From GPS to Galileo: How GNSS Is Redefining Safety at Sea

Today, GNSS has become an essential component of our daily lives and global navigation operations. From ships and aircraft to cars and industrial systems, millions around the world rely on GNSS satellites for precise positioning, optimal timing, and reliable data. As a result, users face significant challenges such as weak signals, reflections, or limited understanding of how the system works, which can impact performance and efficiency.

For this reason, it is essential to fully understand GNSS—from the satellites and constellations that comprise them to the ground networks and stations that monitor the signals. Failure to fully utilize GNSS can undoubtedly lead to positioning errors and affect global navigation operations.

What is Global Navigation Satellite System (GNSS)?

Truth be told, GNSS is an umbrella term for all global navigation satellite systems that provide accurate location and time information at any point on the Earth's surface. This system relies on a constellation of satellites orbiting the Earth in specific paths to ensure global coverage.

Of course, each GNSS satellite sends signals containing orbiting, timing, and status data, which are received by GNSS receivers, which calculate the precise location using trilateration techniques.

In this context, global GNSS systems include:

• GPS – United States.
• GLONASS – Russia.
• Galileo – European Union.
• BeiDou – China

There are also specific regional systems—such as IRNSS in India and QZSS in Japan, that provide accurate navigation services in specific regions.

It’s good to note, most modern GNSS systems, including Galileo and GLONASS, can receive signals from more than one constellation, ensuring efficient Earth positioning, reliable stations support, and real-time global navigation capabilities.

How Does GNSS Work?

Of course, these systems operate through three main components:

Space Segment: 

This includes satellites orbiting at an altitude of approximately 20,000 km above Earth. Each satellite sends signals containing information about its positioning, timing, orbiting, and status.

Control Segment: 

A network of ground-based monitoring stations that analyze signals, correct errors, and transmit them to satellites in the constellation to ensure data accuracy and global coverage.

User Segment: 

The devices or receivers used on ships, aircraft, or smartphones to determine Earth positioning and timing. This also includes supporting operations such as hatch cover inspections and the use of monitoring stations to ensure the accuracy and management of marine equipment.

Using these three components, GNSS provides accurate information anywhere on the Earth's surface, whether at sea or on land, ensuring reliable coverage in all regions.

What is the Difference Between GNSS and GPS?

Without doubt, many people confuse GNSS with GPS, but there is a fundamental difference:

GNSS: An umbrella term for all global satellite navigation systems that provide accurate positioning and timing data. It includes systems such as GPS, GLONASS, Galileo, and BeiDou.

GPS: An American-based system, one of the most popular GNSS systems, comprises approximately 31 satellites and provides near-global coverage.

Key Differences:

GNSS encompasses all systems to provide the best global accuracy, while GPS is only one part of this framework.

The current trend is to use multi-GNSS receivers to improve Earth positioning accuracy and coverage, especially in challenging environments where Galileo, GLONASS, monitoring stations, and other systems enhance overall performance.

Practical training is essential to avoid errors, which is why maritime safety training courses in Humborg remain an ideal choice for developing skills and familiarizing yourself with modern GNSS technologies.

What are the Factors that Impact GNSS Accuracy?

Despite the accuracy of GNSS satellites orbiting the Earth, there are factors that can reduce it:

• Signal obstruction by buildings, bridges, or trees.
• Underground or indoor use.
• Reflections from metal or concrete surfaces.
• Severe solar storms.
• Satellite maintenance.

Still yet, even with high GNSS accuracy, errors can occur due to inaccurate maps or missing data, which is why understanding the system and using equipment that supports GLONASS and other constellations to maintain positioning consistency is so important.

Eventually,

GNSS systems reflect significant advances in global navigation and satellite positioning, contributing to improved safety of both maritime and terrestrial operations, strengthening Earth-wide navigation reliability.  

Whether you're based in London, Dubai, Athens, Rotterdam, Hamburg, or Istanbul, LMA Training delivers internationally accredited maritime safety training adapted to local and global requirements, supported regionally with flexible training methods.

If you're in charge of a maritime fleet or work in the navigation industry, investing in understanding and effectively using GNSS is a direct investment in global safety, positioning accuracy, and performance.