Hyperspectral Remote Sensing: A Key Pillar of Earth Observation Cooperation for Capacity Building Among European Space Agencies

Kurzfassung

Hyperspectral (HS) remote sensing is a well-established Earth Observation (EO) domain, which has matured over the last 40 years by means of various airborne (AIS, AVIRIS, CASI, HyMAP) and space borne instruments (Hyperion, CHRIS). Due to a number of current (e.g. DESIS, PRISMA, EnMAP) and upcoming (e.g. CHIME) HS sensors and missions, its relevance over the next decade is expected to increase even further. Launched by the National Aeronautics and Space Administration (NASA) in 2000, Earth Observing-1 (EO-1) was the first non-military satellite mission equipped with a HS instrument called Hyperion. The instrument acquired 220 spectral bands (30 m spatial resolution) in the visible-near-infrared (VNIR) and shortwave-infrared (SWIR) spectrum. Next, the Compact High Resolution Imaging Spectrometer (CHRIS) on board of Project for On-Board Autonomy-1 (PROBA-1) was launched by the European Space Agency (ESA) in 2001. Onboard of a scientific mission, CHRIS represented the second hyperspectral spaceborne instrument. Currently operational, the German Aerospace Center (DLR)’s Earth Sensing Imaging Spectrometer (DESIS), the Italian Space Agency (ASI)’s PRecursore IperSpettrale della Missione Applicativa /Hyperspectral Precursor of the Application Mission (PRISMA) and the DLR’s Environmental Mapping and Analysis Program (EnMAP) are advanced hyperspectral missions that acquire data across more than 200 spectral bands, with a spatial resolution of 30 m. The first Tanager satellite was launched this year (2024) by PLANET private company. Future missions are already planned, including the Copernicus Hyperspectral Imaging Mission for the Environment (CHIME) that represents one of the Copernicus Sentinel Expansion Missions (planned for launch by ESA in 2028) and the Surface Biology and Geology (SBG) which will be launched by NASA at the end of 2028 and encompasses an ASI-JPL cooperation. In this lively and evolving upstream context by which an increasing amount of HS imagery is disseminated across the international science and commercial community and, in near future, much more abundant data flow is expected, more than ever it is of paramount importance that investments are made to create a distributed network of scientific (researchers and academia groups) and commercial (developers, SMEs and geospatial services companies) users capable of analyzing these data, also through novel processing algorithms, testing of prototype products workflows and delivery of application products and services. The applications that can be developed based on HS satellite data are manifold, including (but not limited to) natural resources management, sustainable agriculture and food security (food nutrition and nutrition quality, sustainable use of nutrients and water, soil degradation and soil properties), raw materials (exploration and mining, mining environmental monitoring), biodiversity and ecosystem sustainability, forestry, coastal and inland waters (phytoplankton composition, harmful algae species), environmental degradation (methane monitoring, hazardous materials: oil spills, mine waste, pollutants, plastics) and hazards (landslides, volcanos, floods, droughts, etc.), hydrology, urban surface materials, and cultural heritage. However, these developments may mostly remain unrealized opportunities for those countries where, in absence of a long-standing tradition of HS remote sensing and companies producing HS sensors, there is no yet a consolidated and distributed community with HS satellite remote sensing technical and hands-on expertise (except for sparse individual scholars or groups already working with these technologies or with prior expertise on airborne data only). For example, this scenario can be found at the moment in Romania and, more widely, across Eastern Europe countries. While several academia and research organizations have strong competences in various strands of remote sensing – first of which multispectral optical and Synthetic Aperture Radar – as well as commercial companies exist and deliver applications and downstream services, HS satellite remote sensing has not yet reached the same level of maturity across the country. To stimulate an acceleration in this EO domain at national level, one of the most effective strategies is to identify a national champion (or a group of them) that can act as a technological innovator hub that may start creating a competence basis and promote further dissemination across the reference community through training initiatives. It is with this scope that the Romanian Space Agency (ROSA), as the national space body in charge of coordinating the national space research and application programs, promoting Romania's development in the space field, representing the Government in international cooperation programs and undertaking research oriented on space matters, promoted the application for and is coordinating the Horizon Europe "Reaching Excellence in Hyperspectral Remote Sensing" (EXPERT) project (https://www.expert-project.rosa.ro/). EXPERT is funded in the framework of HORIZON.4.1 “Widening participation and spreading excellence” program, “HORIZON-WIDERA-2023-ACCESS-02-01 - Twinning Bottom-Up” topic, “HORIZON Coordination and Support Actions” funding scheme. EXPERT aims to improvement of the excellence capacity and resources of ROSA in the area of HS remote sensing through knowledge and best practices transfer by ASI and DLR. Started in June 2024, EXPERT achieves such ambitious goal through international cooperation between the two space agencies – ASI & DLR – which are European leaders in HS sensor technologies, data analysis, applications and downstream services, and the national organization – ROSA – which has the institutional mandate and profile for playing the above said technological innovator hub and accelerator in Romania. Centered around the HS area of research and innovation, the EXPERT project targets an increased science and innovation capacity for the organization based in the widening country, consequently generating a greater involvement of local actors in the research and innovation process, both at national and European levels, through the specific actions designed for the wider communities around ROSA. Additionally, ROSA will develop a research profile and technical competence in order to fully exploit the R&D opportunities of such emerging field given the current rise of, and upcoming, HS satellite technologies and missions in Europe and beyond, under the guidance of ASI and DLR, which are at the forefront of HS remote sensing science and applications at global level. This paper illustrates the tiered approach and the various actions that are undertaken in EXPERT to achieve the above objectives: • Capacity building through training delivered by ASI and DLR to ROSA scientific and technical staff members, in order to build specialist competence and hands-on technical skills in collection, processing, post-processing and analysis of HS data collected from ground-based, airborne and spaceborne sensors; • Joint development of research use-cases focusing on the main applications that ROSA has identified as priorities to support the growth of the national satellite based downstream and applications sector, i.e. mining, agriculture and cultural heritage; • Outreach, networking and capacity building towards the user community, with the main focus on the Romanian academic, scientific and commercial sectors and, secondarily, neighboring countries in the Eastern Europe. Specific actions include: outreach webinars for awareness about HS remote sensing and basic and entry-level training; summer school devoted to EO researchers and professionals for an intensive specialist training; networking events to expand the community benefitting from the EXPERT impact and create opportunities for future partnerships and development in HS remote sensing at national level. Networking also encompasses liaising and partnering with other TWINNING project, such as AI4AGRI coordinated by the R&D Institute of Transilvania University of Brasov in Romania. It is worth noting that the capacity building, training and research use-cases rely on the joint exploitation of PRISMA and EnMAP. This choice accounts for the fact that PRISMA and EnMAP share several technical properties and are currently paving the way to the future generations of HS missions. In September 2022, ASI and DLR signed an implementation agreement to share HS data and the strategies, methods and results, and strengthen the synergies between the two missions (https://www.asi.it/en/2022/09/orbital-twinning-between-the-italian-prisma-satellite-and-the-german-enmapsatellite/). Therefore, in the context of this inter-agency twinning initiative, the EXPERT represents an excellent opportunity to capitalize on this cooperation and widen the benefits from PRISMA and EnMap HS data exploitation and applications development in the framework of the cooperation with ROSA. The present paper will showcase a model of cooperation between European space agencies, providing examples of good practices and knowledge transfer in EO. The EXPERT project has received funding from the European Union's HORIZON EUROPE "Widening participation and spreading excellence" programme under Grant Agreement No. 101160059.