GEOGRAPHICAL POSITIONS IN MALAYA AND SIAM

Abstract

Malaya.—The geographical positions of points in the “Primary Triangulation of Malaya”, published in 1917, depend upon latitude and azimuth determinations at Bukit Asa and on the longitude of Fort Cornwallis Flagstaff, Penang, the latter being supposed to be 100° 20′ 44″.4 E. This value was obtained by Commander (later Admiral) Mostyn Field in H.M.S. Egeria 1893, by the exchange of telegraphic signals with Mr Angus Sutherland at Singapore, Old Transit Circle. The longitude, 103° 51′ 15″.75 E., accepted for Singa- pore in order to arrive at this determination of Fort Cornwallis Flagstaff, was based upon that of an Observation Spot, 103° 51′ 15″.00 E., fixed in 1881 by Lieutenant Commander Green, United States Navy, by meridian distance from the transit circle ofMadras Observatory, the corresponding longitude of the latter being taken as 80° 14′ 51″.51 E.     

GEOGRAPHICAL NAMES IN UNINHABITED REGIONS AND THE CONTROVERSY OVER THE MOUNT EVEREST MAP

Abstract

(I) The deserts of India and Baluchistan.—In the eastern half of the Great Indian Desert there are rock-outcrops projecting above the sand at in tervals averaging twenty miles; these have been landmarks for travellers for centuries, and consequently they all have native names. In the western desert there are no outcrops and no objects to name; but the desert nomads and the camel-breeders do have names for vague undefined areas, which seem to move as the sandhills move. The rock-outcrops in Baluchistan are larger and more numerous, and many are consequently without Baluchi names. Nothing would have been gained from inventing names; names are for use, not for show, and the desert people know their own requirements. It is better on a map to limit the nomenclature to the names that have been born of the people and that have stood the test of time than to supplement them with fictitious names. Survey stations on unnamed hills are therefore generally designated by symbols such as B45.     

DANISH EXPERIENCES IN GEOGRAPHICAL INFORMATION SYSTEMS

Many organisations are today working at establishing information systems and quite a few exist already. When it comes to geographical information systems (GIS), the geographical reference will soon be solved. All new mapping in Denmark is digital and in 1992–93 the country will have complete coverage. In addition, many public registers are already computerised. A lot of other information sources, like utility networks, are still to be converted. As these developments are in the hands of many different organisations, both private and governmental, this paper will deal with the efforts made to co-ordinate various activities in a strongly competitive world. As there is a distinct difference between large scale and small scale GIS activities, this paper will deal mainly with large scale GIS, as should be the case when considering GIS and photogrammetry.     

GEOGRAPHICAL INFORMATION SYSTEMS AND PHOTOGRAMMETRY ORGANISATIONAL ISSUES

This paper was presented at the 1990 Thompson Symposium. It distinguishes between geographical information systems (GIS) as a set of hardware and software tools and the institutional problems that arise when implementing GIS in an organisational environment. It examines issues such as data quality, that arise when treating information as a corporate resource, as well as the legal, economic and social constraints on the use of data.     

秩亏Gauss—Markov模型参数的有偏估计

本文讨论秩亏自由网平差中系数阵存在严重复共线性时参数的有偏估计问题。通过引入秩亏Ｇａｕｓｓ－Ｍａｒｋｏｖ模型的典则形式，将秩亏Ｇａｕｓｓ－Ｍａｒｋｏｖ模型参数的有偏估计问题转化为满秩Ｇａｕｓｓ－Ｍａｒｋｏｖ模型参数的有偏估计问题，由此提出了未知参数的一个有偏估计类，并讨论了它的优良性质；通过适当选择变换矩阵，构造了许多很有价值的有偏估计，其中包含的偏参数都能通过满秩Ｇａｕｓｓ－Ｍａｒｋｏｖ模型确定     

面向对象的虚拟地理资讯平台的设计与实现

本文采用面向对象的技术，探讨了基于VR技术的地理资讯系统的设计平台和体系结构，结合三维场景中对象模型、资源和信息数据，提出了面向对象地理资讯系统平台的解决方案，并在虚拟平台上实现了虚拟校园的规划和设计，以及在虚拟校园中漫游和面向三维对象的查询。     

NOTES ON THE FIXING OF ASTRONOMICAL POSITIONS

Abstract

Except in the sphere of geodetic surveys, there seems to be a lamentable lack of helpful publications for the field surveyor. Comparative methods and standards of accuracy to be expected according to the type of instrument used are rarely to be found in print, and that is the only excuse for the following critical summary of some observations made during the winter of 1933–4.     

对发展四川省基础地理信息产业的若干思考与建议

本文阐述了发展基础地理信息产业对发展四川省信息产业的重要意义，分析了四川省基础地理信息产业发展的现状，并就发展基础地理倩息产业提出了若干建议．     

动态地理现象的地图表示

就制图中表示动态现象的表达方法进行了总结,并指出应结合具体条件和用图目的来选择合适的表达方式.     

INPUT OF PHOTOGRAMMETRIC DATA TO GEOGRAPHICAL INFORMATION SYSTEMS

Photogrammetric data form a major input to geographical information systems. The evolution of digital output from stereoplotters is traced, from hardwired devices producing co-ordinates or hardcopy to direct links with sophisticated GIS software. The view that the transfer and reformatting processes are simple and straightforward is examined and it is suggested that considerable labelling and structuring of data are necessary before the full power and flexibility of GISs can be harnessed. Hence it is argued that on line database creation by means of stereoplotter/GIS interfaces may not be the most cost effective procedure.     

预生成思想在地理信息服务中的应用研究

从瓦片地图、栅格索引、公交换乘三方面阐述了预生成思想在地理信息服务中的应用,论证了预生成思想在提高地理信息系统的响应速度方面具有重大的意义。     

旅游地理信息系统的研究

针对当前旅游地理信息系统的发展状况,提出如何在旅游领域拓宽GIS的应用范围并提高其应用水平。介绍了旅游地理信息系统的结构、功能,分析了系统设计中应注意的几个问题,展望了旅游地理信息系统与虚拟现实技术、网络技术等新技术的发展前景。     

大金湖国家地质公园地理信息系统的设计

介绍了应用地理信息系统技术,对福建大金湖国家地质公园的资源环境信息进行采集、管理和分析,并以图文和声像形式综合展示系统处理信息的结果,使大金湖国家地质公园的管理工作达到科学化、规范化和标准化,为申报世界地质公园提供高水平的技术支持     

SURVEYING AND MAPPING IN CANADA

Abstract

In a country of the size of Canada, the third largest in the world, comprising more than three and a half million square miles and extending through eighty degrees in longitude and a range of latitude from 42° to the North Pole, there is every variety of topography. There are the characteristic accidented regions of the Maritime Provinces and the lower St. Lawrence, vast treeless areas in the Canadian West, and park lands spreading out northwards to merge eventually into the forests, which again give way to the open northern plains that lie towards the Arctic. There are level fertile expanses, hilly areas, marshes, rocky regions of low relief, and localities that display mountainous scenery rivalling anything that exists in other parts of the world. In some places industry has taken its firm foothold with a consequent density of population. In the agricultural areas the population spreads itself out more thinly.     

PHOTOGRAMMETRY IN SCIENCE AND TECHNOLOGY

An individual view is provided of the function of the art and science of photogrammetry, over the whole of the history of attempts to make measurements from optical observations. The predominating influence, in past years, of the need for mapping from air photographs is compared with the prospect that increasing demands for similar facilities in close range measurement, for application in fields such as mechanical engineering, medicine and architecture, may soon be seen to give further encouragement to the development of the subject. The author makes use of illustrations from his experience to point out simple cases where the potential of photogrammetric techniques, in the wider sense, has not been appreciated.