March 13, 2025

111. Tactical Tech: How Smartphones are Countering Jamming in Ukraine with Dr. Sean Gorman

28 minutes

“The hope is that we can begin to profile what the capabilities of the jammer are that we’re seeing out in the field with enough measurements from enough devices”

[Editor’s Note: In last week’s post, Sherman L. Barto posited a fictional intelligence (FICINT) scenario detailing China’s swift victory over Taiwan and the United States — achieved in part by the People’s Liberation Army’s use of

“… jam-resistant swarms utiliz[ing] permissioned blockchain encryption and … onboard AI adjust[ing] Software Defined Radio (SDR) receivers in real time to ignore interference that does not transmit with proper encryption and authentication. The loss of GNSS satellite navigation was assumed by PLA military planners and is replaced with a ship-based Long Range Navigation (LORAN) system providing the location of the three PLAN aircraft carriers to UAVs which is then paired with UAV computer vision trained on detailed maps of Taiwan to recognize where they are. Each UAV transmits a location tag every second to each adjacent node in the swarm, enabling precision location within 20 meters. The one pulse per second geolocation tags perform double duty as a network timing protocol, ensuring all PLA networks remain in synch despite the loss of GNSS timing.”

A U.S. Army maneuver Brigade Combat Team (BCT) has over 2,500 pieces of equipment dependent on space-based assets for Positioning, Navigation, and Timing (PNT) — precision strikes and the convergence of massed fires depend on accurate and resilient PNT data. However, as we’ve seen in Russia’s on-going war in Ukraine, access to this PNT data is increasingly being disrupted or spoofed by Electronic Warfare (EW) jammers.

Today’s The Convergence podcast welcomes Dr. Sean Gorman, CEO and co-founder of Zephr.xyz, to discuss how his company is “crowdsourcing [GPS] measurements across a bunch of phones to get a better version of reality by looking at more satellites and getting more measurements.” Zephr is also harnessing this capability as a counter-EW jamming capability, turning everyone with a cellphone into a sensor to detect, identify, catalog, and locate these emitters. These capabilities, conceptually proven in Ukraine, may soon be tested in Taiwan against our most capable adversary — the People’s Liberation Army — Enjoy!]

Sean Gorman is the CEO and co-founder of Zephr.xyz, a developer of next-gen networked positioning technologies. Gorman has a more than 20-year background as a researcher, entrepreneur, academic, and subject matter expert in the field of geospatial data science and its national security implications. He is the former engineering manager for Snap’s Map team, former Chief Strategist for ESRI’s DC Development Center, founder of Pixel8earth, GeoIQ, and Timbr.io, and held other senior positions at Maxar and iXOL. Gorman served as a subject matter expert for the Department of Homeland Security’s Critical Infrastructure Task Force and Homeland Security Advisory Council, and he’s been awarded eight patents. He is also a former research professor at George Mason University.

In our latest episode of The Convergence podcast, Army Mad Scientist sits down with Dr. Sean Gorman to discuss countering Russian Electronic Warfare (EW) jammers, how he came to work with the Ukrainian military, and commercial solutions in a Global Positioning System (GPS)-denied environment. The following bullet points highlight key insights from our conversation.

Zephr builds Global Navigation Satellite System (GNSS) technologies to improve and enhance Precision, Navigation, and Timing (PNT) accuracy and resiliency, while also providing countermeasure capabilities to help detect adversarial GNSS jamming/spoofing and locate their emitters. Their concept utilizes ensemble optimization — taking measurements from geographically dispersed devices, such as mobile phones, pinging their GPS measurements to satellites, then using a software server to calculate error corrections, which are then sent back to the phones and used to improve each device’s positioning accuracy — to locally determine positioning. This capability provides a democratized, inexpensive method to mitigate EW jamming of PNT.

Citing their challenges in executing battlefield medical evacuation and logistics operations in a GPS-denied environment, a group of Ukrainian soldiers contacted Zephrdirectly for assistance in mitigating Russian jamming. Using a few Android devices to begin collecting data, additional phones provided further resiliency to positioning, the ability to map the jammed area, and the possibility of calculating the signals’ angles of arrival to determine the emitter’s location.

In the future, the intent is to profile the capabilities of distinct jammer types based on collected data. Starting with data collected from Ukrainian jammers, the group calibrates and profiles signals to determine what the area of effect will look like for each emitter type, then consolidates the data into baseline calibration data. They hope to use this concept to compare this data to Russian jammers’ capabilities — enabling them to calculate the distance from the emitter and determine what kind of signal and disruption effects they’re getting.

This capability uses off-the-shelf Android devices, but any GNSS-receiving device could be used. Android devices were easy to test because of their ubiquity and the ease with which they can be delivered around the world. This will make further testing in INDOPACOM with our Taiwanese partners possible — the idea is to turn every phone across the island into a sensor that can detect EW events.

One of the keys to succeeding in an alt-PNT environment is a layered approach, as the integration of GNSS with commercial and military capabilities is critical. The Ukrainians struggled to gain independence from GPS. Zephr is currently working with Air Force Research Labs to provide this capability in theTactical Assault Kit (TAK) ecosystem.

Stay tuned to the Mad Scientist Laboratory for our next episode of The Convergence on 27 Mar 2025, when Army Mad Scientist sits down with returning guest Dr. Billy Barry to discuss his latest invention — an AI-enabled digital wargame! We tested this capability with two of the most experienced TRADOC G-2 wargamers and get their thoughts on how it performed.

If you enjoyed this post, check out TRADOC Pamphlet 525-92, The Operational Environment 2024-2034: Large-Scale Combat Operations, laying out the 12 LSCO Conditions and 5 LSCO Implications of the Operational Environment, several of which expand on aspects of this podcast and blog post (e.g., Transparent Battlefield and Mass vs. Precision).

Explore the TRADOC G-2‘s Operational Environment Enterprise web page, brimming with authoritative information on the Operational Environment and how our adversaries fight, including:

Our China Landing Zone, full of information regarding our pacing challenge, including ATP 7-100.3, Chinese Tactics, BiteSize China weekly topics, People’s Liberation Army Ground Forces Quick Reference Guide, and our thirty-plus snapshots captured to date addressing what China is learning about the Operational Environment from Russia’s war against Ukraine (note that a DoD Common Access Card [CAC] is required to access this last link).

Our Russia Landing Zone, including the BiteSize Russia weekly topics. If you have a CAC, you’ll be especially interested in reviewing our weekly RUS-UKR Conflict Running Estimates and associated Narratives, capturing what we learned about the contemporary Russian way of war in Ukraine over the past two years and the ramifications for U.S. Army modernization across DOTMLPF-P.

Our Iran Landing Zone, including the latest Iran OE Watch articles, as well as the Iran Quick Reference Guide and the Iran Passive Defense Manual (both require a CAC to access).

Our Running Estimates SharePoint site (also requires a CAC to access), containing our monthly OE Running Estimates, associated Narratives, and the 2QFY24, 3QFY24, 4QFY24, and 1QFY25 OE Assessment TRADOC Intelligence Posts (TIPs).

Then review the following related Mad Scientist Laboratory content addressing PNT, EW, and the transparent battlefield:

LSCO, PNT, and the Space Domain, by CPT Matthew R. Bigelow

Space: Challenges and Opportunities

Insights from Ukraine on the Operational Environment and the Changing Character of Warfare

Russia-Ukraine Conflict: Sign Post to the Future (Part 1), by Kate Kilgore

Operation Northeast Monsoon: The Reunification of Taiwan

China: “New Concepts” in Unmanned Combat and Cyber and Electronic Warfare

Future Dynamics of Warfare: Everyone is a Player, Everything is a Target

Warfare in the Parallel Cambrian Age, by Chris O’Connor

Disclaimer: The views expressed in this blog post do not necessarily reflect those of the U.S. Department of Defense, Department of the Army, Army Futures Command (AFC), or Training and Doctrine Command (TRADOC).

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By The Army Mad Scientist Initiative