Professor for Remote Sensing
Vienna University of Technology
Monitoring Soil Moisture and Flooding in Arid Environments with Radar Satellite Constellations
In arid regions, water is the primary limiting factor for all forms of life. The scarcity of water influences every aspect of life, from ecosystem health to agricultural production and human wellbeing. Even so, storms can occasionally bring intense rainfall that can lead to significant flooding in areas that have little capacity to handle large volumes of water. This sudden influx of water can cause rivers to overflow, erode the land surface, and overwhelm drainage systems. For these reasons, it is as important to monitor hydrological processes in arid environment as in more humid environments. In this contribution I will examine the capabilities of three European services to monitor soil moisture and flood extent in arid environments: The H SAF service of EUMETSAT uses C-band backscatter data acquired by the Advanced Scatterometer (ASCAT), which has been flown on board of a series of three Metop satellites, to provide coarse-resolution (15-25km) soil moisture data with sub-daily revisit times. The Copernicus Land Monitoring and Emergency Management services use C-band backscatter measurements acquired by the Sentinel-1 Synthetic Aperture Radar mission to provide flood maps at 20 m and soil moisture at 1km respectively. Although the ASCAT and Sentinel-1 backscatter measurements differ in terms of spatial and temporal resolution, they both measure the same physical property: the backscatter coefficient at two nearby C-band frequencies (5.255 GHz for ASCAT and 5.405 GHz for Sentinel-1). This frequency range is especially sensitive to water, whether within the soil or on its surface. Given that vegetation cover is typically low in arid environments, it might hence be expected that retrieving soil moisture and flood extent in these regions is relatively straightforward. Unfortunately, the opposite is true. The challenges are manifold. First, among all ice-free land surface areas, backscatter shows the greatest variation in arid environments. It can be very high over rough rock or stony surfaces, and extremely low over deep sand. Second, under dry conditions, C-band waves penetrate deep into the soil, making the measurements sensitive to subsurface scatterers. This results in a situation where (i) backscatter from deep sand is as low as for flood water, and (ii) backscatter does not have a unique relationship to soil moisture. Consequently, flood mapping and soil moisture retrieval are highly uncertain in many arid regions. After discussing how the three European services deal with this situation, I will explore potential approaches to enhance the radar-based soil moisture and flood data through the development of new algorithms, the incorporation of additional data, or a combination of both. Additionally, I will highlight how the pronounced backscatter signals in arid environments could offer valuable insights for creating new soil maps.
Professor and former Head of the Department of Geomatics Engineering
University of Calgary
From Mobile Mapping to Autonomous Systems: State of the Art and Future Trends
The evolution of integrated navigation systems has been transformative, progressing from their foundational role in mobile mapping to their critical function in autonomous systems. This keynote will explore the state-of-the-art technologies driving this transition and examine future trends shaping the field. Mobile mapping relies on navigation systems, cameras, LiDAR, and other sensors to accurately geo-reference and map street-level environments. These same sensors, when used in autonomous systems, shift from passive data collection to active real-time perception and decision-making, enabling safe and precise navigation. This presentation will highlight how advancements in sensor fusion, GNSS-aided and GNSS-denied navigation, and AI-driven processing are enhancing system accuracy, continuity, and resilience. The discussion will cover the design approaches, capabilities, and limitations of integrated navigation systems, emphasizing their ability to operate seamlessly in complex environments—regardless of weather, lighting, or infrastructure constraints. Real-world implementations will illustrate current performance levels and future possibilities, demonstrating how navigation solutions are evolving to meet the growing demands of automation. As industries increasingly adopt autonomous technologies in transportation, logistics, robotics, and smart cities, the need for robust and intelligent navigation is more critical than ever. This keynote will provide insights into the technological breakthroughs shaping the next decade, paving the way for a future where autonomous systems navigate safely and efficiently in any environment.