Assured PNT for Critical Infrastructure: An Operator Playbook for GNSS Resilience
Assured PNT for critical infrastructure means a network keeps trustworthy position and timing even when GNSS is degraded, jammed or spoofed. That is achieved at the receiver: multi-constellation, multi-frequency GNSS with interference mitigation (Septentrio AIM+), integrity monitoring (RAIM+), continuous interference logging, and a disciplined holdover clock for time-critical systems. Power, water, telecom and transport operators do not need a new satellite system — they need receivers that degrade gracefully and report honestly.
Talk to a GNSS engineer about your network’s resilience requirements.
Request a quote → | Tell us your threat environment, interface and quantity and you will get a configuration, not a catalogue page.
What does assured PNT mean for a network operator?
Assured PNT is an operating requirement, not a product, and it breaks into four testable questions:
- Can the system detect interference or spoofing, instead of silently trusting bad data?
- Can it keep working at reduced accuracy while the interference lasts?
- Can it hold time long enough to ride through an outage?
- Can you prove afterwards what happened, from logged interference and integrity data?
A receiver that only outputs a fix answers none of these. One with interference monitoring, integrity flags and holdover outputs answers all four — the difference between consumer-grade GNSS and infrastructure-grade. The anti-jamming and anti-spoofing GNSS platforms Eview integrates for these deployments are built on Septentrio modules for exactly this reason.
Where do GNSS-dependent operations actually break?
Jamming is no longer exotic: cheap wideband jammers sold as privacy devices put automotive-grade interference into urban and highway environments for hours at a time, and spoofing has moved from research demonstrations to commercially available transmitters. The result is rarely a dramatic outage — it is a slow loss of trust: a drifting clock, a position 30 m out, a timestamp that no longer reconciles with the rest of the network.
| Threat | What fails first | Receiver-level mitigation |
|---|---|---|
| Broadband or swept jamming | Lock loss, PPS drift, RTK fix drop-out | AIM+ adaptive and notch filtering; multi-frequency (L1/L2/L5, E1/E5, B1/B2) |
| Spoofing / meaconing | Wrong position or time accepted as valid | RAIM+ integrity monitoring; spectrum monitoring that flags the anomaly |
| Multipath at substations, ports, tunnels | Centimetre accuracy erodes silently | Multi-frequency processing, multipath mitigation, disciplined antenna siting |
| Extended timing outage | Phase synchronisation slips | Oscillator holdover; 1PPS and PTP/NTP outputs with alarm flags |
| Constellation or ionospheric event | Poor geometry, intermittent fix | Simultaneous GPS, GLONASS, Galileo, BeiDou tracking (plus QZSS/NavIC) |
Which receiver capabilities deliver resilience?
Insist on these in the specification — each can be answered with data, not adjectives:
- Interference mitigation, not just filtering. AIM+ monitors the in-band spectrum continuously and applies adaptive filtering, so a jammer appearing mid-shift is suppressed rather than tolerated.
- Integrity monitoring. RAIM+ flags anomalous measurements instead of feeding them into the navigation solution — that flag is what lets a control system fall back safely.
- Multi-frequency, multi-constellation. Four constellations across three frequencies keep enough usable measurements when part of the band is unusable.
- Timing outputs and holdover. Substation and telecom sync needs 1PPS and PTP/NTP with defined holdover, not just NMEA — see GNSS timing for critical infrastructure.
- Exportable logs. Interference spectra, jamming indicators and integrity events must be provable after the incident.
In independent Jammertest trials, AIM+-equipped Septentrio receivers have held centimetre-level accuracy through continuous-wave, chirp and multi-tone jamming where conventional receivers lost RTK fix. Under interference that matters more than a clean-sky spec of 0.6 cm + 0.5 ppm horizontal RTK.
What does a realistic deployment look like?
Most operators harden the points where GNSS loss has consequences rather than replacing a network. Substation and telecom sites get one GNSS-disciplined clock feeding PTP to protection and sync equipment. Transport assets get hardened receivers where route integrity and timestamped position matter, as in rail and logistics GNSS applications, and field teams get rugged GNSS receiver boxes that stay on RTK fix where a handheld will not.
Assured PNT checklist: six questions before you buy
- Which functions lose money or safety margin in the first 60 seconds of GNSS loss?
- What is the RF threat environment — measured, not assumed?
- Can the receiver detect and report jamming and spoofing, in what exportable format?
- What holdover duration does your sync equipment need, with which oscillator?
- Which interfaces must it present — Ethernet, serial, 1PPS, PTP, NMEA, corrections?
- Who supports it locally, and what is the response path when a site goes down?
Frequently asked questions
Is GNSS jamming really a threat to utility and transport networks?
Yes, and mostly as a by-product rather than a targeted attack. Inexpensive jammers and nearby transmitters degrade GNSS over a wide radius, so timing and positioning systems suffer even when nobody intended to interfere. Operators usually notice it as intermittent sync alarms or unexplained position errors.
Can a GNSS receiver eliminate jamming and spoofing entirely?
No receiver survives an arbitrarily hostile RF environment. Receiver-level mitigation — AIM+ for interference, RAIM+ for integrity — extends that environment, detects what cannot be suppressed, and reports it instead of outputting a plausible wrong answer. That detection is what makes fallback work.
Do I need to replace my existing GNSS clock to improve resilience?
Usually not entirely. Most operators prioritise sites where loss has a direct consequence — main substations, core transport nodes, assets feeding synchronisation downstream — and retrofit those with an infrastructure-grade receiver while the rest of the estate stays as it is.
How do I get pricing for a resilient GNSS receiver configuration?
Configuration drives cost: OEM board or enclosed receiver, oscillator class for holdover, interface set and quantity. Share your environment and interfaces with our team for a configured quote with options priced explicitly — request a quote.
Next step
Assured PNT is a specification you can write down, test and document. Start with a survey of your real RF environment, then match receiver capability to it: interference mitigation, integrity monitoring, constellation diversity and honest holdover figures. Eview supplies and supports Septentrio-powered GNSS receivers and OEM boards for these deployments and can turn a resilience requirement into a concrete bill of materials.
Contact our engineering team at tina.ng@gnss-solutions.com or use the contact form to discuss your project.
