Digital Photogrammetry at Ordnance Survey Ireland

The main activities carried out by Ordnance Survey Ireland are focused on the production and maintenance of both small and large scale topographic databases. In 1980, photogrammetric methods were extensively adopted to carry out these tasks, based on analytical procedures. A review of operating practices in 1992 led to the introduction of digital systems. The technical complexities of the installation of digital hardware and software in a production environment are reported in this paper. An expanded role for the photogrammetric department also required the acquisition of new skills by its personnel. Experience has shown that further development, based on co-operation between vendor and user, must continue in the digital field.     

The Ordnance Survey 1:50 000 Map

Abstract

The One Inch to One Mile Map, first published by the Ordnance Survey 175 years ago has been superseded by the new metric 1:50 000 series. This account describes the cartographic production stages of the new series and is a sequel to the paper by J. G. Price—Cartographic Journal, June 1975.     

Photogrammetry in the Ordnance Survey from Close to MacLeod

In the period after the First World War the Ordnance Survey was relatively slow to recognise the contribution that air survey could make to its work. In part, this was due to external constraints on budgets, which helped to stifle innovation. However, the views of the four Directors General, Close, Jack, Winterbotham and MacLeod, were to play large roles in determining the energy with which innovations were adopted. Both Close and Winterbotham were generally sceptical about the value of air survey, while Jack was well disposed, but constrained by budget limitations. In MacLeod, however, air survey was to find a convinced champion. This paper explores the roles played by the key players and how, in the late 1930s, significant advances were made.     

The role of the Ordnance Survey of Great Britain

Abstract

This paper is concerned with the future of the British national mapping agency in a society which is markedly different from that in which the Ordnance Survey Review Committee of 1979 worked. The objective is to ascertain which topographic information is needed, who should provide it, on what terms and through which mechanisms. Prior to making an attempt to answer these questions, the essential characteristics of Ordnance Survey (OS) are summarised as deduced from available documentary evidence; the changing attitudes to information as a commodity, the growing competition in British mapping and the government's stringent requirements from the Survey are also outlined as just three of the many complexities which affect OS. Building upon Smith's classic 1979 paper and subsequent experience, the rationale for government involvement in mapping is examined. It is concluded that the Survey has a continuing vital role though there are a number of steps which the OS should take in order to adapt to changing circumstances.     

The Digital National Framework and Digital Photogrammetry at Ordnance Survey

Over recent months the Ordnance Survey, Britain's national mapping agency, has changed the way in which it uses photogrammetry to update its large scales topographic database. The nature of the database itself has also changed during the same period, as the concept of a "Digital National Framework" has developed. This paper describes the Digital National Framework, the topographic data captured by Ordnance Survey within this framework and the capture methods currently used. The paper concentrates on the use of photogrammetry in the update process, describing the methods of the past, the methods currently in production, and the outlook for photogrammetry within the Ordnance Survey in future.     

Ordnance Survey Policy and Practical Implications for The Revision of Rural Mapping

During 1994 a project was initiated by Ordnance Survey to investigate the requirement for completing the multi-million pound digital revision of 1:2500 scale mapping within Great Britain. This paper, although concentrating on this scale of mapping, discusses the revision policy issues that faced Ordnance Survey and the practical implications arising from implementing the policy for its 1:2500 and 1:10 000 basic scale mapping. Use of contractors was seen as a prime requirement as the resources available within Ordnance Survey were not sufficient to implement the full revision programme. This paper discusses the background to the task and considers the range of photogrammetric options and contractual and quality procedures required for the revision of the mapping over the next few years.     

The Ordnance Survey of Northern Ireland: An Outline of its History and Present Mapping Tasks

Abstract

This explains the formation of the Ordnance Survey of Northern Ireland as a separate institution in 1921, when it took over the map series which until that time had been part of the Ordnance Survey (U. K.) responsibility. As happened with many mapping organisations, replanning and reorganisation took place after 1945; this included a triangulation for Northern Ireland to provide a basis for a new Irt"sh Grid, and the introduction of the 1:1250 scale for major urban areas.

The technical problems of reproduction and revision are then considered, and details given for each of the main series.     

The Changing Role of Ordnance Survey International With Case Studies in Trinidad, Guyana and Albania

This paper discusses the role of Ordnance Survey International as a division within Ordnance Survey and outlines the work currently being carried out world-wide. It identifies the commercial structure of the business and justifies the reasons for participation in overseas markets. The key business activities of Adviser to the United Kingdom Department for International Development, international relations, library services, training and consultancy are all described. In addition, three case studies are included to support the main text.     

测绘仪器发展的回顾与展望

测绘仪器是测量之本,伴随着测绘科学的发展,测绘仪器从早期的测绳、罗盘仪、游标经纬仪发展到目前的电子经伟仪、数字水准仪、全站仪、GPS以及各种电子专用仪器。大大推动了测绘工作向自动化、数字化、智能化方向发展。对测绘仪器的发展进行回顾与展望。     

机载激光测深的技术装备

本文介绍了机载激光测深仪的发展历史和现状及其技术原理、特点和使用范围，并简述了激光测深仪的发展趋势，仅供广大测绘工作者参考。     

三峡水利枢纽主体工程施工控制测量

介绍了采用测边三角网和GPS静态测量实施三峡工程加密控制网的应用情况,阐述了随着光电测距精度的不断提高及水电施工环境的影响,采用测边网加测距三角高程网实施控制网加密是当前行之有效的一种好方法;此外,GPS测量以其限定条件少、操作简单、高自动化的内业处理等优点为施工控制测量开辟了一条新途径。     

TCA全站仪实现测量数据的全自动化处理

将GeoBasic编译的机载应用程序上载到TCA2 0 0 3测量机器人中 ,可在一定程度上实现野外观测的自动化 ,尤其是高精度的导线 (网 )和三角网测量中具有重要的应用意义。将仪器中的数据利用LeicaSur veyOffice软件下载到计算机中 ,并以文本格式保存。自主编译的数据转换程序可将原始数据转换为平差所需要的文本数据格式 ,录入到平差软件中便可自动平差计算 ,实现了数据采集、处理的自动化。     

网络调查技术在地理调查中的应用

以地理调查为理论依据,系统论述了网络调查技术开展的技术方法、工作模式,并结合乡村规划综合信息调查,论述了网络调查技术在地理调查中的应用,对于丰富地理调查方式、创新地理调查手段、提升信息获取效率具有现实意义。     

海洋磁力测量中测线方向的选择方法

采用测线间磁异常插值精度分析了测线方向对磁测的影响;探讨了测线方向的选择方法,结合我国不同海区磁异常分布特征给出了不同海区测量时测线方向的选择详细方案.结论表明:海洋磁力测量中,测线方向对磁异常插值精度的影响不大,但是为了获得更高的磁异常插值精度,测线方向应尽量沿磁异常梯度方向布设.给出的测线方向的选择方法和我国不同海区测线方向选择详细方案可供作业人员参考.     

全站仪断面测量方法

从野外断面测量的角度出发,主要讨论全站仪在断面测量中的野外观测方法、数据处理思路以及相应的软件研制.