Saab is developing a navigation solution so that its Gripen C/D and E/F fighters can operate in environments where the use of GPS is denied by the enemy. The system may be offered to aircraft s from the end of this decade.
On the modern battlefield, the development and use of GPS negation tactics and equipment is increasingly common. “The position of your own platform is really important, and over time the requirements for the accuracy of this positioning have increased more and more – now we are talking about gauges”, said Gripen test pilot Jonas Jakobsson.
“For years, the ideal solution has been Global Navigation Satellite Systems [GNSS], and most often GPS, to achieve this,” he watches the pilot. However, severe GPS blockages have been experienced during major military exercises in Scandinavia, and minor disruptions can also be caused by natural events such as solar flares.
With air forces needing the highest level of precision in navigation and targeting to ensure that no collateral damage is caused when precision-guided weapons are employed (such as GPS-guided JDAM bombs), Saab is looking to defeat these tactics of anti-access/area denial (A2/AD).
Saab's proposed solution will combine data from Ternav, its existing terrain navigation system, real-time odometry images via the camera installation and a 3D mapping surface model provided by Maxar Technologies via a sensor fusion. This will provide much greater positional accuracy than using traditional inertial measurement unit equipment, says Saab.
Jakobsson says that if the military chooses to avoid operating in areas affected by GNSS denial, then “it's a really cheap A2/AD gun” for an opponent. And while anti-lockdown technologies can help, that may not be the case in highly contested areas, he notes.
In 2018, Saab and Maxar conducted test flights with the Gripen using a pod-hosted camera to assess the potential of such a system. In 2020, this work was expanded to conduct real-time processing with the Gripen E/F demonstrator.
“It was a success,” says Tobias Jansson, product manager for Gripen. Additional test flights could take place in about a year, he says. Saab's terrain navigation expertise dates back to the 1980s and the Viggen fighter. Its technology was later improved for the Gripen program but was not adopted by the Swedish Air Force, which opted to rely on the GPS system.
Jansson revealed that the capacity was offered to Finland as part of Saab's offer to the HX Programme. 64 Gripen Es and two GlobalEye surveillance aircraft were offered. “We think that this capacity is important for a country that is very close to an opponent that has this capacity [of interference]”, he says.
Referring to the expansion of the A2/AD threat, Jakobsson notes: “If you are a country that does not have its own national GNSS system, then you are dependent on someone else. You don't have the autonomy to say 'we can always count on 100% access'”.
Jakobsson notes that the system would also be valuable in ing operations using dispersed bases – a tactic that is employed by both Finland and Sweden to reduce vulnerability to attacks against air bases. In this way, air forces employ their fighters from ordinary highways. Recently, Finland itself held a training like this, where its F/A-18 Hornet landed and took off from a road during the day and night.
Gripen already has the unique ability to perform a so-called “nav” landing using GPS. “Now, instead of GPS, we will use this functionality”, he says. "To take it a step further, autolanding is something we've discussed and have studies on." This approach and landing function “off-grid, automatic IMC [instrument flight conditions] and landing would be very useful in a war scenario”, he affirms
“We think this is one of the pillars you will have to face denied GNSS operations”says Jansson. The operational capability of the entire system, including 3D mapping, could be achieved “within three to five years”, he suggests. A solution based on odometry would also be "Super easy" present for Gripen C/D through software updates, says Jansson. “There is great interest from existing [Gripen] customers and we are continuing that discussion,” he adds.
Modular technology also has potential application for other types of platforms, such as GlobalEye and unmanned aerial vehicles, as well as air-launched weapons, Saab believes.
With Flightglobal
