AlgoNav Rail
High-precision GNSS/INS/Odometry positioning for track geometry measurement, train localization, and rail infrastructure monitoring -- powering track recording vehicles and digital rail infrastructure across Europe with gap-free trajectories through tunnel outages.
Why AlgoNav for Rail?
Reliable train positioning software engineered for the demanding requirements of modern railway operations and track geometry measurement campaigns.
Track Geometry Measurement
Precise measurement of railway track alignment, gauge, cant, and longitudinal level for proactive maintenance planning. Our GNSS/INS/Odometry trajectory processing delivers the centimeter-level accuracy required to reference all geometry parameters in the national coordinate system and support EN 13848 quality workflows.
Continuous Train Localization
Tightly-coupled GNSS/INS with inertial odometry maintains continuous high-accuracy positioning through tunnels, underpasses, and station environments where GNSS signals are blocked or degraded. No gaps in your trajectory, even on the most challenging rail corridors.
Asset Georeferencing & Clearance Gauging
Accurate georeferencing of signals, switches, mileposts, and infrastructure elements for digital asset inventories. Combined with LiDAR, the same trajectory enables structure gauging runs and clearance profile generation for rolling stock compatibility assessments.
Moving Virtual Reference Station
Track recording campaigns span hundreds of kilometers — far beyond the range of a single base station. AlgoNav generates a moving virtual reference station along the entire corridor for consistent high accuracy. Reference station data from GNSS correction service providers is auto-fetched, so operators need not source or manage any base station data themselves.
Rail-Specific Motion Constraints
Standard non-holonomic constraints model road vehicles with a fixed rear axle. Rail vehicles are fundamentally different — bogies rotate relative to the car body and wheels follow fixed track geometry through curves. AlgoNav implements dedicated rail motion constraints that model these bogie-on-track kinematics. Combined with precise odometry integration — wheel encoder data modeled as true incremental distance observations — this prevents trajectory drift even through very long tunnels with up to an hour of driving time, or during extended standstills at covered stations where GNSS can be unavailable for hours.
Compatible with Any Track Recording Vehicle Hardware
Track recording vehicles across Europe use different GNSS and IMU hardware from different manufacturers and generations. AlgoNav processes data from virtually any sensor with an open or documented format — one processing engine for your entire fleet, whatever hardware it carries.
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RTK vs PPK in Rail Surveying
Track geometry measurement and railway corridor surveys require gap-free, centimeter-level trajectories through tunnels and cuttings. How do real-time and post-processed approaches compare?
Real-Time (RTK)
Corrections during measurement runs
- GNSS completely blocked in tunnels, station halls, and deep cuttings — RTK cannot bridge these gaps
- Catenary systems and metal structures cause severe multipath that degrades real-time fix quality
- IMU alignment requires static warmup before each measurement run — costly idle time that is often impractical on tightly scheduled track possessions
- Forward-only filtering means accuracy degrades immediately at tunnel entry with no recovery until exit
- Real-time sensor fusion requires all data links between GNSS, IMU, and odometer to work continuously — operationally demanding on scheduled measurement runs
Post-Processed (PPK / PPP)
Post-processed trajectories with tunnel bridging
- Record raw GNSS/IMU/odometer data during scheduled runs — no dependency on correction streams
- Iterative optimal smoothing bridges tunnel outages seamlessly using tightly coupled inertial data
- Multipath from catenary and metal structures detected and rejected through multi-pass estimation
- Centimeter-level accuracy for track alignment, gauge, cant, and longitudinal level measurements
- Each sensor simply logs data independently — no inter-sensor data links required, much simpler to operate on track recording vehicles
- No static IMU alignment needed — orientation is resolved from the data, recording can begin mid-journey
Instant Post-Processing: Results Within Minutes!
With a processing server installed onboard the measurement train, AlgoNav delivers fully post-processed trajectories within minutes of completing a run. Reference station data is auto-fetched — no manual intervention needed. This gives track engineers immediate insight into measurement quality so re-inspection of critical sections can be decided on the spot, before leaving the track possession.
Challenges We Solve
Railway environments present unique positioning challenges that standard GNSS processing cannot handle. AlgoNav's algorithms are specifically designed to overcome these obstacles.
Tunnel & Station GNSS Outages
Measurement trains regularly traverse tunnels lasting up to an hour of driving time, and often stand stationary under covered station roofs for hours — all without any GNSS signal. AlgoNav's tightly-coupled INS and odometry integration maintains centimeter-level trajectory continuity throughout, so no segment of your measurement record is lost.
Dense Railway Environments
Urban rail corridors, deep cuttings, and routes alongside electrified infrastructure create heavy multipath from metal structures and catenary systems plus signal obstruction. AlgoNav's robust GNSS processing handles these degraded signal conditions through advanced outlier detection, multi-constellation tracking, and multipath mitigation, ensuring reliable positioning even in the most challenging rail infrastructure monitoring scenarios.
No Alignment Required
Real-time INS systems require 10–20 minutes of static warmup before each run for IMU alignment — idle time that is often simply not available on tightly scheduled track possessions. AlgoNav resolves initial orientation directly from the logged data during post-processing. No static warmup, no gyro-compassing hardware — data recording can begin the moment the train starts moving.
Long-Distance Corridor Processing
Measurement campaigns spanning hundreds of kilometers cannot rely on a single base station or a continuous RTK link — mobile internet drops are common and cause data gaps in real-time solutions. AlgoNav auto-fetches reference station data from GNSS correction service providers and generates a moving virtual reference station along the entire corridor, enabling reliable ambiguity resolution where real-time fixes would have failed.
Fleet-Scale Data Efficiency
When entire fleets of track recording vehicles operate around the clock, data volumes grow rapidly. AlgoNav's cloud processing provides the compute power to handle these volumes efficiently, with a hierarchical structure where campaigns, routes, and individual runs are organized and traceable — turning weeks of manual post-processing into automated batch runs that complete within minutes.
Instant Post-Processing
Some inspection workflows require immediate results — for example, when a track segment shows potential defects that may require re-inspection before the next scheduled run. AlgoNav can process data on an onboard server or via cloud upload immediately after a run completes, delivering full-accuracy trajectories within minutes so operational decisions can be made on the spot.
Let's Talk
Discover how our GNSS/INS positioning solutions support railway operators, infrastructure managers, and track recording vehicle manufacturers across Europe.