Two passive modules. Zero RF emissions.
Works over ocean, under jamming, at night.
Plug into any UAV or USV via MAVLink.
GPS is jammed in every contested zone.
Map matching fails over open ocean.
Existing alternatives are heavy, expensive, or detectable.
We use the sky itself as a reference.
Camera points at zenith. OpenCV detects stars
as bright blobs. Grid search sweeps 0°→360°,
projects the Hipparcos catalog (2,816 stars, mag<5.5)
and counts matches to find the best yaw estimate.
IMU alone drifts in yaw over time. Star tracker
provides yaw corrections every 30 seconds —
position is computed via dead reckoning from IMU.
Skylight is polarized in a pattern centered on the sun.
6 UV sensors at different angles measure this pattern.
Grid-search algorithm finds the heading that best
explains all sensor readings simultaneously.
Polarization compass continuously corrects IMU heading
drift during the day. Position error stays bounded
across the full flight without any map data —
works over ocean where map matching fails.
Live simulation of GPS jamming.
Watch how each algorithm responds in real time.