How Gunshot Detection Works
Gun is fired
When a gun is fired, the sound of a muzzle blast radiates outward.
Gunshot is Detected and Located
Acoustic sensors are triggered by the impulsive sound. THe sound is classified as a gunshot using artificial intelligence and triangulation determines the precise location.
Gunshot is Reviewed
The data is relayed to the Shotspotter Incident Review Center where analysts quickly audit the data and publish confirmed gunsots to police.
Alerts are sent to dispatch centers and patrol officers’ smartphones and MDTs for immediate response. The entire process takes less than 60 seconds.
A Closer Look
Accurately detecting and precisely locating gunshots is a challenging problem given the many obstacles of buildings, trees, echoes, wind, rain and street noise. ShotSpotter has met the challenge with our innovative technology, developed over 20 years and protected by more than 30 patents for intellectual property. Our patents can be found here.
DETECTION & LOCATION
First, highly-specialized software analyzes audio signals for potential gunshots.
- The software filters out ambient background noise, such as traffic or wind, and listens for impulsive sounds characteristic of gunfire; we call these pulses.
- If the sensor detects a pulse, it extracts pulse features from the waveform, such as sharpness, strength, duration and decay time.
- If at least three sensors detect a pulse that is believed to be a gunshot, the sensor then sends a small data packet to cloud servers where multilateration is used based on time difference of arrival and angle of arrival of the sound to determine a precise location.
After the software determines the location of the sound source, it analyzes the pulse features to determine if the sound is likely to be gunfire.
- To evaluate and classify the sound, algorithms consider the distance from the sound source, pattern matching and other heuristic methods.
- The machine classifier uses an algorithm to compare the sound to a large database of known gunfire and other impulsive sounds. It acts as a noise filter to remove sounds that are clearly not gunfire such as fireworks, helicopters and construction equipment.
- The remaining incidents are sent to acoustic experts in our Incident Review Centers (IRC) for additional analysis and it is published to police or dismissed.
The system pushes the alert notification to law enforcement and emergency responders.
- Incident notifications are triggered when the incident is confirmed as gunfire.
- Gunfire alerts are pushed to ShotSpotter mobile apps, and desktop and browser apps.
- The entire transaction from initial gunfire to alert takes place in less than 60 seconds.
1. Capture Everything in One Place Easily create digital case folders and document investigative activities, scene details, observations, videos, images, notes and other attachments into one central source of truth.
Capture Everything in One Place
2. Organize Instantly Automatically generate a searchable, chronological case index as information is collected and investigative activities are completed.
Case Chronology List
3. Solve Cases Faster Guide different types of investigations with pre-configured, customizable checklists of action items so nothing slips through the cracks, and generate immediate insights through link analysis to uncover patterns.
How Patrol Management Works