应用于黄河下游防洪。黄河下游河道为著名的“地上悬河”，现行河床一般高出背河地面46m。河道上宽下窄，河南河段最宽达24km，山东河段最窄处仅275m，排洪能力上大下小。河势游荡多变，主流摆动频繁。为满足黄河下游防洪、河道整治、堤防与滞洪区工程建设、数学模型分析、物理

13、模型试验、河道冲淤变化分析，以及数字黄河工程建设等工作的需要，测绘信息工程院采用航空摄影测量技术施测了1:10000比例尺黄河下游河道地形图。黄河下游河道地形图测绘，由于采用了航测成图新技术和新工艺，严格执行水利水电工程测量规范，保证了测图精度，确保了产品质量。与采用国家标准测绘的相同比例尺地形图相比，高程测量精度比国家标准高出一倍，并且水利专题要素表示更加详细。航测遥感技术应用于黄河小北干流放淤。黄河的问题根源在于泥沙。黄河小北干流放淤“淤粗排细”是黄河泥沙治理的有效途径之一。为满足黄河小北干流放淤试验、河道整治、堤防建设等工作的需要，测绘信息工程院采用航测技术，施测了该区1:10000比例

14、尺河道地形图。本次作业以水利水电工程测量规范为依据，采用全球定位系统（GPS）进行全测区平面基本控制测量，采用自动安平水准仪进行高程控制测量，采用全数字摄影测量系统进行数据采集，测量成果具有精度高、地物、地貌、水利工程表示详细等特点。航测遥感技术应用于黄河流域水土保持。黄河流域尤其是黄土高原地区水土流失严重，是黄河问题的症结所在。为查清黄河流域水土流失现状、土壤侵蚀类型、侵蚀强度、侵蚀面积、位置分布、水土保持治理措施及人为新增水土流失情况，及时准确地掌握水土保持发展动态，为黄河流域水土保持决策规划提供依据，黄河水利委员会开展了黄河流域水土保持遥感普查工作。遥感普查运用遥感手段，以陆地卫星TM影

15、像数据为主要信息源，采用计算机辅助解译，完成土壤侵蚀现状普查，并建立土壤侵蚀数据库。遥感技术用于水土保持，技术方法先进，成果信息丰富，精度高，质量可靠。同时，便于成果应用，实现数据资源共享。航测遥感技术应用于黄河下游河势监测。黄河防汛的重点在下游。将遥感技术用于河势监测，能够快速获取河势信息，及时反应河势变化，具有精度高、速度快等特点。测绘信息工程院采用汛前、汛后成像清晰的TM卫星影像，汛期雷达影像，分别提取汛前、汛期、汛后黄河水边线，分析黄河河势，监测河势变化，并开展了TM影像、雷达影像处理和解译研究，从而解译了黄河水边线，确定了黄河河势，编制了河势图，为黄河防汛、决策提供参考。原型黄河航测

16、遥感观测体系的建立与应用，构建了原型黄河地理空间观测网络，实现了黄河空间信息的快速、准确获取，能够及时为黄河治理开发有关专业、为数字黄河工程建设提供基础地理信息支持，对于实现黄河治理开发信息化，维持黄河健康生命具有重要意义。Research on the Key Technology in the Aerial Survey and Remote Sensing Observation System of the Prototype Yellow RiverGao Qingfang(Institute of Mapping Information Engineering, YREC, Zhen

17、gzhou, China, 450045)Abstracts: In this article, the technical principle and primary task of photogrammetry and remote sensing are first introduced. And then, the author presents the newest development and the key technologies of photogrammetry and remote sensing. The applications of photogrammetry

18、and remote sensing realized the quick and accurate acquisition of the Yellow Rivers spatial information. Based on photogrammetry and remote sensing, the Aerial Survey and Remote Sensing Observation System of the Prototype Yellow River are constructed. This system can apply in the lower Yellow Rivers

19、 flood control, the lower north main-stem of Yellow Rivers warping, soil and water conservation and river monitoring. These applications are particularly discussed at the end of this article.Keywords: photogrammetry, remote sensing, the Prototype Yellow River1 Development of Photogrammetry and Remot

20、e SensingPhotogrammetry and Remote Sensing，capturing the images of land surface through the observation on ground, is a subject or technology studying a object and making sure its spatial position, geometrical characteristics, shape, size, nature as well as the relationship between different objects

21、. Photogrammetry and Remote Sensing differs in the method to acquire images. Photogrammetry obtains ground images through the aerophotographical camera in airplanes, while Remote Sensing through the sensor in satellites.The main tasks of photogrammetry and Remote Sensing are producing topographic ma

22、ps of different scales, constructing topographic databases, resource investigation and environmental monitoring. It can interpret the objects from images without contacting the true objects. So, it is less often constrained by the natural and geographical conditions. Aerial images and remote sensing

23、 images, containing abundant information, are the real reflection of actual objects or targets. From them we can attain plenty of spatial information and non-spatial information. Photogrammetry and Remote Sensing is the main technical means for spatial positioning and information (include geographic

24、al information and attribute information) acquisition and it plays an irreplaceable role in the planning, designing, construction, management of water projects. Photogrammetry have experienced three periods: analog photogrammetry, analytical photogrammetry and digital photogrammetry, whereas the map

25、ping products develop from paper line graph to various digital ones, such as digital line graph (DLG), digital elevation model (DEM), digital orthophoto map (DOM), etc. With the quick development of spatial science, information science and computer, photogrammetry and Remote Sensing is pushed into a

26、 new period: The aerial sensor used by digital photogrammetry develops from the optical sensor to the digital sensor. Accordingly, the images vary from optical images to multi-spectrum digital images. Based on the new-type digital photogrammetry technologies-IMU and DGPS, the task efficiency and pro

27、duct quality has been much improved. At the same time, the time for acquiring and updating geographical data is greatly shortened. The application of GPS(Global Positioning System) in aerial photography helps us conveniently measure the land control points and get rid of the heavy work for getting c

28、ontrol points information in the field. After using the airborne laser radar (LIDAR) for spatial measure, it is possible for us to quickly obtain real-time, dynamic topographic information. The integration of digital photogrammetry and geographical information system (GIS) facilitates the digitaliza

29、tion and automatization of mapping production, improves the efficiency and precision of spatial data acquisition, shortens the update cycle of geographical database, and ensures the real-time property of geographical database. Remote sensing technology are advancing forward the direction of acquirin

30、g multi-sensor, multi-resolution, multi-spectrum, multi-time information and quickly, intellectually processing real-time information. High-resolution satellite photograph system, high-resolution imaging spectrograph, Synthetic Aperture Radar and other new-type sensors and image processing systems a

31、re getting much more attention. The automation and semi-automation of interpreting remote sensing images and the acquisition of large scale geographical data from high-resolution images has made it possible to quickly acquire and update geographical information. At present, a remote sensing ground o

32、bservation system with various resolutions and various sensors has come into being. 2 Construction of the Aerial Survey and Remote Sensing Observation System of the Prototype Yellow RiverThe ultimate aim of Yellow Rivers development is to keep the healthy life of Yellow River. Construction of “Three

33、 Yellow Rivers” (prototype Yellow River, digital Yellow River and model Yellow River) is a main technology means to realize the above-said aim. The Geographical data of Yellow River, as the fundamental platform of digital Yellow River and model Yellow River, is mainly acquired by photogrammetry and

34、remote sensing. Thereby, construction of the Aerial Survey and Remote Sensing Observation System of the Prototype Yellow River is of great significance for the realization of “Three Yellow Rivers”.Institute of Mapping Information Engineering of Yellow River Engineering Consulting Co., Ltd, built in

35、1933, is a professional mapping department. And it takes charge of the basic mapping of Yellow River basin, mapping of water conservancy and hydroelectric power engineering and construction of Yellow River fundamental geographical information system. Since human being began to father Yellow River, a

36、fter the incessant efforts of mapping people and the perpetual observation on the Yellow River, plane datum and elevation positioning datum of the Yellow River basin have been built. By using aerial survey technology, various scales topographic maps of the Yellow River basin have been completed. And

37、 it also helps to finish the mapping of many water conservancy and hydroelectric power engineering. These mapping results have provided real-time and reliable geographical information for the construction of Sanmenxia Water Control Project, Xiaolangdi Water Control Project and other water control pr

38、ojects. With the quick development of reform opening and economic construction, as well as the widely application of information technology, the Yellow River development is facing much more new policies and tasks. As the same time, every departments demands for mapping products changes a lot. Not on

39、ly the traditional mapping product is required, but also diverse mapping information products, as well as high and new technological service are required. According to the needs of technology development and application, Institute of Mapping Information Engineering of YREC have successively done som

40、e research on many respects, such as digital cartography, analytical photogrammetry, digital photogrammetry, RS, GPS and GIS. Depending on the technology of “3s” (GPS, RS and GIS), the Observation System of Prototype Yellow River is step by step built and completed. It is mainly manifested in the fo

41、llowing respects:(1) After the development from analog photogrammetry, analytical photogrammetry to digital photogrammetry, Institute of Mapping Information Engineering of YREC has built a integrated system of photogrammetry and remote sensing, which includes digital photogrammetry work station, hig

42、h-precision aerial photo scanner, remote sensing image processing system, digital products editing & database building system and other instruments and soft wares. And they make it possible to observe the prototype Yellow River.(2) After study on the technological principle, operation methods, preci

43、sion indicators of digital photogrammetry systems, the implementation specification for the digital photogrammetry system is complied. This specification unifies operation methods, precision indicators and product styles, ensuring the higher precision and product quality. Based on the research of th

44、e natural laws, expression modes and application demands of geographical information, Institute of Mapping Information Engineering of YREC has drawn up series of standards for the Yellow Rivers fundamental geographical information. These standards have been issued and implemented as the standards fo

45、r the Yellow River engineering and they normalize the construction and application of Yellow River fundamental geography database. (3) Through studying on the application of remote sensing image processing system, we have formulated the remote sensing image processing workflow, including image recti

46、fication, image matching, image synthesis, image fusion, image map compilation, etc. And the workflow makes the remote sensing image processing procedural. After interpreting many kinds of remote sensing images and investigating the field samplings, we have established many remote sensing image inte

47、rpretation models, making the automatic interpretation of remote sensing image possible.(4) The long-term and scaled production of aerial survey and remote sensing has trained a group of specialized personnel. They love their jobs and have strong responsibility senses, solid theoretical knowledge as

48、 well as rich work experiences. Moreover, they can grasp the newest technology and development direction of aerial survey and remote sensing. They are main human resources of the prototype Yellow River observation system.Joining with 3S, the Aerial Survey and Remote Sensing Observation System have r

49、ealized the quick acquisition and database building of Yellow Rivers fundamental geographical data. In the society of global informatization, geographical information has supplied spatial carriers to many kinds of information.3 Research on key technologies(1) GPS Aerial Photogrammetry TechniqueOne c

50、ore problem of aerial photogrammetry is the resumption of photographic beam. In order to accurately restore the beams of photographing twinkling, a sufficient number of high-precision control points must be laid on the ground. Through strict and complex calculations, the airplanes posture and positi

51、on can be deducted so as to restore the beam of instant photographing. This method needs control points with high density and precision. In some special areas it is very difficult to fit the requirement, which greatly influences the aerial imaging cycle and quality. Therefore, direct access to the e

52、xterior orientation elements of photographic beams has always been the goal that photogrammetry workers pursue at all times. The development and application of GPS makes it possible to directly acquire the exterior orientation elements from photographs. By the synchronical observation of the onboard

53、 dynamic GPS receiver installed in airplanes, the Inertial Measurement System (IMU) and one or more basis station GPS receivers, we can obtain the 3D coordinates of photography stations when photographing. By some mathematical models and algorithms, the exterior orientation elements of photographs c

54、an be all worked out. GPS aerial photogrammetry technique greatly reduces the hard and arduous work of field control measurement and the labor intensity. Also, the cycle of aerophotogrammetry mapping is shortened and the advantages that aerial photogrammetry can precisely and quickly position is muc

55、h exerted.(2) Digital Aerial Photogrammetry TechniqueThe optical camera is often used for aerial photography. What it acquired is optical images. The negatives need flushing and scanning. The post-processing work is very heavy. Digital aerial photography with digital sensors can acquire digital imag

56、es which are of great clarity and higher resolution. Whats more, we can obtain many images at a time, such as gray images, color infrared images and true color images. Owning to the different geometric principles of digital imaging and optical imaging, image rates greatly vary in size. The key probl

57、em in aerial photogrammetry is the problem of measurement precision. So, we should through theoretical analysis and practical tests to determine the reasonable setting of photograph control points and the measurement planning so as to make the digital aerial triangulation measurement precision meet

58、mapping requirements. In order to determine the limited errors and accuracy indicators, it is also necessary to study and formulate the work method and work flow to produce the 3D productsDigital Line Graph (DLG), Digital Elevation Models (DEM) and Digital Orthophoto maps (DOM). (3) Applications of

59、high-resolution remote sensing imagesWith the rapid development of satellite remote sensing technology, remote sensing ways are various and resolution of remote sensing images is getting higher and higher. The image models of the true world including remote sensing images of different region, different period and different sensor provide remote sensing application a broad image space