2,521 research outputs found
Localization and 3D Reconstruction of Urban Scenes Using GPS
Using off-the-shelf Global Positioning System (GPS)
units, we reconstruct buildings in 3D by exploiting the reduction
in signal to noise ratio (SNR) that occurs when
the buildings obstruct the line-of-sight between the moving
units and the orbiting satellites. We measure the size and
height of skyscrapers as well as automatically constructing
a density map representing the location of multiple buildings
in an urban landscape. If deployed on a large scale, via
a cellular service provider’s GPS-enabled mobile phones or
GPS-tracked delivery vehicles, the system could provide an
inexpensive means of continuously creating and updating
3D maps of urban environments
Visual 3-D SLAM from UAVs
The aim of the paper is to present, test and discuss the implementation of Visual SLAM techniques to images taken from Unmanned Aerial Vehicles (UAVs) outdoors, in partially structured environments. Every issue of the whole process is discussed in order to obtain more accurate localization and mapping from UAVs flights. Firstly, the issues related to the visual features of objects in the scene, their distance to the UAV, and the related image acquisition system and their calibration are evaluated for improving the whole process. Other important, considered issues are related to the image processing techniques, such as interest point detection, the matching procedure and the scaling factor. The whole system has been tested using the COLIBRI mini UAV in partially structured environments. The results that have been obtained for localization, tested against the GPS information of the flights, show that Visual SLAM delivers reliable localization and mapping that makes it suitable for some outdoors applications when flying UAVs
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