Book excerpt: Inter-Mountain Laboratories Inc. of Sheridan, WY has developed an infrasonic avalanche monitoring system that is being used by the Wyoming Department of Transportation on two avalanche slide paths on Teton Pass near Jackson, WY. This study focuses upon the signal processing behind this type of system, and investigates several different signal processing techniques that might be used to improve the reliability and capabilities of such a system. The methods explored are the extraction of reliable features for avalanche detection, and cross-correlation updating techniques that could be used to improve reliability of the system as well as decrease the computational burden of an avalanche detection system.