Damage assessments provide insight into the occurrence, intensity, and distribution of tornadoes and other severe weather phenomenon. Current ground survey and satellite assessments, however, are restricted by available resources (e.g., personnel, time, and cost), accessibility, technological limitations, and damage indicators used to infer storm intensity. Compared to ground-level photos, UAS imagery reveals a broader extent of damage, including areas that are difficult to access on foot. Its broader overhead view also better captures spatial variations in damage that reflect gradients in tornado and storm wind intensity—details that are difficult to capture with ground-based point indicators.
Scientists at NSSL and CIWRO utilize uncrewed aerial systems (UASs) to document storm damage. These platforms collect high-resolution video, imagery, and elevation data- including multi-spectral imagery at resolutions as fine as 2.5 cm – allowing us to observe how storms affect and are influenced by the land surface. These high-resolution datasets can be used to validate radar observations and numerical simulations, ultimately improving our understanding of surface interactions with storms. This can be done by characterizing debris deposition, mapping damage indicators relative to storm attributes, and comparing aerial imagery to ground surveys.
The image above illustrates the imaging capabilities for detecting tornado damage through an agricultural field. On the left is 2.5 cm resolution visible imagery; on the right is the Normalized Difference Vegetation Index (NDVI), derived from multispectral data collected by the UAS. NDVI is commonly used to measure vegetation health and density. Healthy vegetation appears green, while tornado-damaged areas are highlighted in yellow, clearly revealing the storm’s path through the field.
Equipment
Skydio 2
The Skydio 2 is used to identify storm damage, collect imagery that can be shared with local emergency managers and other agencies, and determine targeted areas of interest for large-scale mapping. The Skydio 2 is equipped with a Sony IMX577 20.1 MP visible camera, yielding imagery with spatial resolution of 3 cm or less at a flying height of 400 ft above ground level.
The Skydio 2 has a battery life of up to 23 minutes, flight range of 3.5 kilometers, and a maximum wind speed resistance of 25 mph. The Skydio 2 can operate in temperatures ranging from -5C to 40C, allowing for a wide range of applications. The Skydio 2 system includes obstacle avoidance and object identification and tracking.
Trinity F90+
The Quantum Sytems Trinity F90+ is used to map storm damage and obtain land surface information for modeling and in-situ observation studies. The Trinity F90+ has vertical take-off and landing capabilities and can map up to 700 hectares at 120 m AGL on a single battery. It is equipped with multiple payloads.
The first is the dual Sony UMC R10C 20.1 MP camera and Micasense Red-Edge MX camera, to collect visible and multispectral imagery, respectively. In storm damage assessments, multispectral imagery can detect vegetation damage that otherwise would be indiscernible to the human eye based on the spectral response of vegetation in the red, red-edge, and near-infrared bands. The second, and newer payload, is the Micasense Altum-PT camera which can capture thermal and multispectral imagery with up to 2.5 cm spatial resolution. The final payload is the Quantum Systems QUBE 240 LiDAR unit which can be used to collect high resolution elevation information.
The first is the dual Sony UMC R10C 20.1 MP camera and Micasense Red-Edge MX camera, to collect visible and multispectral imagery, respectively. In storm damage assessments, multispectral imagery can detect vegetation damage that otherwise would be indiscernible to the human eye based on the spectral response of vegetation in the red, red-edge, and near-infrared bands. The second, and newer payload, is the Micasense Altum-PT camera which can capture thermal and multispectral imagery with up to 2.5 cm spatial resolution. The final payload is the Quantum Systems QUBE 240 LiDAR unit which can be used to collect high resolution elevation information.
Autel EVO II Pro V3
The Autel EVO II Pro V3 is used to capture high-resolution video and detailed imagery of storm damage in remote or otherwise inaccessible areas. This technology enables our team to accurately assess the path, severity, and extent of damage caused by severe weather events, even when traditional ground access is impossible. The EVO II Pro V3 helps us strategically plan and optimize subsequent mapping missions conducted with the Trinity F90+. This ensures maximum coverage and precision during data collection efforts.
Equipped with a premium Sony 1″ CMOS sensor, the drone delivers 6K video footage and 20-megapixel still images, providing clarity and detail for analysis.