Item: Avalanche rescue: frequencyvariation as a search methodology
Title: Avalanche rescue: frequencyvariation as a search methodology
Proceedings: 1990 International Snow Science Workshop, Bigfork, Montana USA, October 9-13
Authors: Derek A Calomeni, James C. Rogers
Abstract: A comparison was made of the human ear's sensitivity to detecting variations in frequency versus variations in amplitude. The purpose was to investigate a potential improvement in the effectiveness of avalanche victim search and rescue operations. Twenty subjects performed simulated searches using a computer mouse located on a grid, which enabled the tracking of search paths. Subjects performed course searches and used bracketing to pinpoint victims. Various electronic instruments were used to simulate both frequency and amplitude variations. The subjects performed 18 individual searches. Path lengths were analyzed by recording mouse movement over the search grid. Individual search times were normalized and an overall comparison of detection, convergence, and the total search times for both frequency and amplitude variations were made. The effective sizes of the search or detection circles of both methods were determined in order to analyze their effect on search times. For each site a comparison was made of the effectiveness of each method by plotting frequency detection time versus amplitude detection time. It is suggested that the frequency variation method can provide shorter victim detection time.
Keywords: search methodology, avalanche, rescue, victims, detection
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