GPS-Denied Personnel Tracking: EEPTS

Know where your people are when GPS, RF, and infrastructure are gone.

The Extended Embedded Pedestrian Tracking System (EEPTS) reconstructs a person’s full motion path in real time from a single body-worn inertial sensor. It needs no GPS, radio beacons, cameras, or installed infrastructure. All processing runs onboard the 3-Space sensor, so position data is available as it is computed, with no post-processing and no external host.

Developed through a defense-funded program and validated in field trials across forest, urban, and mixed terrain.

≤3% error over distance traveled
≤3 m CEP per 100 m
1 sensor, worn on the chest, shoulder, waist, or back
0 external infrastructure required

Built for the Places GPS Fails

GPS breaks down inside buildings, underground, between tall structures, under dense tree cover, and anywhere the signal is denied or degraded. EEPTS was developed through a defense-funded program to maintain personnel accountability in exactly those conditions.

• Indoor buildings and warehouse spaces
• Subterranean areas
• Urban canyons
• Dense forest and rough, undeveloped trails
• Mixed terrain with transitions between all of the above

Proven in Field Trials

Every result below came from dead reckoning alone. GPS was not used at any point.

Dense Forest, Rough Terrain

An 879.4 meter trail with significant elevation gain, steep rises, and switchbacks.

Urban Terrain

A 3,740 meter route through urban canyons, where building reflections typically degrade GPS accuracy. Every trial ended well inside the error ring.

Mixed Terrain, Mixed Movement

A 1,702.7 meter route across developed and undeveloped ground while walking, running, and crawling, with transitions between modes. These trials are the most representative of real-world performance across the full range of use.

How It Works

EEPTS runs entirely inside the sensor, using inertial data and embedded motion-tracking algorithms.

• Wear it anywhere: position, orientation, and user independent, with no fixed mounting or per-person calibration
• Recognizes how people move: classifies walking, jogging, running, and crawling
• Seamless GPS handoff: transitions to and from GPS-available areas automatically
• Accurate heading: built-in World Magnetic Model (WMM) corrects for magnetic declination
• Flexible output: real-time position as latitude/longitude or as offsets in meters
• Full sensor function: complete AHRS/IMU output runs at the same time

Applications

• Military and defense: warfighter navigation and tracking in GPS-denied environments
• Firefighters and first responders: personnel accountability inside structures and underground
• Industrial safety: employee monitoring for safety and operational efficiency
• Compliance: personnel traceability records
• Asset tracking: hand-carried tools and devices

Integration Options

• Drop-in: available within the 3-Space Sensor v3 family
• License: available as a linkable/loadable binary module for qualified users
• Developer tools: Python and C APIs, open protocol with real-time access to all data and settings, 3-Space Sensor Suite, EEPTS evaluation mapping application, and a development kit

Test EEPTS in Your Environment

Tell us about your platform and operating conditions. Our engineers will help you evaluate EEPTS, scope a license, or integrate it into your system.