GNSS vs GPS Technology: Key Differences Explained

GNSS and GPS work hand in hand to improve accuracy and efficiency.

Today’s navigation system has become an essential part of everyone’s life. These technologies are widely used in different industries to achieve more accurate readings.

Modern navigation technology not only helps in measuring distances and angles ideally, but also makes exclusive use of these measurements in various industries.

The mapping and surveying industries are among the first to use GPS technology, which is more accurate, faster, and requires less human resources.

Ground control and drones are used frequently by earthwork companies to guide worksites toward greater efficiency and productivity.

Although satellite navigation was originally used for military applications, the use cases of these technologies have become bigger in the present times. It includes private and public sectors across multiple market segments, such as construction, science, and more.

Most of you might be familiar with GPS. It can you significant time while exploring an unfamiliar place. However, GNSS is a less-used term.

In this article, I’ll familiarize you with GNSS and explore the differences between GPS and GNSS. In the end, we will discuss which is more flexible, reliable, and accurate for your use case.

Here we go!

What Is GNSS?

GNSS stands for Global Navigation Satellite System, in which different countries operate many satellites. This is done to provide signals from space and transmit timing and positioning data to the GNSS receivers located on Earth. The receivers further use these data to determine your precise location.

The multiple satellites orbiting the Earth are known as constellations; hence, GNSS also refers to the constellation of satellites. It can be used in transportation, space stations, rail, mass transit, road, maritime, aviation, etc.

Navigation, positioning, and timing are essential in land surveying, emergency response, mining, precision agriculture, finance, law enforcement, scientific research, telecommunications, and more. The performance of GNSS can be improved using regional satellite-based augmentation systems, such as European Geostationary Navigation Overlay Service (EGNOS).

Examples of GNSS: USA’s NAVSTAR GPS, Europe’s Galileo, China’s BeiDou Navigation Satellite System, and Russia’s Global’naya Navigatsionnaya Sputnikovaya Sistema (GLONASS).

EGNOS helps improve the reliability and accuracy of GPS information by providing data about the integrity of the signals and correcting the signal measurement errors. Well, the actual performance is assessed through four primary criteria:

Accuracy: It’s the difference between the measured speed, time, or position and real speed, time, or position.
Continuity: It signifies whether a system functions without any interruption.
Integrity: The capability of a system to offer a threshold of confidence in the positioning data and alarm is integrity in this context.
Availability: The percentage of time that a signal needs to fulfill accuracy, continuity, and integrity criteria is “availability” in this context.

GNSS technology needs at least four satellites to compute your location through complicated trilateration calculations. Nowadays, three segments define satellites in space.

These are considered vital parts of GNSS technology:

Space segment: The space segment defines the constellations orbiting between 20,000 to 37,000 km above the Earth’s surface.
Control segment: The control segment is the network of data uploading stations, monitoring stations, and master control stations located around the globe.
User segment: The user segment describes the equipment that receives signals from the satellite and outputs a position based on the orbital location of the satellites and time.

What Is GPS?

Global Positioning System (GPS) is a radio navigation system used on air, land, and sea to determine the accurate location, velocity, time, and more irrespective of the weather conditions.

GPS was first developed in 1978 as a prototype by the US Department of Defense. It became completely operational in 1993 with an entire constellation of 24 satellites.

GPS is owned by the United States government and is operated by the US Space Force. With GPS, not only military officials, but also commercial or civil users worldwide are benefiting. Although the US created and controls the GPS, it is accessible to everyone with a GPS receiver.

GPS is a type of GNSS technology that provides time and geolocation data to the GPS receiver. It doesn’t require any user to transmit the data but operates flexibly on any device with a good internet connection.

In technology, advancing new concepts is a primary priority for everyone. So, the technological demands on the existing system lead to modernizing the GPS. It implements the next-generation operational control system and GPS block IIIA satellites.

GPS comprises three parts – satellites, receivers, and ground stations. Let’s go through the functionalities of each:

Satellites: It acts like stars in the constellations and sends out signals.
Ground stations: It uses the radar to ensure the satellites are in the position we think they are.
Receiver: It is a device you can find in your phone, car, etc., that invariably seeks signals from satellites. Furthermore, it determines how far you are from the location you want to know about.

GNSS vs. GPS: Working

How does GNSS work?

GNSS varies in design and age, but the operation is the same. The satellite transmits two waves in L-band i.e., L1 and L2. These carrier waves transmit data from the satellite to the Earth.

GNSS receivers consist of two parts – one is an antenna, and another one is a processing unit. The working principle of both the units is straightforward. The antenna receives signals from the satellites while the processing unit senses the signals. It needs at least four satellites to collect accurate information to determine the position.

GNSS satellites orbit the Earth every 11 hours, 58 minutes, and 2 seconds. Every satellite is capable of transmitting coded signals that contain a stable time stamp and orbit details. The signals contain information that a receiver needs to compute the satellites’ locations and adjust accordingly for accurate positioning.

The receiver calculates the time difference between the signal reception time and the broadcast to compute the precise distance. It gives results in the form of height, longitude, and latitude.

How does GPS Work?

GPS works through a trilateration technique that collects signals from satellites to provide output location information to the user. Satellites orbiting Earth send signals to be read and interpreted by the GPS readable device situated near or on the Earth’s surface.

The GPS device must read signals from at least four satellites for an accurate location. Each satellite circles the Earth twice daily and sends a unique signal, time, and orbital parameters.

Since a GPS device gives information on the distance from the satellite, a single satellite will not be capable of providing an accurate location.

Like GNSS constellations, GPS also includes three segments: space, control, and user.

Space segment: The space segment consists of 30+ satellites in orbit operated by the US Space Force. These satellites can broadcast radio signals to monitor and control stations on Earth.
Control segment: The GPS control segment includes backup, several monitor stations, dedicated ground antennas, and master control worldwide. This ensures GPS satellites are working well and orbiting in the right position.
User segment: The user segment refers to everyone who relies on GPS satellites to measure position, navigation, and time.

GNSS vs GPS: Advantages and Limitations

Advantages of GNSS

Now, we know the term GNSS, which covers three or more satellites from different countries to provide you with correct and accurate information. Here are some of the benefits of GNSS:

All global navigation systems are available every moment. If one is not working due to atmospheric conditions, another will help in the same way. Hence, GNSS provides more availability and access to the signals to the receivers.
You will get accurate timing data which is further used to develop high precision IoT network.
Since it is a constellation of satellites, it improves the navigating solution, enhancing TTFF, which means Time to First Fix.
It saves money and time by delivering location accuracy to your device.
You will get uninterrupted connectivity in every location, such as vast forests, caves, densely populated places, etc.
GNSS receivers automatically remove the failed satellite from the navigation list to provide you with the best solution.

Limitations of GNSS

Following are some limitations of GNSS:

Augmented systems are needed every time you use GNSS systems to support precision approaches.
Vertical accuracy is more than 10 meters.
Augmented systems are deployed to meet availability, accuracy, continuity, and integrity requirements.
It affects aircraft operators, pilots, air traffic services, regulatory personnel, etc.
The safety of navigation depends on the accuracy of the databases.

Advantages of GPS

It is straightforward to use
Low cost
100% coverage of Earth
Due to its accuracy, you can save fuel
You can use GPS technology to find nearby hotels, gas stations, shops, etc.
It is easy to integrate into your devices
It provides you with the solid tracking system

Limitations of GPS

The GPS chip drains all your battery in your device.
It doesn’t penetrate solid walls. This means users can’t use the technology indoors or underwater.
The accuracy depends on the signal quality of the satellite.
The position varies when the number of satellites is limited.
During geomagnetic storms or other atmospheric conditions, you will not be able to access the location.
The land survey equipment needs a clear sky view to receive signals.
Sometimes, the inaccuracy may show you another invalid way or location.

GNSS vs. GPS: Applications

Applications of GNSS

The GNSS technology was first developed in the 20th century to help military personnel. With time, the technology finds its way to many applications:

During manufacturing, automobiles are equipped with GNSS that display moving maps, location, direction, speed, nearby restaurants, and more.
Air navigation systems use a moving map display. It is also connected to the autopilot for route navigation.
Ships and boats use GNSS to locate oceans, seas, and lakes. It is also used in boats for self-steering gear.
Heavy equipment used in construction, precision agriculture, mining, etc., uses GNSS technology to guide machines.
Cyclists use GNSS in touring and racing.
Climbers, ordinary pedestrians, and hikers use this technology to know their position.
GNSS technology is also available for the visually impaired.
Spacecraft use this technology as a navigation tool.

Applications of GPS

GPS has many applications across the globe. Let’s find out some of them.

The aviation industry uses GPS to provide the passengers and pilots with the aircraft’s real-time position.
Marine industries provide accurate navigation applications to boat captains.
Farmers use GPS receivers on their farming equipment.
Surveying
Military
Financial services
Telecommunications
Heavy vehicle guidance
Social activities
Locating positions
Nearby places
Seeking treasure
Solo travels

And so on.

GNSS vs GPS: Differences

We all know about GPS as the go-to tool that helps find any location, restaurant, address, and more. You can even share your present or live location with others. Through GPS, we can access locations, but during any interference in the signal, you will not be able to access location or information.

GNSS is a term with similar operations as GPS but with more flexible and reliable access to the locations even during interference. It includes GPS, Baidu, Galileo, GLONASS, and other constellation systems. That’s why it is referred to as the International Multi-Constellation Satellite System. You can say GNSS uses multiple GPS satellites from various countries to navigate the accurate location.

Let’s dig deeper into the main differences between the technologies based on some aspects.

Criteria	GNSS	GPS
Orbital Altitude	It combines the orbital altitude of various satellites, such as 19,100 km for GLONASS and 20,200 for GPS.	GPS satellites fly way above the Earth’s surface at an altitude of 20,200 km or 10,900 nautical miles with a period of 12 hours
Precision	It gives more precise information. The result you will get with precision at the centimeter or millimeter level.	It provides less precise information as it can fluctuate due to atmospheric conditions, signal blockage, etc. It records its precision at 4.9m to 16ft.
Origin Country	GNSS systems include GPS from the US, GLONASS from Russia, Galileo from Europe, and BeiDou from China	It is a type of GNSS system which was developed in the US.
Satellites	It has 31 satellites from GPS, 24 from GLONASS, 26 from Galileo, and 48 from BeiDou	It has 21 satellites in orbit
Period	The period of various navigation systems are: GLONASS: 11 hours and 16 minutes Galileo: 14 hours and 5 minutes BeiDou: 12 hours and 38 minutes NAVIC: 23 hours and 56 minutes	It flies in circular orbits with a period of 12 hours or twice a day
Status	The status of each navigation system differs, such as GLONASS is operational, BeiDou has 22 operations satellites and more.	The status of the GPS is operational
Signal	The power level of GNSS is 125 dBm and is differed according to the satellites from various countries.	It is constant to 125 dBm signal strength.

GNSS provides more accurate data as it combines the coming information from various satellites of various countries. On the other hand, GPS is the specific data provider controlled and maintained by the US government.

Conclusion

GPS is a type of GNSS, which was the first Global Navigation Satellite System. In general, GPS is often used to describe a satellite navigation system. Both are the same in terms of their operations but differ in their working styles.

GNSS and GPS are used in multiple fields where you need precise and continuous available time and position information, such as transportation, marine navigation, mobile communications, agriculture, athletics, and many more.