Navigation & sensor fusion

Navigation that works when GPS doesn’t.

Independent consulting on GNSS resilience, sensor fusion and navigation testing.

Book a resilience auditSee the research
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

Signal

GNSS jammed

no satellite fix

Fix

Position held

particle filter · terrain map

  • PhD research · GNSS-free navigation
  • Particle & Kalman filters
  • Fixed price · email-first

Services

Three ways we can help

Clear scope and a fixed price, agreed by email before any work starts.

01

GNSS resilience audit

Find out what breaks when GPS is jammed, spoofed or simply missing, and what to do about it.

Fixed price · about 2 weeks

02

Sensor fusion & filter design

Kalman and particle filters, IMU calibration and multi-sensor integration for drones, robots and vehicles.

Fixed scope or day rate

Free tools

Use them today

Live data, a self-check and hands-on demos. No sign-up needed.

Preview · illustrative data

UK GNSS interference map

Where GNSS is being disrupted over the UK, updated daily.

Self-check

PNT resilience check

Fourteen questions, a score and your first three actions.

Demos

Live demos

Jamming range, spoofing detection and clock holdover, in your browser.

How it works

  1. Send a short brief

    A few lines on your system, sensors and what’s worrying you. No calls needed.

  2. Get a fixed quote

    Scope, deliverables and price, back within two working days.

  3. Receive the work

    A clear report plus any code and test data. Yours to keep.

Isometric city of blocks with a drone flight path coloured by GNSS quality, running from good sky view through degraded stretches to a denied section, with a reflected satellite signal marked.
FIG. — Over a city, GNSS quality changes block by block; where the sky is blocked the drone leans on inertial and vision. Illustrative.

Sectors

Where we work

Drones & UAS

Drones

Losing GNSS mid-flight, compass trouble and multipath near structures.

Audits · fusion · testing

Maritime & ports

Maritime and ports

Spoofed positions at sea and port systems quietly running on GNSS time.

Reviews · audits · testing

Rail

Rail

Tunnels, cuttings and wheel slip, and positions you can put a safety case on.

Fusion design · testing

Timing & telecoms

Timing and telecoms

Holdover, hidden time dependencies and receivers that can be fooled.

Reviews · holdover tests

Logistics & fleets

Logistics and fleets

Trackers, tachographs and suppliers that all go blind at once.

Reviews · outage exercises

From the lab

Research & demos

Hands-on demos and published work on navigation without GNSS.

Demo

Spot the spoof

Watch a position get dragged away, and which checks catch it.

Papers

Publications

Selected papers on GNSS-free navigation, linked by DOI.

About

Who’s behind Bearing & Fix

Bearing & Fix is run by Dan Chadwick, a PhD researcher working on navigation without GNSS: particle filters, magnetic map matching and heading from polarised light.

We help companies outside the lab with practical engineering and the statistics to back it up. Based on the Wirral, working across the UK.

Based
Wirral, UK
Working
UK-wide, remote-first
Focus
GNSS-free navigation
Methods
Particle & Kalman filters
Pricing
Fixed, agreed by email

Have a navigation problem?

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

dan@bearingandfix.co.uk