With the increasing transition to semi-autonomous and fully autonomous control systems within vehicles and marine vessels, navigation systems that provide reliable and accurate position, velocity, timing and attitude data (roll, pitch, yaw/heading) have become essential.

GNSS-assisted INS is the gold standard, but increasingly under attack

An inertial navigation system (INS) utilising inputs from GNSS and inertial measurement units (IMUs) can deliver this navigation data.

GNSS though is vulnerable to interference and jamming attacks that seek to disrupt, deny or spoof the GNSS service.

Whilst the IMUs can continue providing data for navigation during such attacks, the data is only useful for a short while - without GNSS to periodically correct it, the IMU-derived position will start to drift and quickly become unreliable.

Helix_GNSS-assisted INS under jamming orange

Reinstating GNSS

By neutralising the jammers, GNSS service can be reinstated during those periods in which the vehicle/vessel would otherwise experience service denial - in essence, shrinking large zones of GNSS-denial into much smaller pockets of GNSS outage.

The IMU component of the system can then 'plug the gap' during these outages, with GNSS position fixes becoming periodically available for resetting the errors accumulating in the INS.

Helix_GNSS-assisted INS with & without protection

Improving GNSS resiliency in this way also improves signal strength and satellite availability to improve accuracy whilst traversing GNSS-contested environments.

Designing resilient GNSS technology for use in navigation though is not easy given the necessity of maintaining phase coherence in the GNSS signal for accurately computing heading and course information.

Many CRPA designs are unsuitable

A common way of improving GNSS resiliency is through controlled reception pattern antennas (CRPA) that dynamically alter their reception pattern to neutralise jammers and maximise signal strength from the GNSS satellites.

Traditional CRPA approaches though often employ digital filtering and GNSS signal regeneration techniques which distort the phase information and so precludes their use in navigation and other ultra-precise GNSS positioning applications.

Substituting the GNSS antennas in a GNSS/INS navigation system for commercial off-the-shelf CRPAs simply doesn’t work.

Helix have taken a different approach

Through optimising antenna design and innovative RF engineering, Helix have been able to simplify the spatial processing needed in their CRPxTM thereby maintaining phase coherence and GNSS signal linearity.

In doing, Helix have been able to develop a Resilient Navigation System (RNSTM) capable of combatting jamming attacks to deliver robust and accurate navigation data whilst traversing through GNSS-contested environments.

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Helix RNSTM key features

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Multi-frequency; multi-constellation GNSS

  • Dual-band (L1/E1, L2/L5/E5a+b; supports C/A, L2C, P/Y and M-code); SBAS

  • Sharp frequency selectivity tightly tunes to the GNSS bands whilst blocking adjacent band interference (including L-Band sources & Radar)

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High performance

  • High accuracy navigation data (PVT, attitude)
  • Fast TTFF in all conditions

  • Comprehensive jamming suppression (>50dB) and non-blocking by design to suppress interference and jamming irrespective of the number of sources



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Broad applicability & compatibility

  • Navigation data (NEMA 0183) and IMU raw data outputs

  • Compact and low SWaP (size, weight & power) enables usage with small uncrewed surface vehicles (USVs) and similar platforms



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Patented UK-sovereign innovation with full UK/EU/NATO supply chain provenance

Trusted by global partners.

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Delivering resilient navigation across a wide range of applications

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Unmanned aerial and surface vehicles (UxVs) are revolutionising modern warfare but crucially dependent on resilient navigation.

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resilient. accurate. navigation.

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