GPS vs. GNSS: the difference in satellite nagivation systems

Some of our development boards will be equipped with GPS or GNSS technology. What is the difference and how do they compare?

GPS (Global Positioning System) and GNSS (Global Navigation Satellite System) are related technologies used for determining the precise location and navigation of objects and individuals on or near the Earth's surface. However, there are some key differences:

1. Number of Satellites and Constellations:

   • GPS: GPS is the original and most well-known satellite navigation system. It was developed and maintained by the United States government. It relies on a constellation of around 30 satellites in medium Earth orbit (MEO).
   • GNSS: GNSS encompasses multiple satellite navigation systems from different countries and regions. This includes GPS (USA), GLONASS (Russia), Galileo (European Union), BeiDou (China), and other regional systems. GNSS combines signals from multiple satellite constellations to improve accuracy and global coverage.
     
     

2. Global Coverage:

   • GPS: GPS provides global coverage, but signal reception can be limited in certain areas due to obstructions like tall buildings or dense vegetation.
   • GNSS: GNSS offers more comprehensive global coverage because it incorporates multiple constellations. This makes GNSS more reliable in various geographical locations.
     
     

3. Independence:

   • GPS: GPS is operated and controlled by the United States Department of Defense. It was originally developed for military purposes and has been made available for civilian use.
   • GNSS: GNSS includes satellite systems from multiple countries, each with its own control and operation. This diversity can enhance the overall resilience and availability of satellite navigation services.
     
     

4. Accuracy and Precision:

   • GPS: GPS is known for its high level of accuracy, especially in the civilian mode. However, accuracy can vary depending on factors such as the quality of the receiver and the presence of signal obstructions.
   • GNSS: GNSS, by combining signals from multiple constellations, can provide even higher accuracy and precision than using GPS alone. This is particularly beneficial in challenging environments where GPS signals may be weaker or obstructed.
     
     

5. Compatibility and Interoperability:

   • GPS: GPS is a standalone system, and some devices may only support GPS. However, many modern devices are designed to be compatible with multiple satellite constellations, providing users with the benefits of GNSS.
   • GNSS: GNSS receivers are designed to work with signals from multiple satellite constellations, making them more versatile and capable of providing accurate positioning and navigation in a variety of situations.

While GPS is a specific satellite navigation system operated by the United States, GNSS is a more inclusive term that encompasses multiple satellite systems from different countries. GNSS offers the advantage of improved accuracy, global coverage, and resilience by combining signals from multiple constellations, including GPS.