Advancement of Infrasound Propagation Calculation Techniques Using Mesoscale Atmospheric and Terrain Specifications
Abstract
Numerical calculation of infrasound propagation paths is necessary to support accurate infrasound event identification, phase association, and source location. Predicting the details of infrasound propagation relies both on propagation models that capture the fundamental physical processes and on characterization of the propagation medium, namely the global atmosphere from the ground to altitudes above 100 km. Therefore the accuracy of propagation modeling depends in part on the fidelity of the atmospheric characterization. Furthermore, for infrasound propagation at regional and local ranges, characterized by higher frequencies than propagation at global ranges, effects of the boundary conditions of the propagation domain, in particular the terrain elevation, become increasingly important. The analysis tool kit Infrasound Modeling of Atmospheric Propagation (InfraMAP) integrates infrasound propagation models and environmental representations, including synoptic updates of the atmospheric specification at low and middle altitude, such as the output from numerical weather prediction models that supplement climatological characterization of temperature, wind, and air composition at high altitude. The Naval Research Laboratory (NRL) Ground-to-Space (G2S) semi-empirical spectral model provides a global specification of the atmosphere that can be utilized in InfraMAP. These capabilities for propagation calculation and atmospheric specification allow infrasound researchers to investigate critical propagation phenomena, conduct sensitivity studies, and compare results of numerical modeling with observed signals. Recent efforts develop techniques for utilizing accurate, high-resolution regional atmospheric specifications and terrain elevation databases with infrasound propagation modeling codes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2007
- Accession Number
- ADA519266
Entities
People
- David E. Norris
- Douglas P. Drob
- Robert G. Gibson
Organizations
- United States Naval Research Laboratory