Keeping up with jamming, spoofing threats

Hexagon | NovAtel’s GAJT-710ML installed on a U.S. Army vehicle. Photo: U.S. Army Futures Command

We asked Dean Kemp, Ph.D., director of Marketing, Aerospace and Defense for Hexagon’s Autonomy & Positioning division, a few questions.

How do jamming and spoofing threats change?

Jamming and spoofing methods change as new interference-causing technologies become available. As such, it’s vital for us to continuously evaluate potential sources of threats and provide the highest possible level of resiliency to interference in our solutions.

Have new threats emerged in the past six weeks in connection with Russia’s invasion of Ukraine?

Evidence is emerging that electronic-warfare systems capable of high-power jamming and spoofing across wide areas are being used within Ukraine. Fortunately, there have been no known impacts on allied forces. However, knowing that the technology is in place and in use highlights the importance of assured positioning, navigation and timing (APNT) and our contribution to building resiliency in allied forces’ equipment against the potentially destabilizing effects of jamming and spoofing.

How do you define APNT?

We use APNT to describe measurements that are always accurate, available and reliable. Our anti-jamming, anti-spoofing and other resilience-building capabilities provide trusted and available PNT information at the level of accuracy requested.

When did you introduce GPS Anti-Jam Technology (GAJT)? How do you define it?

GAJT was introduced in 2011 and is our leading APNT solution. GAJT units are utilized worldwide across land, sea and air, with rapid deployment supported by commercial off-the-shelf solutions and short lead times. GAJT provides jamming protection of satellite-based navigation and precise timing receivers from intentional jamming and unintentional interference whatever your application. Product variants provide features to best support anti-jamming capabilities for the warfighter, national infrastructure, low-SWaP platforms and other mission-critical applications.

What are the key differences between the GAJT-710ML, the GAJT-710MS and the GAJT-410MS?

The GAJT-710 is designed for land vehicles (ML variant) and marine vessel platforms (MS variant) with up to six simultaneous nulls to protect against jamming signals and interference. The next generation of GAJT-710 includes jammer direction-finding and a silent mode to reduce its thermal signature. The GAJT-410 maintains the high levels of interference-rejection performance in the 710 but in a lower size, weight and power (SWaP) design, with three simultaneous nulls, for both land and marine variants. It also utilizes a single RF cable to provide clean power, data and protected GPS signal. The GAJT-410 enables APNT while also reducing the need for platform modifications or armor penetration.

The GAJT-AE extends jamming and interference protection to unmanned and autonomous applications. Using an external CRPA antenna, the GAJT-AE offers flexibility of integration into space-constrained platforms.

Is the GAJT-AE-N Anti-Jam Antenna receiver-agnostic?

We designed our GAJT product line to be receiver-agnostic and compatible with legacy and modern GNSS receivers. This flexibility results in GAJT being ideal for civil and military applications, including SAASM and M-code systems.

How does your GNSS Resilience and Integrity Technology (GRIT, launched in 2020 November) relate to your GAJT antennas?

GRIT is a firmware suite for our OEM7 receivers that expands their situational awareness and interference mitigation tools. GRIT includes our Interference Toolkit (ITK) along with spoofing detection to identify when your GNSS signal may be under threat. It also empowers the user to develop interference location algorithms through time-tagged snapshots of data samples to characterize the RF environment around your operations. GRIT, alongside GAJT, forms the foundation of our APNT strategy in providing accurate and always-available PNT.

Do you have any recent contracts with the U.S. Department of Defense or the militaries of other NATO countries to supply GAJT antennas?

Our GAJT product portfolio has been sold in large quantities to military and civil organizations for many years, successfully proving itself in the field. In 2020, we achieved a milestone of more than several thousand units shipped worldwide, making it one of Hexagon | NovAtel’s more successful years.