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GPS vs GNSS: Understanding the Difference

The distinction between GPS and GNSS leads to confusion in industries like navigation, surveying, GIS, drone mapping, agriculture, and geospatial positioning. The terms are used interchangeably, but GPS is a satellite navigation system, while GNSS refers to the technology comprising multiple global satellite navigation systems.


Grasping the difference between GPS and GNSS is essential if someone wants to choose positioning tools, measure positioning accuracy, or develop applications based on reliable geolocation data.


GPS vs GNSS
GPS vs GNSS

What is GPS?


GPS, which stands for Global Positioning System, was created and is controlled by the United States. The GPS provides navigation services globally.


GPS receivers identify their location by catching signals transmitted from several GPS satellites. The time needed for signals to travel allows them to estimate the distance to each satellite. It takes about four GPS satellites to calculate a three-dimensional position and take into account errors caused by the GPS receiver clock.


GPS is widely applied in:


  • Smartphone navigation

  • Vehicle navigation

  • Collecting GIS data

  • Mapping with the aid of drones

  • Land surveying

  • Precision farming

  • Marine navigation

  • Search and rescue

  • Tracking of goods


What Is GNSS?


GNSS means Global Navigation Satellite System, which refers to the constellation of satellites that offer worldwide positioning, timing, and navigation services.


The most important GNSS satellite systems are:


  • GPS, US

  • Galileo, EU

  • GLONASS, Russia

  • Beidou, China


Moreover, the geo-positioning systems of certain countries (e.g., the Japanese QZSS system and the Indian NavIC system) are also regarded as part of GNSS, depending on the receiver condition.


In this way, we can conclude that GPS belongs to GNSS, but GNSS cannot be regarded as GPS only.


GPS vs GNSS: Key Difference


The simplest way to understand GPS vs GNSS is to think of GPS as a single satellite constellation and GNSS as the combined satellite navigation ecosystem.

Feature

GPS

GNSS

Meaning

Global Positioning System

Global Navigation Satellite System

Scope

U.S. satellite constellation

Multiple satellite constellations

Coverage

Global

Global

Satellite sources

Primarily GPS

GPS, Galileo, GLONASS, BeiDou, and others

Position availability

Depends on visible GPS satellites

More satellites generally available

Accuracy

High

Can provide improved availability and accuracy

Applications

Navigation, GIS, surveying, drones

Precision positioning, surveying, GIS, drones, navigation


Why GNSS Can Be Better Than GPS Alone


An updated GNSS receiver is capable of tracking signals from more than one satellite system at once. The subsequently more satellites can improve satellite geometry through the use of more satellites.


More satellites available enable the following advantages:


  1. Increased Satellite Availability


Satellites’ signals may be blocked by buildings, trees, ground, and so on. The use of several systems will increase the chances of having sufficient usable satellites.


  1. Better Positioning Reliability


GNSS receivers can advantageously choose signals from different systems to find a position. This enables better performance of navigation in difficult conditions.


  1. Better Satellite Geometry


The accuracy of determined positions does not depend only on the number of satellites used but also on their spatial disposition. Better satellite disposition provides less uncertainty for navigation.


  1. Quicker Position Fixes


Thanks to the signal from more satellites, GNSS receivers can reach positions faster.


GPS vs GNSS Accuracy


Many people incorrectly believe that GNSS devices are always more accurate than GPS devices, but the truth is more complex.


Accuracy is determined by the receiver, antenna, correction services, satellite configuration, signal quality, atmospheric conditions, multipath, and positioning technique.


A basic standalone receiver will achieve accuracy measured in meters, whereas advanced surveying instruments can achieve centimeter accuracy depending on the correction data and conditions of the survey.


For example, a drone equipped with RTK or PPK GNSS will allow for the precise positioning of its cameras and reduce the amount of ground control used in mapping projects.


GPS and GNSS in Drone Mapping


GNSS technology plays a key role in mapping and photogrammetry with UAVs.


In drone mapping, the GNSS device tracks the location of the drone during image shooting, which immediately allows integrating that data in photogrammetric processing to produce:



Drones with RTK/PPK capabilities can drastically enhance georeferencing accuracy when compared to traditional GPS systems.


The technology is particularly beneficial for surveying, construction, mining, agriculture, inspection of infrastructure, and corridor mapping.


GPS, GNSS, and GIS


In GIS, positioning accuracy influences the quality of geographic data. GNSS devices can be used to collect coordinates of roads, utility infrastructure, property lines, environmental features, and other geographic entities.


With the combination of GNSS data and GIS, organizations can merge their field data with:



All this helps to connect real-world locations with map data more accurately.


GPS vs GNSS: Which Should You Use?


GPS and GNSS may not be significant terms when it comes to routine navigation. Nowadays, gadgets such as smartphones and navigation devices are equipped with a wide variety of satellites.


However, in some specific fields of expertise such as surveying, drone mapping, precision farming, and GIS data collection, the use of a GNSS receiver is recommended.


When looking for a GNSS receiver, take into account the following features:


  • Constellations supported

  • Frequency bands supported

  • RTK capabilities

  • PPK capabilities

  • Correction services

  • Antenna quality

  • Multipath designs

  • Vertical and horizontal accuracy

  • Data formats

  • Compatibility with GIS or surveying software.


The fundamental distinction between GPS and GNSS is in terms of scale. GPS is a global satellite navigation system run by the United States, while GNSS refers to a more inclusive set of satellite navigation systems consisting of GPS, Galileo, GLONASS, BeiDou, and other satellite systems.


While in common usage, GPS is the term most commonly used for the navigation process, GNSS allows for superior positioning strategies thanks to a combination of technologies such as RTK and PPK.


With the emergence of a variety of geospatial technologies such as UAVs, LiDAR, and satellite images, reliable GNSS technology is now an integral part of any geospatial workflow.


For more information or any questions regarding GPS and GNSS, please don't hesitate to contact us at


USA (HQ): (720) 702–4849

India: 98260-76466 - Pradeep Shrivastava

Canada: (519) 590 9999

Mexico: 55 5941 3755

UK & Spain: +44 12358 56710


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