GPS Spoofing Filter — hardware protection of UAVs against GPS spoofing
Problem
Enemy electronic warfare systems transmit false GPS coordinates. The flight controller takes them for real. Result: the drone deviates from the route, flies to an enemy position or crashes. Equipment worth thousands of dollars is lost and the combat mission is disrupted.
No software solution can reliably fix this — a separate hardware module is needed that analyzes the GPS signal before it reaches the flight controller.
Solution
GPS Spoofing Filter is an STM32 microcontroller that physically stands between the GPS receiver and the flight controller. It analyzes satellite data 460800 times per second and decides whether to transmit or block.
When the GPS is clean — the data passes through, the drone flies normally.
When spoofing is detected, the GPS stream is blocked, the controller switches to dead-reckoning (inertial navigation using IMU, compass and airspeed). The drone continues to fly, rather than flying to false coordinates.
What EW systems does it protect against
The filter detects spoofing and jamming based on physical signal anomalies, rather than on signatures of specific systems. This means protection against any EW system — existing and future.
Tested against:
GPS spoofing GNSS jamming Other
Ukrainian Lima, Patelnya, Pokrova Bukovel, Note, Damba, Enclave Kulbaba, PARASOL, Piranha
Russian Pole-21, Shypivnyk-Aero R-330Zh Zhitel, Borisoglebsk-2 Krasukha, Leer-3, Repellent-1
Belarusian — Thunderstorm —
6 levels of protection
Position jump — sharp change in coordinates or unrealistic speed between fixes
Loss of fix / few satellites — GPS disappears or the number of satellites drops below the threshold
SNR anomaly — many satellites with suspiciously equal signal strength (classic sign of a spoofer)
Altitude anomaly — altitude jump, unrealistic gain speed, GPS vs barometer discrepancy
EKF check — Kalman navigation filter on the controller reports an unhealthy state
Automatic recovery — return to GPS only after confirming stability signal
Key benefits
Reduces equipment losses. The drone will not fly to false coordinates. When spoofing, it switches to inertial navigation and continues the mission or returns to base.
Works autonomously. Does not require operator intervention during flight. Turned on and forgot.
Does not require changing the controller firmware. Only minimal configuration of serial ports in ArduPilot. Compatible with ArduPilot 4.4.1+ (Copter, Plane, Rover).
Supports u-blox and UM980/UM981. The two most common GPS receivers for UAVs. UM980 is recommended for areas with intensive electronic warfare.
Encrypted firmware. Each board has a unique encryption key. The firmware cannot be copied to another board, read through the debug port, or forged. Signature Ed25519.
Cloud dashboard. Download spoofing logs via USB-C, view events on a map, analyze attack patterns in a browser.
Update via USB-C. No ST-Link or additional programmer required. Connected the cable - updated the firmware - downloaded the logs.
Compact. 53 × 23 mm, BlackPill form factor. Easily mounted inside any frame.
Combat experience. Deployed in the field for over a year. Tested in real EW conditions.
Technical specifications
Microcontroller STM32H743
GPS input u-blox (M8/M9/M10/F9/F10) or UM980/UM981/UM982 or Septentrio Mosaic X5 (AsteRX,
Interface with DroneCAN controller
GPS transmission DroneCAN or UART @ 460800 baud
Support for ArduPilot 4.4.4+ controllers
Flash memory protection RDP Level 1 (read protection)
Firmware updates Encrypted (per-device), signed (Ed25519)
Power supply 5 V
Dimensions 80x50x20 mm
What's in the box
Board with flashed firmware
License key (1 key = 1 board)
Access to the spoofing cloud dashboard
Free firmware updates
Documentation in Ukrainian and English
Installation in 15 minutes
Connect 6 wires between GPS receiver, filter and controller
Configure 2 serial ports in Mission Planner
Done — filter works automatically
Key benefits
DroneCAN, status screen, logs in mission planner
Hardware protection against GPS spoofing — blocks false coordinates TO controller
Tested against Lim, Patelnya, Pokrov, Pole-21, Bukovel, R-330Zh and 20+ EW systems
6 independent algorithms for real-time spoofing detection
Automatic switch to dead-reckoning during attack — drone does not fly to false coordinates
Encrypted firmware with a unique key for each board — do not copy, do not hack
Updates and logs via USB-C — no additional equipment
Cloud dashboard with a map of spoofing events and analytics
Installation in 15 minutes, does not require ArduPilot firmware changes
Supports u-blox and UM980/UM981/UM982 receivers
Compact: in a 80 x 50 x 30 mm case
Over 1 year of combat experience in an active EW area
Free firmware updates and support
Docs:
https://gps.airdroper.org
