Document Type : Research Paper

Author

• Alireza Owsati

Abstract

Today, undoubtedly, the basis of the preparation of topographic maps can not be understood as independent from the use of satellite imagery, since these images provide humanity with valuable information for the preparation of maps and other information on land features used during the process of making maps. In order to prepare maps on very large scales (1: 1000 and larger) as well as on relatively small zones, it is also possible that methods that are based on measurement and interpretation of satellite images be employed rather than classic methods of surveying. In any case, even when such images are taken as bases of the creation of topographic maps, As long as the land surveying methods are not carried out to create control points, collect names and information and determine boundaries (which are integral parts of the preparation of topographic maps), classify land features that can not be determined on the images, and complete some map features that are covered by plants, buildings or shadows, these maps can not be of particular and reliable significance.

In the mapping projects, the quality that makes the map sufficiently valid is the comprehensive and useful information that is transmitted through the map to the user. In fact, 95% of the total efforts made in the process of making maps is directed toward this goal, so it is not irrelevant to mention a brief overview of the special features of topographic and thematic maps reflected in Table 1. Topographic maps and equivalent modern maps include collections of digital tantamount data that not only can be considered as valuable products in their own regard, but also as the basis for other types of thematic maps created using images from telework. In the United Kingdom alone, we find large governmental surveying agencies, including the ordnance Survey or the Directorates of overseas or Military Surveyors, which use a large number of employees to prepare topographic maps. In addition to the aforementioned companies, there are many private agencies active in the same field that seek to meet the needs and advancement of the goals of engineers, designers, architects, oil and mining companies, etc.
All these companies widely use satellite imagery to advance their intentions.