Welcome back to our channel! When we talk about navigation, we use terms like GPS, GNSS, GLONASS, dual-frequency.
It can all be so confusing – especially if you’re thinking about buying or just learning how to use a navigation device.
That’s why I’m here today – to put your mind at ease and help make these terms a little less intimidating.
So let’s go through some of the basics of GPS Technology.
Starting with the obvious question, what is GPS?
Well GPS, or Global Positioning System, is a satellite-based navigation system made up of at least twenty-four satellites.
GPS works in any weather conditions, twenty-four hours a day, with no subscription fees or setup charges.
As the GPS satellites circle the earth twice a day, each satellite transmits a unique signal that allows GPS devices to compute the precise location of the satellite.
GPS receivers use this information to calculate a user’s exact location.
Essentially, the GPS receiver measures the distance to each satellite based on the amount of time it takes to receive a transmitted signal.
With distance measurements from multiple satellites, the receiver can determine a user’s position and display it electronically.
To calculate your 2-D position, meaning your latitude and longitude, the GPS receiver must be locked on to at least three satellites.
And when locked on to four or more satellites, the receiver can calculate your 3-D position which adds altitude.
Garmin devices support a variety of Global Navigation Satellite Systems, or GNSS for short.
There are many satellite constellations that make up the GNS System.
Some examples include GPS – the U.S. constellation that we just talked about, GLONASS – the Russian constellation, and Galileo – the European constellation.
While some devices support a single satellite system, others support multi-GNSS.
This is when two GNS systems work together for position, speed and time.
For example, in the Fenix 6 settings menu, you can select GPS only, GPS plus GLONASS, or GPS plus Galileo.
Utilising multiple GNS systems will help track your location in more challenging environments than when using GPS alone.
Ultimately, the more satellites you can track, the more reliable the signal will be.
And with newer Garmin products that have multi-GNSS support, you could be tracking up to twenty satellites.
I know it’s a lot to take in but stay with me. Some products will even go a step further and have multi-band or dual-frequency GNSS support.
By utilising both the L1 and L5 frequencies, along with multi-constellation support, dual-frequency units allow for more consistent tracklogs and improved positioning in challenging environments,
including around tall buildings, in urban canyons, and heavy tree cover.
And dual-frequency units will increase your accuracy to within plus or minus three metres under ideal conditions.
Until recently, dual-frequency units were really expensive, costing thousands of dollars, and mainly used in high-end applications such as surveying.
But with evolving changes in technology, dual-frequency units are making their way into the consumer market at affordable prices – such as our GPSMAP 66sr.
So what does all of this mean for you as a user?
Well first and foremost, I hope it’s helped you understand GPS technology a little better.
But also if you’re thinking about purchasing a GPS unit for your next adventure, I hope it gives you some things to consider when choosing the right GPS for you.
Thanks for taking the time to learn about GPS Technology Basics.
For now, that’s all I‘ve got.
I'm Matt from Garmin hoping that wherever your adventure takes you, we’ve helped you beat yesterday!