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A GNSS Multipath Model for Aerial Navigation

The availability and integrity of navigation systems utilizing Global Navigation Satellite System (GNSS) signals is adversely affected by signal multipath, a phenomena strongly dependent on the local environment of the GNSS receiver antenna. This paper presents a ray-tracing method to model multipath, specifically considering specular reflections and their impact on the received signal. The model is applied to study the effect of satellite elevation and azimuth on signal attenuation in a simulation-based case-study. The case study demonstrates that the multipath contribution to signal...

Effects of Host-rock Fracturing on Elastic-deformation Source Models of Volcano Deflation

Volcanoes commonly inflate or deflate during episodes of unrest or eruption. Continuum mechanics models that assume linear elastic deformation of the Earth's crust are routinely used to invert the observed ground motions. The source(s) of deformation in such models are generally interpreted in terms of magma bodies or pathways, and thus form a basis for hazard assessment and mitigation. Using discontinuum mechanics models, we show how host-rock fracturing (i.e. non-elastic deformation) during drainage of a magma body can progressively change the shape and depth of an elastic-deformation...