New combined system blocks jamming in GPS-denied environment
- By Katherine Owens
- Jul 28, 2017
The Inertial Navigation System (INS) by Honeywell Aerospace navigates without emitting a single GPS signal. The ADA GPS anti-jamming system by Israel Aerospace Industries (IAI) stops jamming signals in their tracks. Together, these two technologies strive to ensure the survival of GPS navigation in the age of electronic warfare.
“Facing today’s threats to GPS, the ability to combine advanced anti-jamming capabilities as part of the Embedded GPS INS systems is a must,” said Boaz Levi, Executive Vice President of the IAI Missile and Space Group.
The IAI and Honeywell Aerospace memorandum of understanding, which announced the project that will combine the INS technology with the ADA anti-jamming capabilities, was released this week. The ADA technology will become a system component of the embedded INS, according to the IAI press statement.
The ADA system is able to shield a platform using GPS from multiple jamming signal sources and can be installed on a wide variety of platforms from drones, to surface vehicles, to munitions platforms, reported IAI.
According to industry developers, anti-jamming technologies work by using a sophisticated antenna to receive incoming GPS frequencies in the typical L1 and L2 frequency bands and then convert them into high-speed, digital frequencies. Then, gain-pattern shaping algorithms turn the digital frequencies into a single, high-power output signal. When directed at the sources of jamming, that signal translates into “nulls” or blind spots that the jamming signals cannot penetrate. In other words, it channels the GPS signals to electronically jam the jammer.
The ADA system can be installed as part of a new jamming immune GPS receiver or a “plug and play” feature that can be connected through radio frequency cables to any existing GPS receiver. Typical hardware includes a central processing unit, RF cables connecting to the GPS receiver, and additional cables connecting to the antenna. According to IAI statements, it is about seven cm by eight cm and weighs a little more than five pounds.
When combined with the INS, the system will remain compatible with the currently employed military GPS frequency and the next-generation m-code frequency.
The m-code frequency is part of the military’s initiative to maintain GPS signal security. It is a military-specific signal that uses split spectrum modulation, meaning that most of the signal power is relayed near the edges of the designated bandwidths using a 10.23 MHz square wave subcarrier. Security of m-code signal ensured by next-generation cryptography and new keying architecture, according to a joint military-industry report lead by the Air Force GPS Joint Program Office.
The GPS INS developed by Honeywell uses computers, accelerometers (motion sensors), and gyroscopes (rotation sensors) to calculate velocity, position, altitude, the azimuth of the platform, and coordinated universal time. According to the American Institute of Aeronautics, the system computes this information without any external signal links.
Platforms installed with the new integrated INS/ADA system will be able to navigate in GPS-denied environments and then reinforce the navigational information, and at the same time blocking the jamming signals as the ADA system transforms incoming GPS signals.
The exact time when the new combined system will become available is not yet public information, however, when available, “the joint product can be deployed as a turn-key solution or as an upgrade to IAI and Honeywell’s existing customer base,” said Levi.
Katherine Owens is a freelance reporter for Defense Systems