Abstract
Abstract. For some years now, UAVs (unmanned aerial vehicles) are commonly used for different mobile mapping applications, such as in the fields of surveying, mining or archeology. To improve the efficiency of these applications an automation of the flight as well as the processing of the collected data is currently aimed at. One precondition for an automated mapping with UAVs is that the georeferencing is performed directly with cm-accuracies or better. Usually, a cm-accurate direct positioning of UAVs is based on an onboard multi-sensor system, which consists of an RTK-capable (real-time kinematic) GPS (global positioning system) receiver and additional sensors (e.g. inertial sensors). In this case, the absolute positioning accuracy essentially depends on the local GPS measurement conditions. Especially during mobile mapping applications in urban areas, these conditions can be very challenging, due to a satellite shadowing, non-line-of sight receptions, signal diffraction or multipath effects. In this paper, two straightforward and easy to implement strategies will be described and analyzed, which improve the direct positioning accuracies for UAV-based mapping and surveying applications under challenging GPS measurement conditions. Based on a 3D model of the surrounding buildings and vegetation in the area of interest, a GPS geometry map is determined, which can be integrated in the flight planning process, to avoid GPS challenging environments as far as possible. If these challenging environments cannot be avoided, the GPS positioning solution is improved by using obstruction adaptive elevation masks, to mitigate systematic GPS errors in the RTK-GPS positioning. Simulations and results of field tests demonstrate the profit of both strategies.
Highlights
In recent years mobile mapping platforms, such as unmanned areal vehicles (UAVs), are more and more often used for surveying tasks with high accuracy requirements
By comparing the satellite positions and the elevation mask boundary in the skyplot of point #22, the satellites G23 and G30 can be identified as being obstructed by the right building. These satellite signals are either subject to non-line-of-sight receptions (NLOS) reception or they are diffracted at the edge of the building
In this paper two real-time capable and easy to implement strategies to improve the accuracy of the direct georeferencing of UAVs under challenging GPS measurement conditions were presented
Summary
In recent years mobile mapping platforms, such as unmanned areal vehicles (UAVs), are more and more often used for surveying tasks with high accuracy requirements. The research presented here, has been carried out in the context of a scientific project called ’Mapping on Demand’ (Klingbeil et al, 2014). The aim of this project is to enable autonomous mapping of objects, such as buildings, with an UAV, which plans its trajectory autonomously, detects and avoids obstacles and provides 3D mapping data already during the flight. The goal of the automation is to optimize the flight path in relation to the intended data acquisition, to reduce the user effort in the processing chain, to enable a real-time mapping with UAVs and to improve the accuracy of the mapping results, especially in urban environments
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
