About

We build navigation that works when GPS doesn’t.

Bearing & Fix is run by Dan Chadwick, a PhD researcher and software developer working on navigation without GNSS: particle filters, magnetic map matching and heading from polarised light. We bring that work to companies outside the lab.

  • Based on the Wirral
  • Working UK-wide
  • Email-first
Particle filter demoA cloud of position guesses spreads out over terrain contours while GNSS is unavailable, then closes in on the estimated route, which follows the true route.

Live demo · Particle filter · Illustrative

GNSS unavailable
  • true route
  • estimate
  • particles

Eryri · OS Terrain 50

Contains OS data © Crown copyright and database right 2026

What we do

Practical navigation engineering

Three kinds of work, each with a clear scope and a fixed price.

01

Resilience audits

What happens to your system when GPS is jammed, spoofed or simply missing.

02

Filter design

Kalman and particle filters, IMU calibration and multi-sensor fusion.

03

Testing & evaluation

Independent simulation and test campaigns with honest statistics.

Cross-section of a city skyline, a river with a vessel on the surface using satellite navigation, and a tunnel curving beneath the river where a vehicle relies on inertial navigation, odometry and beacons.
FIG. — Above the river the vessel has open sky; in the tunnel below, traffic relies on INS, odometry and beacons. Illustrative.

Background

How Bearing & Fix started

  1. {Year} — now

    PhD research: GNSS-free navigation

    {One or two sentences on your research: particle filters, magnetic map matching, polarised-light heading.}

  2. {Year} — now

    Software developer

    {Where and what you build. Web, data, embedded?}

  3. {Year}

    Founded Bearing & Fix

    Consulting on GNSS resilience, sensor fusion and navigation testing.

  4. {Year}

    {Degree or earlier role}

    {Short description.}

Research interests

What we think about

  • Particle filters
  • Kalman filtering
  • Magnetic map matching
  • Polarised-light heading
  • Inertial navigation
  • GNSS resilience
  • Sensor calibration
  • Uncertainty & statistics

How we work

What you can expect

Fixed prices

Clear scope and a price agreed by email before any work starts. No surprises.

Email-first

No sales calls needed. Send a short brief and get a quote within two working days.

Honest statistics

Results reported with uncertainty and the conditions they hold under, not just best cases.

Publications

Selected work

  • {Paper title}

    {Authors} · {Venue}, {Year}

    DOI →

  • {Paper title}

    {Authors} · {Venue}, {Year}

    DOI →

  • {Paper title}

    {Authors} · {Venue}, {Year}

    DOI →

All publications →

Want to work together?

Send a short brief and we’ll reply within two working days.

dan@bearingandfix.co.uk