Item: Infrasound Detection of Avalanches: operational experience from 28 combined winter seasons and future developments
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Title: Infrasound Detection of Avalanches: operational experience from 28 combined winter seasons and future developments
Proceedings: International Snow Science Workshop Proceedings 2018, Innsbruck, Austria
Authors:
- Walter Steinkogler [ Wyssen Avalanche Control, Reichenbach, Switzerland ]
- Giacomo Ulivieri [ GeCo s.r.l, Florence, Italy ]
- Sandro Vezzosi [ GeCo s.r.l, Florence, Italy ]
- Jordy Hendrikx [ Snow and Avalanche Laboratory, Montana State University, Bozeman, MT, USA ]
- Alec Van Herwijnen [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Tore Humstad [ Norwegian Public Roads Administration, Molde, Norway ]
Date: 2018-10-07
Abstract: We present an overview of multiple verification campaigns performed to evaluate the performance of and experience with IDA® (Infrasound Detection of Avalanches) operational systems in Austria, Switzerland, Canada, Norway and the USA. This work focuses on operationally relevant facts and recommendations for the design of infrasound systems. The comprehensive dataset consists of 28 combined operational winter seasons at 10 different locations, covering a wide range of avalanche sizes and types, snow climates (stratigraphy and snow depth), topographies and site-specific characteristics. The IDA® systems automatically detected natural avalanches, artillery gun shots and detonations as well as explosions from different remote avalanche control systems. Results show that the operational reliability of IDA® is limited to avalanches of size class > 2.5 (corresponding to ~ 500 m of run-out distance and 5 ha), both dry and wet, within a distance of 3-4 km from the array, with a probability of detection (POD) between 40 and 90% and a false alert ratio (FAR) between 0 and 20%. The POD increases with size and decreases with distance. Differences in performance are mainly related to site-specific characteristics. Site-specific calibration of the automatic algorithm as well as tuning of the thresholds is a key factor for the performance optimization. The presence of local terrain features and complex topography can limit the monitoring of certain avalanche paths. Preliminary results suggest the use of multiple arrays and adapted algorithms can be an effective solution to mitigate this limitation. Wind noise, ice layers or a dense snowpack can significantly reduce the detection capability and in extreme cases render the system inoperative. However, a detailed design study, optimized site selection, properly installation solutions, hardware robustness improvements and a clear definition of the operational requirements of the local avalanche control team can help minimizee these limitations.
Object ID: ISSW2018_O07.8.pdf
Language of Article: English
Presenter(s):
Keywords: Infrasound detection, avalanche, operational
Page Number(s): 621-626
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