The Sky's (Not) the Limit: GNSS in Aviation

It has become close to impossible to get through our day-to-day lives without satnavs helping us to get around. Across the globe, billions of people benefit from Global Navigation Satellite System (GNSS) applications. From communications to transport, GNSS provides global coverage, transmitting data about position and time from space.

So, it is no surprise that the GNSS industry is growing and becoming more diverse – both on the upstream side of the industry (for example, space infrastructure like satellites and signal providers) to the downstream side of things (products and services relying on positioning and navigation inputs).

When the European Global Navigation Satellite Agency (GSA) launched its last report on GNSS, European companies accounted for 25.8% of the global GNSS downstream market, “being particularly strong in the development of value-added applications”. The added-value services using GNSS were “set to skyrocket between 2015 and 2020 to reach 20% annually.”

How is aviation following the trend?

The aviation sector is no exception and has also witnessed an increase in GNSS adoption. GSA states that adoption is now still under 80% but, by 2025, the organisation forecasts that GNSS market penetration should be close to 90%, with the United States leading the way.

In its 2017 report, GSA points out some of the reasons for the increasing GNSS adoption in the aviation sector. Here are five of them:

Regulators Supporting Performance-Based Navigation (PBN)

Three years ago, the European Union’s Aviation Safety Agency recommended the extended implementation of Performance-Based Navigation (PBN). GSA also supports this view and, as PBN operations are GNSS-based, its use should grow significantly.

Rationalising Ground Infrastructure

GNSS-enabled navigation, like PBN, supports existing ground-based navigation infrastructures. However, there is a catch that the GSA describes as “an air/ground synchronisation challenge that needs the full support of both airspace users and air navigation service providers. This is another contributor to the short-term pressures on retrofit sales and the growing trend towards universal GNSS equipage within aviation.”

GNSS-Enabled Navigation

Last year, there were about 45 million flights worldwide. That’s a record number. The increase in air traffic is changing how we use airspace. It becomes crucial that aircraft fly the most economical and efficient route between point A and B, spending less time in the air. GNSS can support the concept of Free Route Airspace (FRA) for more efficient flights. This means pilots would be able to freely plan a route between two defined points, an entry and an exit, without having to refer to air traffic control services. However, those flights should remain subject to overall air traffic control.

A Solution for Drones

Drones have become a safety issue for the aviation sector and cases of these objects flying into restricted air space are increasingly common. GSA suggested high-integrity geofencing could be a solution. However, as drones are too small for ground-based radars, GNSS may be the solution.

How GNSS Supports Rotorcraft Operations

As GNSS allows high-integrity positioning, it can help with low-level operations which normally take place in challenging environments. GSA believes that the “deployment of low-level RNAV (Area Navigation) routings and the use of simultaneous, non-interfering arrivals allow rotorcraft to benefit from arrival profiles better suited to their flight characteristics whilst keeping the required separations.”

We can already see the increasing adoption of GNSS in aviation from business and commercial operators who are already using GNSS receivers integrated into their avionics. One of the biggest challenges faced by GNSS manufacturers is the need to adhere to stringent requirements from regulatory bodies.

Critical Software's GNSS Testing Framework

To help our clients with the seamless adoption of GNSS, we have developed a GNSS testing framework to verify and validate the common requirements of GNSS software. This proven framework complies with the most common GNSS software designs and can be extended to support specific receivers. The framework reduces both the time taken and the risks of certifying GNSS receiver software, as well as the costs by up to 30%.