Multipath
Definition
The phenomenon in which a sound from a single source reaches a microphone via multiple paths (direct plus multiple reflections), each arriving at a slightly different time; a major complication in urban gunshot acoustic reconstruction.
- Cause
- Sound reaching a microphone via multiple reflected routes
- Effect
- Multiple arrivals at slightly different times
- Complicates
- Urban gunshot acoustic reconstruction
- Field
- Forensic acoustics
Common questions
Why does multipath make gunshot origin reconstruction harder in cities?+
Reflections off buildings and other hard surfaces can arrive at a microphone almost as strongly as the direct sound, so an analyst measuring time-of-arrival for triangulation risks mistaking a reflected path for the direct one and mislocating the shot.
How do analysts try to separate the direct sound from its reflections?+
They typically use the earliest, sharpest amplitude peak in the recorded waveform as the direct arrival, since reflected paths are longer and therefore arrive later, though dense urban geometry can still make the direct peak hard to isolate.
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