Navigation without GPS
Draper builds navigation systems that keep working when satellite signals don't. Our inertial sensors, estimation algorithms, and alternative navigation methods hold position and attitude through jamming, spoofing, deep water, and deep space — environments where GPS is denied, degraded, or was never available.
The signal is the weakest link.
Almost everything that moves now assumes a satellite is telling it where it is. That assumption breaks in more places than most systems account for — under water, under a jungle canopy, in contested airspace, on the surface of another planet. It also breaks on purpose. A signal you can receive is a signal someone can jam or imitate.
We've worked on this since the beginning. Draper's founding work was inertial guidance — working out position from a system's own motion instead of an outside reference — and that line runs straight into the sensors, filters and flight software we build now.
What's changed is the range. The same question now has to be answered for a submarine, a satellite, a lunar lander and something you carry, each with its own limits on power, size and how much error it can survive.
How we approach it
We build the sensor, not just the system
Accuracy is bounded by the physics of the measuring device. We develop inertial sensors in-house rather than integrating someone else's, so the ceiling is ours to move.
Every input is imperfect, so fuse them
No single reference can be trusted on its own. Estimation and sensor fusion combine inertial data with terrain, celestial, magnetic and signal-of-opportunity references, weighting each by how much it deserves to be believed at that moment.
It has to survive the environment it's for
An algorithm that works in simulation isn't a navigation system. Packaging, thermal behavior, radiation tolerance and qualification testing decide whether any of it reaches the field.
Where it's applied
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Strategic Systems
Undersea and sea-based guidance
Position held over long submerged transits, where no external reference is available for the duration of the mission.
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Space Systems
Lunar descent and landing
Terrain-relative navigation and autonomous hazard avoidance for landing on a surface with no atmosphere and no GPS constellation.
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Electronic Systems
Miniaturized inertial measurement
MEMS-scale devices that bring navigation-grade performance into size, weight, and power budgets that were previously out of reach.
Who works on this
Guidance, navigation and control
Systems engineers who own the end-to-end behavior, from sensor error budget to flight software.
Device physics and microfabrication
Researchers building the inertial sensors themselves, in Draper's own fabrication and test facilities.
Estimation and autonomy
Algorithm developers working on filtering, fusion, and decision-making under uncertainty — several of them Draper Scholars.
Bring us the version of this that doesn't work yet.
We pick things up where the existing approach runs out — a research question, or a system that has to be qualified and delivered.