19-12-2009, 10:21 AM
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Abstract.
Precise positioning in indoor environments faces different challenges than the outdoor ones. While indoor environments are limited in size to rooms and buildings, outdoor positioning capabilities require regional or even global coverage. Secondly, the difficulty of receipting satellite signals indoors has triggered the development of high sensitive and AGNSS receivers “ with many issues remaining unsolved. Thirdly, the accuracy requirements are dissimilar between indoor and outdoor environments “ typically there is a higher demand for relative accuracy indoors. This paper should be regarded as an overview of the current and near future positioning capabilities for indoor and outdoor environments however it does not lay claim to completeness. Focus is given on various novel position systems that achieve cm-level accuracy or better which is a requirement for most geodetic applications.
Introduction
Today, total stations cover most geodetic applications for determining 3D real-time positions indoors. However, to access increased availability, various weaknesses remain inherent in total station systems such as the requirement of direct line-of-sight and manual setup of a relatively large sized and expensive instrument. This paper addresses these weaknesses and looks forward to alternative positioning methods that may enable a ËœMillimeters Everywhereâ„¢ scenario in the near future. Unfortunately, locations inside buildings, basements and tunnels remain harsh environments for precise positioning. Typical indoor environments contain multiple walls and a large number of obstacles that consist of various materials. As a result, current indoor positioning systems cannot satisfy the challenging demands for most indoor applications. This insufficiency may explain the diversity of current indoor position systems
