COREGAL developed a low cost unmanned aerial platform and service for biomass mapping will allow wide scale mapping in the Brazilian context of forest management. A first of a kind combined Position-Reflectometry Galileo receiver has been developed as main sensor for platform positioning and biomass estimation, the latter using reflected Global Navigation Satellite Systems (GNSS) signals (also called GNSS-R) that propagate through tree canopies, branches and leafs.
The concept of GNSS-R is that of a bi-static radar, where the transmitter is a GNSS satellite and where the receiver can receive both the signal coming directly from the source and the signal reflected from the Earth’s surface. In spite of the fact that the properties of GNSS signals have been optimized for navigation applications, the reflected signals contain information about the state of the reflecting surface.
High positioning accuracy (centimetre level) products are also provided on board the aerial platforms, which is challenging for remote areas where no GNSS ground support infrastructure is available as in the case of many forests in Brazil. However, Galileo AltBOC E5 signals offer unprecedented pseudorange measurement quality which can be used for high accuracy positioning
An Unmanned Aerial Vehicle (UAV) is equipped with a COREGAL receiver and optical cameras for aerial mapping and biomass estimation, enabling wide scale low-cost mapping: UAV aerial mapping is at least one order of magnitude lower cost than manned air-borne missions while GNSS-R can be seen as bi-static RADAR replacing expensive, heavy and power consuming radars. Integrating positioning and reflectometry in a single device within a UAV offers a unique value proposition where Galileo and GPS are uniquely combined for increasing the number of reflected signals and positioning quality. Furthermore, GNSS-R signal properties allow lower saturation in signal backscattering when compared to traditional RADAR systems, allowing higher sensitivity to higher biomass applicable to the Brazilin forests.
Business plan and model as well as a market survey has been developed and Legal and regulatory issues have been considered. A wide dissemination of project results has been achieved. Results have presented in several conferences, magazines and events as well as a dedicated webinar targeting Brazilian community. Project website has been updated thought the project with results and events.
Test campaigns have been performed to validate the COREGAL platform and approach with promising results, including comparison and combination with satellite-derived data to improve accuracy of local biomass maps. Due to insufficient field data, synthetic GNSS-R data had to be generated which although not replacing the final data, allowed to preform needed research work with high degree of confidence. Such maps are then converted into carbon maps allowing enhancements in carbon cycle modelling with far reaching implications. The full processing chain and methodology has been exercised allowing to demonstrate the concept as part of a service to be commercially provided, which can be expanded to other countries.
As a major outcome of COREGAL, the consortium recommends more tests to be performed on-field to consolidate results, confirm some of the assumptions and get more operational experience. This was already foreseen in the business plan, where a phase 0 would include gathering first beta users. The COREGAL solution is considered by the consortium a promising approach that is expected to enable substantial cost reduction and high accuracy biomass maps allowing accelerating the adoption of Galileo based technology in Brazil and worldwide regions with forests. The consortium is therefore committed to give next steps to continue to further implement and commercialise the concept.
