"GPS frequency disruptions render navigational systems ineffective or unreliable and can even lead to the destruction or capture of GPS-based technologies like vehicles, ships, and drones."
Precision GPS is an integral part of our daily lives, securing everything from high-risk military operations to efficient transport and logistics. However, with so much reliance on GPS technologies, certain industries and applications are vulnerable to malicious attacks from GPS jamming and spoofing.
GPS interference to critical signal relays can cause severe problems, so it’s more important than ever that entities protect themselves with innovative, state-of-the-art technologies and GPS anti-jamming techniques that can safeguard operations and personnel.
How do they do it?
We give an in-depth overview of just that and more below.
What Is GPS Anti-Jamming?
Anti-jamming in GPS refers simply to a set of technologies and techniques that are designed to disrupt GPS jamming signals and protect critical systems that rely on GPS.
GPS jamming occurs when an RF signal, often broadcasted intentionally, disrupts and overpowers a GPS signal being relayed from space to an earth-bound GPS receiver. GPS frequency disruptions render navigational systems ineffective or unreliable and can even lead to the destruction or capture of GPS-based technologies like vehicles, ships, and drones.
How Anti-Jamming Technology Counters GPS Jamming
To counteract GPS jamming, one must enhance the signal resilience of targeted GPS receivers. This can be done in a variety of ways, but the most effective GPS anti-jamming techniques often use adaptive GPS anti-jamming antennas that can detect and prevent jamming signals from reaching the receiver.
These antennas use advanced signal processing techniques that filter out RF noise (improve the Signal-to-Interference-Noise Ratio - SINR), as well as spatial diversity methods that employ two or more GPS antennas to ensure GPS signal capture and enhance signal clarity.
The above techniques are essential in ensuring a GPS receiver can continuously capture GPS signals and are particularly useful in applications like military operations, maritime navigation, supply chain and logistics, and emergency services.
The Value of GPS Anti-Jamming
Regardless of the application, GPS anti-jamming technology is highly valuable, offering services that do everything from enabling autonomous vehicle operation to saving lives in the most dire of situations.
GPS Anti-Jamming Applications
Military Operations
When it comes to military and defense, GPS anti-jamming is crucial to maintain security and ensure successful operations. Military forces rely heavily on GPS, be it for communication between personnel, scouting & observation in complex environments, or manned & unmanned vehicle operations, making GPS jamming a severe threat that must be considered at all times.
Since GPS signals can be jammed or spoofed relatively easily, anti-jamming GPS techniques are crucial for safety and success.
Anti-jamming technologies can help ensure successful execution for all sorts of missions and applications in a variety of environments, enhancing the safety of missions and personnel and providing a strategic advantage against adversaries.
Maritime Operations
The maritime industry is arguably one of the most threatened by GPS interference, and most entities operating in the maritime space stand to benefit greatly from GPS anti-jamming technologies.
Vessels use GPS for navigation, cargo tracking, supply chain efficiency, and collision avoidance and are even used in emergency search and rescue scenarios such as a man overboard or ship collision. GPS jamming can severely disrupt a ship’s navigation, so vessels and crews are put at high risk when it occurs - especially for prolonged periods or during inclement weather.
Anti-jamming GPS receivers help ensure safe vessel journeys and protect against shipping congestion at ports or in open water. They can also help ensure a secure lifeline for emergency crews in more extreme scenarios.
Emergency and Disaster Response
GPS anti-jamming is one of the most critical pieces of technology in the event of an emergency or natural disaster.
Hurricanes, tornados, wildfires, and more can create hectic environments that are hard to navigate safely and efficiently, so having a birds-eye-view of the landscape can drive situational awareness and increase the odds of safe operations.
First responders like police, firefighters, medical teams, and food aid organizations rely on GPS to navigate a disaster area with timeliness and precision. Without it, it could lead to anything from failed rescues to mismanaged supply drops.
For example, the ongoing conflict in Gaza is inclusive of heavy amounts of electronic warfare, so when disaster relief teams need to enter a recently affected zone, it’s possible that GPS signals are not available. In this case, teams could arm themselves and their tools with GPS anti-jamming technologies that can help them reach the targeted disaster area and provide the relief needed.
Economic Impacts of GPS Jamming
While the safety and operational impacts of GPS jamming are sometimes easy to identify, the economic impacts of GPS jamming are often overlooked.
GPS jamming creates significant financial risk across a variety of industries - disrupting supply chains, causing delays and errors in operations, and undermining communications in scenarios that can lead to extreme financial woes.
One commonly overlooked use for GPS systems is in agriculture, and the economic loss in this sector can be detrimental. Precision agriculture requires to-the-second timing when operating GPS-enabled machinery, and when those GPS signals are disrupted, it can cause negative implications on crop health, yields, and disease.
When crop production is impacted significantly, especially in high-output or remote locations, it can even reduce food security - potentially putting communities and economies in danger.
In commercial aviation, GPS is imperative to keeping flights on schedule and maintaining a safe and efficient airspace. When GPS signals in airports or the airspace are compromised, flights end up delayed, supply chains are disrupted, and many are left delayed in reaching their destinations. The fallout of these instances can and do cause severe economic loss, which can extend beyond the airlines and even reach into consumers' pockets.
While the above-described situations are anything but exhaustive, they provide real-world examples of how the loss of GPS signals can have major economic impacts on people and communities.
GPS Anti-Jamming Methods
There are three primary methods in which anti-jamming technologies build resilience against jamming signals.
Nulling
When GPS interference is detected, a nulling system generates a “null” in the direction of the GPS jammer being used, which eliminates unwanted RF noise. When more than one jammer is being used to try and overpower a legitimate GPS signal, nulls will be generated in the direction of each jammer.
Beamforming
In beamforming, a “beam,” or RF pattern, is directed towards a known GPS satellite, ultimately making interference less likely, as a jamming signal would need to be coming from the exact direction of the known satellite.
Excision
Excision eliminates any type of narrowband interference that exceeds set thresholds as defined by statistics. Any signal surpassing these thresholds is eliminated, leaving the remaining signals to be transformed for “nulling” - described above.
Types of GPS Anti-Jamming Technologies
Entities use numerous types of GPS anti-jamming technologies to secure their equipment and operations and build resilience to jamming and interference. While different technologies are designed for different applications, they exist to support all types of land, air, and sea-based operations.
Anti-Jam Antennas
A GPS anti-jamming antenna is pretty much what it sounds like - an alternate type of GPS antenna that helps maintain secure GPS connections.
Traditional GPS antennas are often omnidirectional, meaning they can pick up GPS signals from almost any direction. Anti-jamming antennas, on the other hand, focus on a specific direction of known GPS satellites. Focusing signals received from known GPS satellites can reduce the overpowering signals transmitted by GPS jammers.
Another type of GPS anti-jamming antenna is a Controlled Reception Pattern Antenna (CRPA), which uses beams controlled by a signal processing unit that runs advanced algorithms to detect potential jamming signal patterns and adjust the antenna to prevent a jamming signal from overpowering the target signal.
Anti-jamming antennas like the GAJT-710MS made by Veripos are made specifically for vessels operating in some of the more remote offshore locations of the world. This specific anti-jamming antenna combines an antenna array and “null-forming electronics” into a marine-hardened enclosure that can be installed on nearly any marine vessel, construction site, or offshore drilling rig.
GPS Domes
While military-grade anti-jammers are effective for larger vehicles and machinery, they are often unusable for smaller, more compact technologies like drones and UAVs. In response to this fact, GPS domes were created.
GPS jamming has emerged as one of the most prominent threats to commercial and defense drones. Without GPS signals, these small craft are vulnerable to GPS jamming attacks, often leading to craft interception or crashes.
Infinidome is one company developing anti-jamming technologies that can be retrofitted onto small craft like drones, allowing GPS receivers to safely and efficiently secure valid GPS signals while eliminating the opportunity for RF interference.
These anti-jamming domes come in a few different configurations and can defend against L1, L2, and L5 frequencies - depending on the application. They are compatible with nearly any off-the-shelf GPS receivers, offering protection from up to three simultaneous jamming attacks for each band. They are lightweight, compact, and use little power, making them some of the most suitable market solutions for small to midsize drones and UAVs.
Space-Based GPS Jamming Detection
Another solution to defend against GPS jamming involves detecting the source of GPS jamming signals from space using state-of-the-art satellite technology offered by companies like Spire Global.
Spire’s approach to GPS jamming detection involves its growing constellation of small satellites orbiting the globe in LEO. These satellites are equipped with GNSS reflectometry (GNSS-R) payloads that study GNSS signals (GPS signals) that are reflected and scattered by the Earth’s surface. The L-band antennas capture raw recordings of these data, which can be used to detect and geolocate the source of GPS jammers.
While this approach is more reactive than it is defensive, it can be a highly useful tool that can help eliminate threats from a variety of environments and mitigate future risks by taking action at the source.
For those with ongoing GPS anti-jamming needs, Spire even offers custom-built satellite constellations that can be tasked by location, mission, and more to help reduce the risk to operations or safeguard everything from military missions to supply chain logistics.
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