Multi-Scale Remote Sensing of Tornado Effects

To achieve risk-based engineered structural designs that provide safety for life and property from tornadoes, sufficient knowledge of tornado wind speeds and wind flow characteristics is needed. Currently, sufficient understanding of the magnitude, frequency, and velocity structure of tornado winds remain elusive. Direct measurements of tornado winds are rare and nearly impossible to acquire, and the pursuit of in situ wind measurements can be precarious, dangerous, and even necessitating the development of safer and more reliable means to understand tornado actions. Remote-sensing technologies including satellite, aerial, lidar, and photogrammetric platforms, have demonstrated an ever-increasing efficiency for collecting, storing, organizing, and communicating tornado hazards information at a multitude of geospatial scales. Current remote-sensing technologies enable wind-engineering researchers to examine tornado effects on the built environment at various spatial scales ranging from the overall path to the neighborhood, building, and ultimately member and/or connection level. Each spatial resolution contains a unique set of challenges for efficiency, ease, and cost of data acquisition and dissemination, as well as contributions to the body of knowledge that help engineers and atmospheric scientists better understand tornado wind speeds. This paper examines the use of remote sensing technologies at four scales in recent tornado investigations, demonstrating the challenges of data collection and processing at each level as well as the utility of the information gleaned from each level in advancing the understanding of tornado effects

Multi-Scale Remote Sensing of Tornado Effects

To achieve risk-based engineered structural designs that provide safety for life and property from tornadoes, sufficient knowledge of tornado wind speeds and wind flow characteristics is needed. Currently, sufficient understanding of the magnitude, frequency, and velocity structure of tornado winds remain elusive. Direct measurements of tornado winds are rare and nearly impossible to acquire, and the pursuit of in situ wind measurements can be precarious, dangerous, and even necessitating the development of safer and more reliable means to understand tornado actions. Remote-sensing technologies including satellite, aerial, lidar, and photogrammetric platforms, have demonstrated an ever-increasing efficiency for collecting, storing, organizing, and communicating tornado hazards information at a multitude of geospatial scales. Current remote-sensing technologies enable wind-engineering researchers to examine tornado effects on the built environment at various spatial scales ranging from the overall path to the neighborhood, building, and ultimately member and/or connection level. Each spatial resolution contains a unique set of challenges for efficiency, ease, and cost of data acquisition and dissemination, as well as contributions to the body of knowledge that help engineers and atmospheric scientists better understand tornado wind speeds. This paper examines the use of remote sensing technologies at four scales in recent tornado investigations, demonstrating the challenges of data collection and processing at each level as well as the utility of the information gleaned from each level in advancing the understanding of tornado effects

Investigation of rapid remote sensing techniques for forensic wind analyses

Perishable damage data resulting from severe windstorms require efficient and rapid field collection techniques. Such datasets permit forensic damage investigations and characterization of civil infrastructure. Ultimately, observed structural damage serves as a proxy approach to estimate wind speeds for storms that include hurricanes, tornadoes, straight-line winds, etc. One of the more common methods to collect, preserve, and reconstruct three-dimensional damage scenes is the use of an unmanned aerial system (UAS), commonly known as a drone. Onboard photographic payloads permit scene reconstruction via structure-from-motion; however, such approaches often require direct site access and survey points for accurate results, which limit its efficiency. In this presentation, the use of UAS platforms with and without surveyed ground control points is investigated to understand the accuracy if site access is not possible. UAS datasets will be compared to lidar data of various structures collected following the 2017 Hurricane Harvey near Rockport, TX

NDM-506: CURRENT METHODS AND FUTURE ADVANCES FOR RAPID, REMOTE-SENSING-BASED WIND DAMAGE ASSESSMENT

Remote-sensing information provides an effective basis for the rapid assessment of wind damage. The development of remote-sensing based assessments has received notable attention over the past decade, although automated algorithms have not yet achieved the speed, objectivity, and reliability desired for practical implementation in time-critical damage assessments. The current standard practice for making swift, objective, and widespread assessments of wind damage currently consists of rapid visual interpretation of first-available imagery. Techniques for rapidly accomplishing widespread damage assessments by visual inspection have been implemented in recent major tornado outbreaks in Birmingham-Tuscaloosa, Alabama and Joplin, Missouri (2011). Quickly emerging technologies, such as unmanned aerial vehicles (UAVs) and laser scanners, are helping to improve both the speed and the accuracy of damage assessments, in particular for rapid and target-specific data collection at very high spatial resolutions. Applications of these emerging technologies following recent severe tornadoes at Pilger, Nebraska (2014) and Pampa, Texas (2015) have demonstrated their role in helping to refine strategies for making rapid semi-automated damage assessments. Algorithms for comparing before-and-after remote sensing imagery are also of great interest for the future development of automated damage detection. Current development activities are centered on high-resolution before-and-after aerial images of recent tornado damage

NDM-504: MULTI-PLATFORM TORNADO DAMAGE SCENE PRESERVATION

A severe tornado system produced damage to engineered metal buildings at an industrial facility outside Pampa, TX and toppled several nearby center-pivot irrigation structures. Rapid remote-sensing preservation of this overall damage scene was of particular necessity: access to the industrial facility was prohibited, and the overall size of the center-pivot irrigation system disallowed rapid direct measurement of member displacements. Engineers and architects from West Texas A&M University, University of Nebraska-Lincoln, and Texas Tech University collaborated to acquire and preserve the damage scene for future study, using a suite of existing and emerging platforms: including 3D point clouds derived from aerial FoDAR, aerial drone imaging, terrestrial laser scanning, and terrestrial digital photogrammetry as well as two-dimensional, four-band satellite imaging. Data collection using these various platforms offers guidance for the future remote-sensing preservation of damage scenes, the validation of estimated wind speeds currently employed in the Enhanced Fujita Scale of tornado intensity, and the further development of techniques for automated remote-sensing-based wind damage assessments

NDM-505: DEVELOPMENT OF THE ASCE/SEI STANDARD FOR THE ESTIMATION OF TORNADO WIND SPEEDS

Development of the new ASCE/SEI consensus standard for wind speed estimation in tornadoes began in 2014 and is currently underway. The intent of the new standard is to standardize the methods used to estimate the wind speeds in tornadoes including improvements and expansions for the damaged-based Enhanced Fujita Scale (EF Scale), with potential to extend the scope of the standard to include other windstorms. The standard will include sections on the EF Scale, radar measurements, tree fall pattern analysis, data archives, forensic engineering analysis, in-situ measurements (anemometry), and remote-sensing applications. Users of the standard will include wind, structural and forensic engineers, meteorologists, climatologists, forest biologists, risk analysts, hazards modellers, emergency managers, building and infrastructure designers, the insurance industry, and the media. The standard is intended for adoption by the National Weather Service and for use by storm study teams and researchers as a guide for conducting storm surveys and analysis of storm data. Development of the standard highlights the current state-of-the art in wind speed estimation and also identifies areas where new research is needed. Development of the standard will include a public ballot period. The standard is scheduled to be completed in 2019

Multi-Scale Remote Sensing of Tornado Effects

To achieve risk-based engineered structural designs that provide safety for life and property from tornadoes, sufficient knowledge of tornado wind speeds and wind flow characteristics is needed. Currently, sufficient understanding of the magnitude, frequency, and velocity structure of tornado winds remain elusive. Direct measurements of tornado winds are rare and nearly impossible to acquire, and the pursuit of in situ wind measurements can be precarious, dangerous, and even necessitating the development of safer and more reliable means to understand tornado actions. Remote-sensing technologies including satellite, aerial, lidar, and photogrammetric platforms, have demonstrated an ever-increasing efficiency for collecting, storing, organizing, and communicating tornado hazards information at a multitude of geospatial scales. Current remote-sensing technologies enable wind-engineering researchers to examine tornado effects on the built environment at various spatial scales ranging from the overall path to the neighborhood, building, and ultimately member and/or connection level. Each spatial resolution contains a unique set of challenges for efficiency, ease, and cost of data acquisition and dissemination, as well as contributions to the body of knowledge that help engineers and atmospheric scientists better understand tornado wind speeds. This paper examines the use of remote sensing technologies at four scales in recent tornado investigations, demonstrating the challenges of data collection and processing at each level as well as the utility of the information gleaned from each level in advancing the understanding of tornado effects

Multi-Scale Remote Sensing of Tornado Effects

To achieve risk-based engineered structural designs that provide safety for life and property from tornadoes, sufficient knowledge of tornado wind speeds and wind flow characteristics is needed. Currently, sufficient understanding of the magnitude, frequency, and velocity structure of tornado winds remain elusive. Direct measurements of tornado winds are rare and nearly impossible to acquire, and the pursuit of in situ wind measurements can be precarious, dangerous, and even necessitating the development of safer and more reliable means to understand tornado actions. Remote-sensing technologies including satellite, aerial, lidar, and photogrammetric platforms, have demonstrated an ever-increasing efficiency for collecting, storing, organizing, and communicating tornado hazards information at a multitude of geospatial scales. Current remote-sensing technologies enable wind-engineering researchers to examine tornado effects on the built environment at various spatial scales ranging from the overall path to the neighborhood, building, and ultimately member and/or connection level. Each spatial resolution contains a unique set of challenges for efficiency, ease, and cost of data acquisition and dissemination, as well as contributions to the body of knowledge that help engineers and atmospheric scientists better understand tornado wind speeds. This paper examines the use of remote sensing technologies at four scales in recent tornado investigations, demonstrating the challenges of data collection and processing at each level as well as the utility of the information gleaned from each level in advancing the understanding of tornado effects