Articles in the Articles Category
In the aftermath of the terrorist attacks on New York and Washington, finding people and bodies in the rubble was of utmost importance. This task was directed at finding location bearing devices incorporated in commonplace instruments such as mobile phones, personal digital assistants (PDAs) and electronic pagers. By polling these devices electronically using a system of triangulation points it was thought that persons and bodies could be found. Polling is simply sending electronic impulses to receivers to ascertain where these devices are located. However, and sadly, such devices have a limited range and may have no effect if buried in more than a meter of rubble. Also, some such devices incorporate global positioning systems (GPS) and these require access to the sky and to the constellation of satellites orbiting the Earth. Even the sniffer dogs gave up this mammoth task.
The past two decades have seen extraordinary growth in the demand for geo-spatial data. This demand has numerous sources and takes many forms; however, the net effect is an ever-increasing thirst for data that is more accurate, has higher density, is produced more rapidly, and is acquired less expensively. Unfortunately, traditional techniques for collecting spatial data, such as conventional surveying techniques, point-wise GPS, or aerial photogrammetry, have difficulties satisfying many of the new data collection requisites. Conventional surveying or point-wise GPS are, for instance, poorly suited for the rapid and inexpensive collection of data over large areas. Traditional aerial photogrammetry, while satisfying these needs, is disadvantaged by the requirement to establish moderately dense and expensive ground control.
The main purpose of an Aeronautical Chart is to contribute to the safety, regularity and efficiency of International Air Navigation. The increasing speed and operating altitude of modern aeroplanes, coupled with increasing congestion of air traffic necessitate availability of precise and up-to-date charts. This can be achieved by having an efficient system of Aeronautical Chart production.
31st International Symposium on Remote Sensing of Environment
20 – 24 June, Saint Petersburg, Russia
8th United Nations Regional Cartographic …