A Primer for Aviation Stakeholders
By Dr. Matthias Schäfer, CEO, SeRo Systems
In today’s aviation ecosystem, Global Navigation Satellite Systems (GNSS), especially GPS, have become indispensable for navigation, timing, and surveillance. But what happens when these signals are disrupted? The answer is often confusion, misinterpretation, or operational disruption.
A Primer for Aviation Stakeholders
By Dr. Matthias Schäfer, CEO, SeRo Systems
In today’s aviation ecosystem, Global Navigation Satellite Systems (GNSS), especially GPS, have become indispensable for navigation, timing, and surveillance. But what happens when these signals are disrupted? The answer is often confusion, misinterpretation, or operational disruption.
A Primer for Aviation Stakeholders
By Dr. Matthias Schäfer, CEO, SeRo Systems
In today’s aviation ecosystem, Global Navigation Satellite Systems (GNSS), especially GPS, have become indispensable for navigation, timing, and surveillance. But what happens when these signals are disrupted? The answer is often confusion, misinterpretation, or operational disruption.
Over the last few years, GNSS Radio Frequency Interference (RFI) has been making headlines around the world. With high profile incidents in the news every day, it's become clear that intentional interference is no longer theoretical — it's operational. Recognizing the growing threat, aviation authorities like EASA and ICAO have issued new guidance, calling on operators and regulators to enhance monitoring, improve crew training, and invest in more resilient positioning, navigation and timing (PNT) capabilities.
This article will help you cut through the noise and bring clarity to GNSS RFI monitoring — starting with the basics. Welcome to our 3-part series on GNSS RFI monitoring for the aviation and national security industry.
Over the last few years, GNSS Radio Frequency Interference (RFI) has been making headlines around the world. With high profile incidents in the news every day, it's become clear that intentional interference is no longer theoretical — it's operational. Recognizing the growing threat, aviation authorities like EASA and ICAO have issued new guidance, calling on operators and regulators to enhance monitoring, improve crew training, and invest in more resilient positioning, navigation and timing (PNT) capabilities.
This article will help you cut through the noise and bring clarity to GNSS RFI monitoring — starting with the basics. Welcome to our 3-part series on GNSS RFI monitoring for the aviation and national security industry.
Over the last few years, GNSS Radio Frequency Interference (RFI) has been making headlines around the world. With high profile incidents in the news every day, it's become clear that intentional interference is no longer theoretical — it's operational. Recognizing the growing threat, aviation authorities like EASA and ICAO have issued new guidance, calling on operators and regulators to enhance monitoring, improve crew training, and invest in more resilient positioning, navigation and timing (PNT) capabilities.
This article will help you cut through the noise and bring clarity to GNSS RFI monitoring — starting with the basics. Welcome to our 3-part series on GNSS RFI monitoring for the aviation and national security industry.
What is GNSS RFI... and Why Should You Care?
GNSS RFI refers to any unwanted radio frequency signals that disrupt or degrade the normal functioning of GNSS receivers, such as those used for GPS, Galileo, GLONASS, or BeiDou. Aircraft rely on GNSS (mostly GPS) for navigation, approach procedures, and surveillance systems like ADS-B, making them particularly vulnerable to interference. When RFI disrupts GNSS signals, it can compromise key aircraft systems used for navigation, surveillance, leading to safety concerns and degraded situational awareness.
GNSS Radio Frequency Interference (RFI) comes in two major forms:
- Jamming – A radio transmitter, typically on the ground, floods the GPS frequency band with noise, causing GNSS receivers to lose signal altogether.
- Spoofing – A more sophisticated attack where a transmitter mimics GNSS signals, tricking receivers into calculating incorrect positions or timing.
For aviation stakeholders — including Air Navigation Service Providers (ANSPs), airport operators, and regulators — these threats are more than technical nuisances. Jamming can disrupt navigation or GNSS-based approach procedures, while spoofing may additionally lead to false aircraft positions being reported to air traffic controllers or onboard systems, with potentially serious consequences.
What is GNSS RFI... and Why Should You Care?
GNSS RFI refers to any unwanted radio frequency signals that disrupt or degrade the normal functioning of GNSS receivers, such as those used for GPS, Galileo, GLONASS, or BeiDou. Aircraft rely on GNSS (mostly GPS) for navigation, approach procedures, and surveillance systems like ADS-B, making them particularly vulnerable to interference. When RFI disrupts GNSS signals, it can compromise key aircraft systems used for navigation, surveillance, leading to safety concerns and degraded situational awareness.
GNSS Radio Frequency Interference (RFI) comes in two major forms:
- Jamming – A radio transmitter, typically on the ground, floods the GPS frequency band with noise, causing GNSS receivers to lose signal altogether.
- Spoofing – A more sophisticated attack where a transmitter mimics GNSS signals, tricking receivers into calculating incorrect positions or timing.
For aviation stakeholders — including Air Navigation Service Providers (ANSPs), airport operators, and regulators — these threats are more than technical nuisances. Jamming can disrupt navigation or GNSS-based approach procedures, while spoofing may additionally lead to false aircraft positions being reported to air traffic controllers or onboard systems, with potentially serious consequences.
What is GNSS RFI... and Why Should You Care?
GNSS RFI refers to any unwanted radio frequency signals that disrupt or degrade the normal functioning of GNSS receivers, such as those used for GPS, Galileo, GLONASS, or BeiDou. Aircraft rely on GNSS (mostly GPS) for navigation, approach procedures, and surveillance systems like ADS-B, making them particularly vulnerable to interference. When RFI disrupts GNSS signals, it can compromise key aircraft systems used for navigation, surveillance, leading to safety concerns and degraded situational awareness.
GNSS Radio Frequency Interference (RFI) comes in two major forms:
- Jamming – A radio transmitter, typically on the ground, floods the GPS frequency band with noise, causing GNSS receivers to lose signal altogether.
- Spoofing – A more sophisticated attack where a transmitter mimics GNSS signals, tricking receivers into calculating incorrect positions or timing.
For aviation stakeholders — including Air Navigation Service Providers (ANSPs), airport operators, and regulators — these threats are more than technical nuisances. Jamming can disrupt navigation or GNSS-based approach procedures, while spoofing may additionally lead to false aircraft positions being reported to air traffic controllers or onboard systems, with potentially serious consequences.
Aviation Safety's Blind Spot?
Most ANSPs already operate comprehensive monitoring systems for the infrastructure they manage: radar surveillance, communication links, navigation systems, and more. Yet GNSS — arguably one of the most important systems in modern aviation — is often trusted blindly. There is little to no visibility into whether GPS signals are degraded, jammed, or spoofed in real time.
This blind spot leaves a critical gap in situational awareness. Without active GNSS RFI monitoring, an ANSP may not even know aircraft are subject to interference until pilots report problems or there is an incident. This problem is additionally amplified with pilot reporting fatigue being high when it comes to GNSS-related issues. But even when pilots report GPS issues, ANSPs typically have no good way to verify the nature or extent of the problem.
Aviation Safety's Blind Spot?
Most ANSPs already operate comprehensive monitoring systems for the infrastructure they manage: radar surveillance, communication links, navigation systems, and more. Yet GNSS — arguably one of the most important systems in modern aviation — is often trusted blindly. There is little to no visibility into whether GPS signals are degraded, jammed, or spoofed in real time.
This blind spot leaves a critical gap in situational awareness. Without active GNSS RFI monitoring, an ANSP may not even know aircraft are subject to interference until pilots report problems or there is an incident. This problem is additionally amplified with pilot reporting fatigue being high when it comes to GNSS-related issues. But even when pilots report GPS issues, ANSPs typically have no good way to verify the nature or extent of the problem.
Aviation Safety's Blind Spot?
Most ANSPs already operate comprehensive monitoring systems for the infrastructure they manage: radar surveillance, communication links, navigation systems, and more. Yet GNSS — arguably one of the most important systems in modern aviation — is often trusted blindly. There is little to no visibility into whether GPS signals are degraded, jammed, or spoofed in real time.
This blind spot leaves a critical gap in situational awareness. Without active GNSS RFI monitoring, an ANSP may not even know aircraft are subject to interference until pilots report problems or there is an incident. This problem is additionally amplified with pilot reporting fatigue being high when it comes to GNSS-related issues. But even when pilots report GPS issues, ANSPs typically have no good way to verify the nature or extent of the problem.
What GNSS RFI Monitoring Is — and What It's Not
GNSS RFI monitoring refers to systems that continuously detect interference affecting GNSS services in a specific location or region.
Especially in aviation, the goal isn't just to observe anomalies after the fact but to establish uninterrupted situational awareness that supports immediate operational response and long-term mitigation planning.
GNSS RFI monitoring is the only infrastructure-level, short-term solution that provides real-time visibility into GNSS interference events as they unfold, across a defined airspace or region.
It's also important to understand what GNSS RFI monitoring is not:
- It is not the same as onboard mitigation, such as multi-constellation or multi-frequency receivers, advanced antennas that resist jamming, or cryptographic signal authentication (e.g., Galileo OS-NMA). These are important — but they're aircraft equipment-specific and will take years or decades to become widely adopted in civil aviation.
- It is not interference hunting. While interference hunting tools (like mobile direction-finding equipment or measurement flights) can help localize an interferer, they require manual deployment and only work after a problem has been reported or detected by other means. They are reactive by nature — not a monitoring solution.
- It is also not GNSS performance monitoring, such as systems built for GNSS augmentation or RTK services. These are typically designed to detect signal degradation from natural causes or system faults, not malicious interference. They may not detect jamming or spoofing, and they rarely provide the real-time visibility or aviation-specific context required for effective RFI monitoring.
In the context of aviation, GNSS RFI monitoring typically focuses on two critical areas:
- Ground-based monitoring near infrastructure, such as airports or CNS systems that rely on GNSS, particularly for time synchronization.
- Airspace monitoring, especially in regions where aircraft may be exposed to interference, such as near conflict zones, border areas, or high-risk air corridors.
These two domains, ground and airspace, require different monitoring strategies, but both are essential to maintaining safe, resilient aviation operations in an increasingly interference-prone GNSS environment.
What GNSS RFI Monitoring Is — and What It's Not
GNSS RFI monitoring refers to systems that continuously detect interference affecting GNSS services in a specific location or region.
Especially in aviation, the goal isn't just to observe anomalies after the fact but to establish uninterrupted situational awareness that supports immediate operational response and long-term mitigation planning.
GNSS RFI monitoring is the only infrastructure-level, short-term solution that provides real-time visibility into GNSS interference events as they unfold, across a defined airspace or region.
It's also important to understand what GNSS RFI monitoring is not:
- It is not the same as onboard mitigation, such as multi-constellation or multi-frequency receivers, advanced antennas that resist jamming, or cryptographic signal authentication (e.g., Galileo OS-NMA). These are important — but they're aircraft equipment-specific and will take years or decades to become widely adopted in civil aviation.
- It is not interference hunting. While interference hunting tools (like mobile direction-finding equipment or measurement flights) can help localize an interferer, they require manual deployment and only work after a problem has been reported or detected by other means. They are reactive by nature — not a monitoring solution.
- It is also not GNSS performance monitoring, such as systems built for GNSS augmentation or RTK services. These are typically designed to detect signal degradation from natural causes or system faults, not malicious interference. They may not detect jamming or spoofing, and they rarely provide the real-time visibility or aviation-specific context required for effective RFI monitoring.
In the context of aviation, GNSS RFI monitoring typically focuses on two critical areas:
- Ground-based monitoring near infrastructure, such as airports or CNS systems that rely on GNSS, particularly for time synchronization.
- Airspace monitoring, especially in regions where aircraft may be exposed to interference, such as near conflict zones, border areas, or high-risk air corridors.
These two domains, ground and airspace, require different monitoring strategies, but both are essential to maintaining safe, resilient aviation operations in an increasingly interference-prone GNSS environment.
What GNSS RFI Monitoring Is — and What It's Not
GNSS RFI monitoring refers to systems that continuously detect interference affecting GNSS services in a specific location or region.
Especially in aviation, the goal isn't just to observe anomalies after the fact but to establish uninterrupted situational awareness that supports immediate operational response and long-term mitigation planning.
GNSS RFI monitoring is the only infrastructure-level, short-term solution that provides real-time visibility into GNSS interference events as they unfold, across a defined airspace or region.
It's also important to understand what GNSS RFI monitoring is not:
- It is not the same as onboard mitigation, such as multi-constellation or multi-frequency receivers, advanced antennas that resist jamming, or cryptographic signal authentication (e.g., Galileo OS-NMA). These are important — but they're aircraft equipment-specific and will take years or decades to become widely adopted in civil aviation.
- It is not interference hunting. While interference hunting tools (like mobile direction-finding equipment or measurement flights) can help localize an interferer, they require manual deployment and only work after a problem has been reported or detected by other means. They are reactive by nature — not a monitoring solution.
- It is also not GNSS performance monitoring, such as systems built for GNSS augmentation or RTK services. These are typically designed to detect signal degradation from natural causes or system faults, not malicious interference. They may not detect jamming or spoofing, and they rarely provide the real-time visibility or aviation-specific context required for effective RFI monitoring.
In the context of aviation, GNSS RFI monitoring typically focuses on two critical areas:
- Ground-based monitoring near infrastructure, such as airports or CNS systems that rely on GNSS, particularly for time synchronization.
- Airspace monitoring, especially in regions where aircraft may be exposed to interference, such as near conflict zones, border areas, or high-risk air corridors.
These two domains, ground and airspace, require different monitoring strategies, but both are essential to maintaining safe, resilient aviation operations in an increasingly interference-prone GNSS environment.
Why Confusion Exists — and Why We're Writing This
As GNSS interference becomes more widespread — especially in regions with active conflict zones or criminal activity — more organizations are deploying monitoring solutions. Unfortunately, the diversity of technologies and system configurations has led to confusion about what's possible, what's necessary, and what each type of system can realistically deliver.
For example:
- Some systems only detect jamming, not spoofing.
- Some offer near real-time alerts; others analyze data in batches with hours or even days of delay.
- Some systems rely on dedicated infrastructure, others on crowdsourced data which can be unreliable with no availability and integrity guarantees.
- Others use aircraft themselves as airborne sensors via ADS-B, but their detection capabilities vary widely.
Aviation stakeholders deserve clarity — so they can make informed decisions, avoid overpromising technologies, and implement monitoring strategies that truly enhance security, safety and situational awareness.
Why Confusion Exists — and Why We're Writing This
As GNSS interference becomes more widespread — especially in regions with active conflict zones or criminal activity — more organizations are deploying monitoring solutions. Unfortunately, the diversity of technologies and system configurations has led to confusion about what's possible, what's necessary, and what each type of system can realistically deliver.
For example:
- Some systems only detect jamming, not spoofing.
- Some offer near real-time alerts; others analyze data in batches with hours or even days of delay.
- Some systems rely on dedicated infrastructure, others on crowdsourced data which can be unreliable with no availability and integrity guarantees.
- Others use aircraft themselves as airborne sensors via ADS-B, but their detection capabilities vary widely.
Aviation stakeholders deserve clarity — so they can make informed decisions, avoid overpromising technologies, and implement monitoring strategies that truly enhance security, safety and situational awareness.
Why Confusion Exists — and Why We're Writing This
As GNSS interference becomes more widespread — especially in regions with active conflict zones or criminal activity — more organizations are deploying monitoring solutions. Unfortunately, the diversity of technologies and system configurations has led to confusion about what's possible, what's necessary, and what each type of system can realistically deliver.
For example:
- Some systems only detect jamming, not spoofing.
- Some offer near real-time alerts; others analyze data in batches with hours or even days of delay.
- Some systems rely on dedicated infrastructure, others on crowdsourced data which can be unreliable with no availability and integrity guarantees.
- Others use aircraft themselves as airborne sensors via ADS-B, but their detection capabilities vary widely.
Aviation stakeholders deserve clarity — so they can make informed decisions, avoid overpromising technologies, and implement monitoring strategies that truly enhance security, safety and situational awareness.
What’s Next?
Now that you have some background, in the next two parts we'll explore:
- Part 2: System Designs & Trade-Offs
A deep dive into different GNSS RFI monitoring approaches, from ground-based sensors to spaceborne detection, and their respective strengths and limitations.
- Part 3: Practical Recommendations
Guidance on how to choose the right system setup based on your risk profile, region, and operational needs — whether you're running a national ANSP, a local airport, or a multinational aviation organization.
Stay tuned — and let's build a shared understanding of what GNSS RFI monitoring can (and can't) do today.
What’s Next?
Now that you have some background, in the next two parts we'll explore:
- Part 2: System Designs & Trade-Offs
A deep dive into different GNSS RFI monitoring approaches, from ground-based sensors to spaceborne detection, and their respective strengths and limitations.
- Part 3: Practical Recommendations
Guidance on how to choose the right system setup based on your risk profile, region, and operational needs — whether you're running a national ANSP, a local airport, or a multinational aviation organization.
Stay tuned — and let's build a shared understanding of what GNSS RFI monitoring can (and can't) do today.
What’s Next?
Now that you have some background, in the next two parts we'll explore:
- Part 2: System Designs & Trade-Offs
A deep dive into different GNSS RFI monitoring approaches, from ground-based sensors to spaceborne detection, and their respective strengths and limitations.
- Part 3: Practical Recommendations
Guidance on how to choose the right system setup based on your risk profile, region, and operational needs — whether you're running a national ANSP, a local airport, or a multinational aviation organization.
Stay tuned — and let's build a shared understanding of what GNSS RFI monitoring can (and can't) do today.
