Mayflower Communications Company, a Massachusetts-based leader in advanced anti-jam system solutions for military and commercial markets, has been granted two U.S. patents — US 11,262,457 and US 12,235,365 — that significantly advance its GNSS anti-jam capabilities.
The patents expand Mayflower’s proprietary technology into signals of opportunity (SoOP), enabling interference suppression across both Iridium and GNSS frequency bands.
GPS remains a cornerstone of positioning, navigation and timing (PNT) for both military and commercial platforms. However, its vulnerability to intentional and unintentional jamming and spoofing has underscored the need for more resilient PNT solutions. Signals of opportunity — non-navigational RF signals not originally intended for PNT — can serve as valuable backups when GPS signals are degraded or denied. But like GPS, these signals are also susceptible to interference and require protection to be viable contributors to a resilient PNT framework.
Mayflower’s newly patented technology provides simultaneous protection of GPS and Iridium satellite signals within a compact, low size, weight and power (SWaP) footprint — critical for modern platforms operating in GPS-contested environments.
“The issuance of these seminal patents by the U.S. Patent and Trademark Office affirms Mayflower’s continued leadership in resilient PNT technologies for both military and commercial markets,” said Triveni Upadhyay, president of Mayflower. “Our innovative approach to filtering interference across multiple satellite communication systems — including Iridium — demonstrates our ability to meet the growing demand for GPS-alternative solutions. Leveraging signals of opportunity without significantly increasing SWaP is a key milestone in delivering more robust, operationally viable PNT systems. We’re excited to bring this technology to our partners across sectors.”
Artists rendering of the B-21 raider, which is being produced by Northrup Grumman for the U.S. Air Force to operate in tomorrow’s high-end threat environment. (Image: U.S. Air Force)
With assured positioning, navigation and timing (APNT) and low-Earth orbit PNT (LEO PNT) coming on strong, what does the future hold for military and commercial systems dependent on the current configuration of GPS? Should military and commercial platforms be modified to include APNT, for now, with an eye to adding LEO PNT in the future? Should they integrate these two systems, or rely on one or the other as standalone systems?
Government and industry agree that interference with GPS and all GNSS is an increasing threat as jamming and spoofing technologies evolve. This has prompted government support for APNT to bolster GPS. A Feb. 12, 2020, Executive Order required a comprehensive update to national policy on PNT services by the federal government, and by owners and operators of critical infrastructure to strengthen the resilience of critical infrastructure.
Research, development and production have improved the performance — positioning, timing and (desired) accuracy — of GNSS PNT and the ability to operate in RF-challenged environments. APNT gives the U.S. military a reliable way to further enable GPS, or to act as an alternative to it, by utilizing other sensors, such as inertial navigation systems, differential GPS, visual sensors, lidar, radar, radios and star trackers that complement GPS.
The near-term expansion of internet service to include commercial broadband LEO satellites also provides potential for robust PNT, using their waveforms as signals of opportunity (SOOP). GPS and other GNSS have an infrastructure to maintain very precise time throughout their constellations, as well as satellites with specially designed transmitters, clocks, and a waveform dedicated to the PNT function. By contrast, SOOPs are in space for another purpose and not optimized for PNT. Therefore, the challenge is to exploit features of the SOOP waveforms, designing innovative techniques to determine the range to each satellite and to provide users with reliable PNT. The approach for LEO PNT may have applications to ground troops and for aerial, munition, missile and commercial applications requiring higher levels of PNT security and integrity.
GPS receivers for future military platform designs may use a software defined radio (SDR) approach and be capable of incorporating LEO PNT signals. This technology, although designed to work standalone, can be used to complement existing navigation sensors that are typically used in navigation systems, including APNT. Expansion to the usage of multiple constellations will serve to optimize performance and resiliency in an RF-challenged environment. However, LEO satellites’ closer proximity to Earth and their signal structures allow for higher signal powers, thus are more robust against jamming. With all these separate systems or fusion by SDR, how does the receiver ensure the integrity of the signal or its accuracy? An SDR qualification test would involve an unlimited number of scenarios.
One hallmark of the GPS program is that it facilitates a thorough systems engineering effort by managing in a single location interface control documents (ICDs) for alternative systems being developed by different program offices all over the country. This makes both the integration of the systems and the development of the receivers extremely difficult and complex.
“The new SPD-7 [Space Policy Directive 7, the United States Space-based Positioning, Navigation and Timing Policy, dated Jan. 15, 2021] focusing on interoperability and APNT is a seminal document to address a realized threat and a way forward,” said Bernie Gruber, a former head of the GPS Directorate (now the Military Communications and PNT Directorate). “To that end, the combination of SDRs and data fusion potentially offer a clear advantage to utilize signal and sensor diversity, thus improving the robustness of critical PNT information.”
Sponsored by: Loctronix Corporation Broadcast Date: Thursday, May 22, 2014
Host: Dr. Michael B. Mathews, CEO and Founder, Loctronix Corporation
Speakers: Franck Boynton, Vice President and CTO, NavtechGPS; Peter F. MacDoran, Chief Scientist, Loctronix Corporation; Michael O. Davies, Senior Engineer, Loctronix Corporation Summary: The need for robust, highly-reliable, navigation information in GNSS-denied environments is fast becoming a critical issue for unmanned aerial vehicles (UAV) / unmanned aircraft systems (UAS) in both commercial and military applications. Total reliance on GNSS can lead to disastrous consequences when signals are interfered with or obstructed. Low-cost, non-SAASM, GPS sensors are particularly vulnerable to jamming and interference. Attendees will learn how robust, cost-effective Hybrid GNSS Technologies (HGT) offer unique capabilities for UAV navigation in environments where traditional GPS receivers may fail. Combining signals of opportunity (SoOps), inertial sensing, and multi-frequency GNSS using Spectral Compression Positioning, assures continuous navigation by detecting typical GNSS interference and mitigating their effects through alternative navigation means. Download a PDF of the webinar slides
