Narrowband  |   Broadband  |  2025-07-23

NextNav Delivers Pinpoint Z-Axis Accuracy in July 4th Public Safety Test at Washington Monument

Source: Rob Clark - NextNav
Curated by: Gert Jan Wolf - Editor-in Chief for The Critical Communications Review

Last July 4th, amidst a celebration with well over 200,000 people taxing local cellular networks, NextNav, in partnership with forward-thinking public safety agencies, undertook one of its most ambitious tests to date. The mission: to prove the accuracy, reliability, and resilience of our Pinnacle Z-axis service and 3D visualization tools in one of the most challenging environments imaginable.

This second phase of testing, led by the Arlington County Fire Department and the Arlington County Department of Emergency Communications 9-1-1 Center, and hosted by the DC Homeland Security and Emergency Management Agency, was specifically designed to assess performance under the most strenuous, real-world conditions.

The Challenge: A Real-World Gauntlet
Success required overcoming three immense obstacles simultaneously:

  1. Structural Interference: The Washington Monument’s dense building materials are known to block or degrade conventional location signals. During the test, this proved true for legacy GPS, whose X/Y coordinates became wildly inconsistent.
  2. Network Congestion: The massive July 4th crowd placed cellular networks under extreme load, creating the perfect environment to validate the resiliency of NextNav’s services during a mass gathering event.
  3. Complex Scenarios: The tests simulated life-or-death public safety incidents, requiring accurate tracking of multiple “9-1-1 callers” and “first responders” as they moved through the structure.

The Test: From the Metro to the Monument
After initial validation in Arlington and successfully tracking personnel through subterranean Metro stations, the team arrived at the National Mall for the final and most demanding tests at the Washington Monument. Using standard smartphones equipped with the NextNav Pinnacle View and 3AM FLORIAN applications, the team ran two critical scenarios.

  • Scenario 1: The 100-Foot Ascent
    In the first test, a team simulating “9-1-1 callers” ascended the monument’s stairwell to the 100-foot level, followed by a “first responder” team.
  • Scenario 2: The Observation Deck Under Load
    The final test simulated an active shooter scenario during peak crowd congestion. Three “callers” ascended to the 500-foot observation deck just before the fireworks display began.

The Results: A New Standard in Geolocation
The conclusions from this comprehensive testing are clear and transformative for public safety:

  • Pinpoint Z-Axis Accuracy: By integrating height data, emergency responders can pinpoint a caller’s location in three dimensions, drastically improving response times and accuracy, both above and below ground. NextNav’s service independently exceeds the FCC’s mandate for ±3 meter vertical location accuracy.
  • Unwavering Resilience: The service performed reliably during a mass gathering where cellular services were heavily stressed, proving its dependability when it’s needed most.

Powerful 3D Visualization: The ability to visualize the location of callers and responders on a 3D map is an invaluable tool, providing incident commanders with immediate, intuitive situational awareness.

This exercise was more than a technology demonstration; it was a validation of the future of emergency response. The ability to precisely locate someone vertically inside a building is no longer a wish—it’s a reality.