The German Aerospace Center, DLR, has developed an interference-resistant GNSS receiver prototype designed to keep positioning and timing available when satellite navigation signals are disrupted by jamming, spoofing or other radio-frequency interference.
Known as GALANT, the system was developed by the DLR Institute of Communications and Navigation and uses an adaptive multi-element antenna array rather than relying on a conventional single GNSS antenna. Its key capability is spatial filtering: the receiver can electronically reshape its antenna reception pattern to strengthen useful satellite signals while creating deep reception nulls in the direction of interfering transmitters.
The technology is particularly relevant to maritime navigation, where GPS, Galileo and other GNSS constellations provide positioning and timing for vessel navigation, traffic management and port operations. In these environments, even relatively localized interference can become operationally significant because GNSS signals reaching Earth are inherently weak compared with nearby terrestrial radio transmissions.
Adaptive GNSS Antenna Array
GALANT attacks interference before conventional GNSS positioning becomes the main problem.
Instead of treating every signal arriving at the antenna as equally useful, an antenna array gives the receiver spatial information. By comparing the phase and amplitude of signals received through multiple antenna elements, the processing system can estimate where signals are arriving from and dynamically alter the combined antenna pattern.
When an interferer is detected, GALANT can place a null toward that direction while preserving reception from GNSS satellites elsewhere in the sky. DLR says this approach significantly reduces the effect of both jamming and spoofing on positioning and timing availability.
This is an important distinction from purely software-based interference detection. Detecting that a GNSS signal is suspicious is useful, but a spatially adaptive receiver can also physically suppress energy arriving from the offending direction.
The concept is closely related to Controlled Reception Pattern Antenna, or CRPA, technology, which has long been associated with resilient navigation systems but is increasingly moving into civilian and critical-infrastructure applications.
Jamming and Spoofing Defense
Jamming and spoofing require different defensive strategies.
A jammer normally attempts to overpower extremely weak satellite signals with stronger RF energy. Spatial nulling can reduce that energy before it dominates the GNSS processing chain.
Spoofing is more complicated because the unwanted signal is designed to resemble a legitimate satellite transmission. An antenna array adds another layer of information that a conventional receiver does not have: direction of arrival.
Signals from genuine GNSS satellites should arrive from different locations across the sky. A terrestrial spoofing transmitter attempting to imitate several satellites may instead cause multiple apparently independent signals to arrive from the same physical direction.
GALANT can use its antenna array not only for interference suppression but also to estimate the direction from which interfering signals originate. DLR says this capability can support localization of interference sources and potentially enable more targeted countermeasures by traffic-management authorities.
DLR has been studying array-based GNSS interference detection for years. Its researchers published work on interference detection and characterization using conformal GNSS antenna arrays in maritime environments as far back as 2017, while more recent research has examined calibration methods for antenna arrays used in spatial GNSS signal processing.
GALANT Reaches TRL 4-5
Several versions of the GALANT receiver have reached Technology Readiness Level 4 to 5, according to DLR.
That places the technology beyond a purely theoretical or laboratory concept. TRL 4 generally represents validation of components or systems in a laboratory environment, while TRL 5 moves toward validation in a relevant environment.
DLR says multiple receiver versions and several internally developed antenna-array designs are available for real-world technology validation. The institute has also developed arrays with different levels of miniaturization, an important consideration if CRPA-type protection is ultimately expected to move from specialized installations into commercial vessels, autonomous platforms and other space-constrained applications.
CRPA-Guard Moves Toward Commercialization
One of the most important aspects of the GALANT program is that the research is already moving toward a commercial product.
DLR says one GALANT configuration operates similarly to a CRPA front-end that can replace a conventional GNSS antenna while continuing to work with an existing single-antenna GNSS receiver. That version is being commercialized by German PNT specialist Lange-Electronic GmbH.
Lange-Electronic is developing the technology as CRPA-Guard, a compact system combining a four-channel CRPA antenna array with an integrated RTK-capable GNSS receiver. It performs spatial, temporal and frequency-domain processing to detect and suppress jamming and spoofing signals in real time.
The company’s published CRPA-Guard specifications indicate that the system uses adaptive digital antenna-pattern shaping, beamforming and nulling and is intended to suppress as many as three simultaneous interference sources. It also includes jamming and spoofing detection, direction finding, multicorrelator analysis and threat monitoring.
The integrated receiver adds RTK positioning capability, while the protected GNSS output means the device can potentially be inserted ahead of existing navigation equipment rather than requiring replacement of the complete downstream positioning system.
Lange-Electronic has said the technology is progressing from TRL 4-5 toward TRL 6-7 through additional development and demonstrations in relevant operational environments. The company expects the first operational CRPA-Guard prototypes during 2026.
Why GALANT Matters
The most interesting part of GALANT is not simply that it detects GNSS interference. A growing number of monitoring systems can already identify abnormal RF conditions.
Its stronger proposition is that the antenna itself becomes part of the navigation security architecture.
A conventional GNSS receiver has relatively little information about where interference originates. An adaptive array introduces another dimension, allowing the system to separate signals spatially rather than depending entirely on signal strength, correlation characteristics or navigation-message consistency.
That makes the technology especially relevant as GNSS resilience moves from a specialist military concern toward commercial transportation, ports, telecommunications, autonomous systems and other infrastructure dependent on precise positioning or timing.
There is also a practical advantage to the front-end architecture being developed from GALANT. Requiring an operator to replace an entire navigation installation would make resilient PNT expensive and slow to deploy. A CRPA unit that can function as a protected replacement for a conventional antenna could provide a much more realistic upgrade path for existing GNSS infrastructure.
The remaining challenge will be proving that miniaturized adaptive arrays can deliver consistent protection in the messy RF conditions of real installations, where reflections, vessel structures, multiple interferers and changing satellite geometry complicate idealized beamforming.
That is why the transition from TRL 4-5 toward operational demonstrations matters more than another laboratory benchmark. If the technology maintains satellite tracking and RTK-class positioning under realistic interference while remaining compatible with existing receivers, it could turn CRPA from a specialized resilience technology into a practical upgrade for civilian GNSS users.
About DLR
The German Aerospace Center, or DLR, is Germany’s national research center for aeronautics, space, energy, transport, security and defense. The organization currently employs about 12,000 people representing roughly 100 nationalities.
GALANT was developed by DLR’s Institute of Communications and Navigation, which conducts research into radio transmission, navigation, positioning, autonomous systems and cybersecurity for radio systems. The institute currently has around 255 employees, including approximately 190 scientists, working across its research locations.
Its work spans five specialist departments, including Navigation, Nautical Systems, Satellite Networks, Optical Satellite Links and Communications Systems, with applications covering spaceflight, aviation, transportation, civil security and the digital economy.
Source: www.dlr.de
