A new point of view for surveyors
Geo-information is a fundamental infrastructure of any modern society, with many other infrastructures and services depending on it. However, it is also expensive to create and update. As a result, European, national and local government agencies must balance a growing demand for high-resolution, up-to-date geo-information against decreasing budgets. The EU-funded MAPKITE project responds to this market need by combining terrestrial mobile mapping systems (TMMS) with Unmanned Aerial System (UAS) mapping capabilities. The project aims to build a tandem terrestrial vehicle (TV) and unmanned aircraft (UA) equipped with remote sensing instruments that cooperate in collecting geo-data. The system integrates GNSS capabilities into drones and proposes a novel geo-data post-processing concept to provide surveyors with an end-to-end solution for 3D high-resolution corridor mapping. ‘While terrestrial mobile mapping systems are becoming a standard surveying tool, their use is restricted due to their limited and insufficient view from the ground,’ says project coordinator Pere Molina. ‘On the technology side, mapping of small areas via small unmanned aircraft has become a reality, with many of the big geomatic technology companies already including UAS systems in their product portfolios.’ A tandem solution MAPKITE includes both aerial and terrestrial components. The aerial component consists of a UA equipped with remote sensing instruments and a navigation guidance and control system. The terrestrial component consists of a human-operated TV that is equipped with remote sensing instruments and a TMMS. This tandem system operates with the TV, computing a real-time trajectory by means of its real-time navigation system. By doing so, a set of waypoints are generated as route inputs for the UA by converting terrestrial navigation (time, position, velocity and attitude parameters) into UA time and space commands. This process produces a virtual tether by which the UA always follows the vehicle. As the UA follows the vehicle at a constant flying height, both can simultaneously collect geodata. This is then post-processed via an orientation-calibration concept, resulting in the delivery of high-resolution, oriented-calibrated and integrated images of corridors and their surrounding environment. GNSS enhanced MAPKITE’s combination of both ground and aerial based surveying systems provides users with an integrated and powerful solution. To accomplish this, the project fully exploits such GNSS technology as EGNOS and Galileo. EGNOS, the European Geostationary Navigation Overlay Service, is Europe’s regional satellite-based augmentation system (SBAS). Galileo, on the other hand, is Europe’s GNSS programme, providing improved positioning and timing information. ‘We propose brand new ways of acquiring geo-data and processing it in order to derive geo-information that would not make sense without GNSS,’ explains Molina. ‘We also highlight the critical role of GNSS timing, due to the need to synchronise the TV’s trajectory solution to the central time of exposure of the UA remote sensing instruments.’ A game changer Due to its operational simplicity and cost savings, MAPKITE is set to be a game changer. For example, surveyors can cut costs by eliminating the need to independently operate terrestrial and aerial systems. ‘Above all, MAPKITE can lower surveying budgets by means of its Kinematic Ground Control Points (KGCPs), which are obtained directly from the TMMS navigation solution, entailing the elimination of expensive traditional Ground Control Points (GCPs),’ says Molina. ‘In short, the longer the corridor mapping mission, the higher savings are obtained with MAPKITE while keeping similar accuracy results.’
Keywords
MAPKITE, Galileo, EGNOS, GNSS, surveyors, 3D high-resolution corridor mapping, UAS, TMMS