具有出色抗干扰能力的GNSS接收机：挪威JammerTest的结果
在此次测试中使用了“点烟器”干扰器，这是最常见的干扰器类型之一，可以很容易地在网上购买到。它发射功率在10-15 dBm之间的信号，干扰GPS L1、L2信号。其他干扰测试包括信号强度比GNSS信号高1千万倍的高功率干扰器。
下图显示了使用“点烟器”低功率干扰器进行的移动干扰测试的结果。信噪比时间图显示，当干扰开始时，跟踪的GNSS信号的质量会下降。如上图所示，Septentrio接收机能够继续跟踪信号并输出定位，而其他接收机会在一段时间内失去定位。
Danger: Spoofed positions without a warning
This graph shows a summary of performance of various receivers during spoofing testing throughout the 5-day event. The green sections represent the percentage of correct positions or successful spoofing mitigation. Grey indicates the percentage of time the receiver reported no position during spoofing, and red shows the percentage of time the receiver displayed spoofed positions.
The Septentrio receiver showed minimal spoofed positioning, even under sophisticated spoofing attacks, and consistently detected and flagged spoofing when it occurred, demonstrating situational awareness. In contrast, three competitor receivers failed to flag spoofing in many cases, displaying erroneous positions without warning the system of potential risks.
Resilience of GNSS timing validated
The plot below shows results from a test where GNSS time was spoofed. The Septentrio receiver maintained accurate timing, while a competitor receiver was spoofed and displayed incorrect time. Applications such as telecom, power grids, and financial institutions depend on precise GNSS timing. Malicious spoofing can result in outages, with total costs reaching millions of dollars or euros. Investing in resilient GNSS technology is essential to protect mission-critical systems and the users who depend on them.
Multi-layered receiver protection pays off
During JammerTest 2024, Septentrio receivers with AIM+ technology demonstrated exceptional resilience to high-powered jammers and various types of spoofing. This performance reflects over 25 years of expertise in developing reliable GNSS positioning technology, incorporating multiple layers of protection:
- Multi-frequency technology for signal diversity, ensuring fallback during jamming or spoofing
- Cryptographic signal authentication (OSNMA) to verify genuine signals
- Anomaly detection powered by continuously updated big data from years of field observations
As seen on the news, GNSS spoofing is increasingly common due to readily available transmitter hardware and signal simulator software. Spoofing poses an even greater risk than jamming, as it can not only disrupt operations but also manipulate navigation systems, potentially resulting in planned collisions or theft. Securing your system at the receiver core is the most effective strategy to ensure resilient, reliable operation.
Learn more about AIM+ Anti-Spoofing technology or download our comprehensive GNSS Spoofing brochure. The video below is a summary of Septentrio’s results from JammerTest 2024. Feel free to share this video with those interested in resilient and reliable positioning.
Tried, tested and true
Always accurate and available Positioning, Navigation and Time or Assured PNT is key to successful industrial or critical operations in challenging environments. By regularly participating in live events such as the JammerTest, Septentrio's anti-jamming and anti-spoofing technology is continuously being tested and improved to withstand the latest interference attacks. This technology has also been confirmed to be effective by users out in the field, who are using Septentrio receivers in places of malicious interference, such as near contested borders.
Although an anti-jam antenna can play a role in hardening the system, the most effective approach to securing your system is to use a receiver with advanced anti-spoofing and anti-jamming (AJAS) protection. For spoofing this means including several layers of protection which shield the receiver from various types of attacks. Septentrio receivers come in various formats from rugged boxes to OEM boards and compact modules, like the low-weight, low-power mosaic-X5 module receiver, which is also easy to integrate and is compatible with popular autopilots like Pixhawk, ArduPilot and PX4 Autopilot. For more information about resilient GNSS receivers and technology please contact Septentrio.
AIM+ detects and mitigates GNSS jamming
The figure on the right shows that during jamming a Septentrio GNSS receiver in a car delivered accurate positioning along the whole route (orange track), while a high-end GNSS/INS competition receiver lost positioning two times (red track).
During this test a “cigarette” jammer was used, which is one of the most common types of jammers and can easily be purchased online. It emits signals with power between 10-15 dBm and jams GPS L1, L2 signals. Other jamming tests included highly powerful jammers with signals 10 million times more powerful than GNSS signals.
The plot below shows results of a mobile jamming test performed with the “cigarette” low-power jammer. The signal-to-noise time plot shows that when jamming is started the quality of the tracked GNSS signals decreases. A Septentrio receiver, shown at the top continues to track the signals and to output positioning, while a competition receiver loses positioning for a period of time.
相关手册
Tests with various anti-jam antennas showed interference reduction of about 10 dB due to the antenna. While advanced anti-jam technology like AIM+ plays a key role in positioning availability under jamming, an antenna plays a supporting role and can improve the chances of getting positioning in cases where the jamming is still slightly stronger than the ability of the receiver to mitigate it. While anti-jam antennas can be effective for wide-band “white-noise” jamming they are less effective for other types of jamming.
Comprehensive anti-spoofing requires multiple layers of protection
Hackers employ various types of spoofing to hijack positioning, navigation or time, from simple asynchronous spoofing to sophisticated synchronous types which are almost identical to real GNSS signals. For the highest degree of anti-spoofing protection and situational awareness a receiver requires several layers of protection (find out more in our GPS Spoofing brochure).
AIM+ detects, flags and mitigates GNSS spoofing
The plots below show positioning of several different receivers in a moving car during a GNSS spoofing attack.
