A Spanish industrial consortium finalises the fine-tuning of a family of encrypted receivers for the PRS service of the European navigation constellation

GMV secures Galileo's governmental and military navigation systems

PHOTO/JPons - The director of the Navigation Business Unit of the Galileo and PRS user segment in GMV, Manuel Toledo, with a group of his engineers in front of the prototype of the "Presence" receiver at the FEINDEF show in Madrid in May 2023.

Engineers from the Spanish technology company GMV are in the final stages of completing a sophisticated family of electronic equipment. Its function is the correct reception of the shielded and secured signals of the European navigation and positioning system Galileo that are routed to recipients in the public interest.

  1. The solution: Galileo PRS 
  2. On the final path 

Positioning signals from the Galileo satellite constellation can reach an accuracy of "20 centimetres horizontally and 40 centimetres vertically", which is "much higher" than its US equivalent GPS, says the European Union, which owns the space network. So GMV's technicians are trying to ensure that the Galileo signals arrive protected and encrypted to their official recipients and cannot be interfered with, degraded or manipulated. 

GMV and a couple of Spanish high-tech companies - Indra and Tecnobit - have been working together for more than four years on a new range of Galileo receivers to be used exclusively with governmental authorisation by national and international institutions, agencies and organisations linked to security, defence and critical infrastructure management. 

The European Union and the European Space Agency (ESA), the Brussels-based technology partner that has made the development, deployment and operation of Galileo possible, claim that the network already serves "more than 3 billion users worldwide". But what they do not realise is that the open, free and open access Galileo signals received by consumer smartphones have serious weaknesses.

Even the Commercial and Critical Applications modes, which incorporate a receiver with access keys to use a large number of paid applications, have weaknesses. But neither are encrypted, making it possible for hackers, organised criminals and terrorist groups to cause damage that would be difficult to repair. 

PHOTO/ESA -The PRS service broadcasts its signals on two frequencies, which are equipped with authentication codes to prevent interference and spoofing and, if necessary, to detect and locate them.

The solution: Galileo PRS 

Such threats are not acceptable when governments and international organisations use Galileo to maintain public services and national defence is at stake. Much less acceptable when military units on land, at sea or in the air are engaged in warfare.

In the cases outlined above, a "reliable, robust and fully secure" navigation, positioning and timing service is essential, which, from the point of view of a GMV engineer, is what can make the difference between life and death for soldiers engaged in combat. 

PHOTO/DLR - The ground segment control centre in Oberpfaffenhofen (Germany) is responsible for monitoring the performance of Galileo satellites and signals.

But the problem is solved. The founding fathers who designed the architecture and technical foundations of the European constellation have also conceived the so-called Public Regulated Service or PRS. 

Galileo PRS incorporates a set of authentication codes that detect and avoid interference and prevent spoofing. In parallel, they offer the highest conditions of security, accuracy and availability, as the satellites broadcast their PRS signals on two frequencies. 

What is the status of Galileo's PRS mode and is it already fully operational? European Union officials are preparing for the PRS service to enter service in the course of 2024. The 28 Galileo space platforms in orbit are already equipped with PRS transmitters and the ground network responsible for key distribution is already deployed.  

PHOTO/ESA-Anneke Le Floch - The European Space Agency (ESA), the EU's technology partner in the constellation, has made possible the development, deployment and operation of Galileo, which already has more than 3 billion users. 

On the final path 

In Spain, the Directorate General for Armaments and Material of the Ministry of Defence is leading the national implementation of Galileo PRS, the key link being a "made in Spain" receiver called "Presence". The suppliers are the consortium formed by GMV, which is responsible for signal processing and navigation in the receiver, with the contribution of Indra, which has developed the electronic antenna with shaped beams that mitigate possible interferences, and Tecnobit, which provides the PRS security module with its encryption systems. 

PHOTO/ESA-G. Porter - At ESA's European Space Research and Technology Centre in the Netherlands, a senior Galileo programme manager shows European Commissioner Thierry Breton the ins and outs of a Galileo satellite. 

The "Presence" demonstrators have already been tested in different environmental situations and in very extreme conditions with the Armada on the future F-110 frigates and on the P-77 Infanta Cristina patrol boat. They have also been tested by the Military Emergency Unit (UME) and the Air and Space Army. They have even been tested in several Antarctic campaigns, both at the Spanish base "Gabriel de Castilla", in its vicinity and on board the oceanographic research vessel Hespérides.

The conclusions drawn from the Antarctic are that "Galileo with PRS is more reliable than GPS with a military module, because it orients itself and covers signal reception in polar latitudes much better". In short, GMV says it has already completed the development of the receiver models for the future F-110 frigates being built by Navantia for the Navy, which are essentially the same as those that could be fitted as standard on the new "Dragon" tactical vehicles and installed in land-based centres. 

PHOTO/ESA-CNES-Arianespace –  The last two Galileo satellites, numbers 27 and 28, were launched into space in December 2021. The next two are scheduled to be launched in April and two more in July this year. 

Manuel Toledo, head of the Navigation Business Unit of GMV's Galileo and PRS user segment, responsible for the development of "Presence", points out that his team is now immersed in developing the equipment for aircraft and drone versions. Is size the main reason for the difference between the two? Well, not only. 

PHOTO/ESA-P. Carril - Positioned 23 222 kilometres from Earth, the constellation currently consists of 28 spacecraft, of which 23 are operational, four are in reserve and one remains out of service. 

It is obvious that for aircraft the receiver has to be as small as possible. But another factor is just as important, if not more so. "It is not the same to obtain a highly accurate positioning at 120 kilometres per hour, the speed at which a tactical vehicle can travel, as it is to perform high-dynamic manoeuvres in flight at Mach 2 in a fighter jet, i.e. twice the speed of sound. GMV's team is now focused on resolving the above questions.