Periodic Reporting for period 1 - UAWOS (Unmanned Airborne Water Observing System)
Periodo di rendicontazione: 2023-02-01 al 2024-07-31
High-resolution hydrometric monitoring of rivers is important because the climate crisis severely affects frequency and magnitude of extreme events and flood/drought risks are evolving fast. However, hydrometric monitoring data is scarce and lacks spatial resolution and coverage, particularly in remote and hard-to-reach rivers in alpine, Arctic and tropical regions. Advanced in-situ monitoring technologies have to be combined with satellite earth observation (EO) to obtain accurate, reliable, long-time and spatio-temporally resolved information for effective decision support, risk assessment, investment analysis in the context of climate change adaptation, and operational forecasting, surveillance, and management of rivers.
Traditional in-situ hydrometric monitoring of rivers is station-based. Water surface elevation (WSE), flow velocity, bed geometry and river discharge are measured using sensors that are installed in-situ, either in direct contact or in close proximity to the flow. In-situ station-based monitoring infrastructure is vulnerable and often fails during extreme flooding events, when the value of information is very high. Station-based monitoring networks lack spatial resolution and have been declining in many regions, particularly in remote and hard-to-reach areas. Data accessibility is increasingly restricted because of growing conflicts between countries over water resources allocation.
UAWOS develops a drone-borne water observing system providing key hydrometric variables (bathymetry, flow velocity, discharge, water surface elevation) at high spatial resolution and coverage (Figure 1). Because the system works airborne and contactless, it is ideally suited for remote and hard-to-reach areas and extreme physical conditions. UAWOS integrates airborne data streams with water and land elevation datasets available from different satellite EO missions, including Sentinel-3, ICESat-2 and SWOT.
Traditional in-situ hydrometric monitoring of rivers is station-based. Water surface elevation (WSE), flow velocity, bed geometry and river discharge are measured using sensors that are installed in-situ, either in direct contact or in close proximity to the flow. In-situ station-based monitoring infrastructure is vulnerable and often fails during extreme flooding events, when the value of information is very high. Station-based monitoring networks lack spatial resolution and have been declining in many regions, particularly in remote and hard-to-reach areas. Data accessibility is increasingly restricted because of growing conflicts between countries over water resources allocation.
UAWOS develops a drone-borne water observing system providing key hydrometric variables (bathymetry, flow velocity, discharge, water surface elevation) at high spatial resolution and coverage (Figure 1). Because the system works airborne and contactless, it is ideally suited for remote and hard-to-reach areas and extreme physical conditions. UAWOS integrates airborne data streams with water and land elevation datasets available from different satellite EO missions, including Sentinel-3, ICESat-2 and SWOT.
In the reporting period, the project's main achievements are as follows:
- UAWOS developed the following drone hydrometry payloads: (1) a radar altimeter for water surface elevation monitoring, (2) sonar and water penetrating radar (WPR) payloads for river bathymetry monitoring (Figure 2), (3) a Doppler radar velocimetry payload for monitoring surface flow velocity. All payloads are integrated with the SPH Engineering SkyHub onboard data logger and are commercially available from SPH Engineering.
- UAWOS developed a surveying protocol for river water surface elevation, using the new radar altimetry payload. Using this surveying protocol, river water surface elevation can be mapped efficiently along river reaches of dozens of kilometers in length. Surveying protocols for riverbed geometry, river velocimetry and river discharge are currently under development.
-UAWOS applied the new payloads and surveying protocols in three UAS hydrometry surveys in the Rönne å river (Southern Sweden), the Isar River (South Germany) and the Orco/Po rivers (Northern Italy). Datasets obtained in these surveys were validated with ground truth measurements and are publicly available at https://data.dtu.dk/projects/UAWOS/164815(si apre in una nuova finestra). Some of the datasets have already been exploited for scientific publications (https://uawos.dtu.dk/publications(si apre in una nuova finestra)).
-UAWOS developed concepts and tools to combine WSE records from satellite altimetry with UAS hydrometry datasets and hydraulic models to estimate river discharge from WSE at high accuracy. River WSE is routinely available at virtual stations from nadir radar and laser altimetry and all along the river chainage from SWOT.
- UAWOS developed the following drone hydrometry payloads: (1) a radar altimeter for water surface elevation monitoring, (2) sonar and water penetrating radar (WPR) payloads for river bathymetry monitoring (Figure 2), (3) a Doppler radar velocimetry payload for monitoring surface flow velocity. All payloads are integrated with the SPH Engineering SkyHub onboard data logger and are commercially available from SPH Engineering.
- UAWOS developed a surveying protocol for river water surface elevation, using the new radar altimetry payload. Using this surveying protocol, river water surface elevation can be mapped efficiently along river reaches of dozens of kilometers in length. Surveying protocols for riverbed geometry, river velocimetry and river discharge are currently under development.
-UAWOS applied the new payloads and surveying protocols in three UAS hydrometry surveys in the Rönne å river (Southern Sweden), the Isar River (South Germany) and the Orco/Po rivers (Northern Italy). Datasets obtained in these surveys were validated with ground truth measurements and are publicly available at https://data.dtu.dk/projects/UAWOS/164815(si apre in una nuova finestra). Some of the datasets have already been exploited for scientific publications (https://uawos.dtu.dk/publications(si apre in una nuova finestra)).
-UAWOS developed concepts and tools to combine WSE records from satellite altimetry with UAS hydrometry datasets and hydraulic models to estimate river discharge from WSE at high accuracy. River WSE is routinely available at virtual stations from nadir radar and laser altimetry and all along the river chainage from SWOT.
In the reporting period, the project's main results beyond the state of the art are as follows:
- UAWOS developed the first operational drone-borne Doppler radar velocimetry solution and thoroughly validated its performance against in-situ monitoring technology and drone-borne image velocimetry. This result is documented in the following pre-print: https://doi.org/10.22541/au.170967865.54122848/v1(si apre in una nuova finestra). Potential impact: This result will enable efficient airborne monitoring of surface flow velocity in large rivers, because Doppler radar surveying is straightforward, independent of daylight conditions, independent of trackable features in the flow and data volumes are much lower than for comparable image velocimetry techniques.
- UAWOS developed and commercialized a complete set of UAS hydrometry payloads for river surveying. While drone-borne river bathymetry and water surface elevation surveying has been demonstrated prior to the project, no established commercial solutions have been available and UAS hydrometry surveys typically used in-house solutions developed in university labs. Potential impact: This result will enable uptake of UAS hydrometry as an alternative/complement to traditional in-situ river surveying. The entry threshold for this type of surveys has been lowered significantly with the availability of commercial, off-the-shelf solutions for water surface elevation, riverbed geometry and velocimetry surveying. Performance of the new UAS hydrometry payloads has been validated against traditional technology and survey data are publicly shared on https://data.dtu.dk/projects/UAWOS/164815(si apre in una nuova finestra)
- UAWOS developed the first operational drone-borne Doppler radar velocimetry solution and thoroughly validated its performance against in-situ monitoring technology and drone-borne image velocimetry. This result is documented in the following pre-print: https://doi.org/10.22541/au.170967865.54122848/v1(si apre in una nuova finestra). Potential impact: This result will enable efficient airborne monitoring of surface flow velocity in large rivers, because Doppler radar surveying is straightforward, independent of daylight conditions, independent of trackable features in the flow and data volumes are much lower than for comparable image velocimetry techniques.
- UAWOS developed and commercialized a complete set of UAS hydrometry payloads for river surveying. While drone-borne river bathymetry and water surface elevation surveying has been demonstrated prior to the project, no established commercial solutions have been available and UAS hydrometry surveys typically used in-house solutions developed in university labs. Potential impact: This result will enable uptake of UAS hydrometry as an alternative/complement to traditional in-situ river surveying. The entry threshold for this type of surveys has been lowered significantly with the availability of commercial, off-the-shelf solutions for water surface elevation, riverbed geometry and velocimetry surveying. Performance of the new UAS hydrometry payloads has been validated against traditional technology and survey data are publicly shared on https://data.dtu.dk/projects/UAWOS/164815(si apre in una nuova finestra)