Improving GPS Accuracy, Distance and Speed Readings on a Instinct Watch

When using a Garmin outdoor wearable device, following some best practices will ensure that the device will provide the most accurate information possible. Here are some of the best practices to remember to ensure that the device is ready before beginning the activity.

With a strong satellite signal, the GPS position reported by an outdoor wearable unit should be accurate to about 3 meters or 10 feet. A weaker satellite signal may decrease that positional accuracy, in turn affecting the accuracy of the distance and speed readings that will be reported by the unit. The sections below provide information about a number of factors that can affect the accuracy of the position, distance, and speed readings that appear on the device. There are steps that can be taken to prevent or minimize that loss of accuracy.

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GPS Soak and EPO

Before starting an activity allow the device to GPS soak, this means to wait for an additional two minutes after the device reads GPS ready.

Ensure EPO file is current. The EPO information is automatically updated whenever the watch syncs with Garmin Express or the Garmin Connect App.

Checking EPO Satus

1. From the watch face, press and hold the Up/Menu button
2. Select Settings
3. Select About
4. Scroll down to last page to view EPO status

Recording Method

Many of Garmin's outdoor wearable devices offer the choice between Smart Recording or Every Second Recording. This setting refers to the interval at which GPS data is recorded into an activity file.

Smart Recording records key points where the device changes direction, speed, heart rate or elevation. This recording type allows the user extended recording time given that it is recording less track points, thus taking up less memory. It is important to note that Smart Recording does not affect the performance of an activity as it pertains to the data being recorded. 

Every Second Recording records the activity information every second no matter if the device changes direction, speed, heart rate or elevation. This recording type provides a more defined track log of your activity for the most accurate position, distance, and speed information. However, overall device memory will be filled up faster using this setting.

The difference between these options can be seen in the image below. The upper track represents Smart Recording while the lower track represents Every Second Recording.

Enabling Every Second Recording

1. From the watch face, press and hold Up/Menu to access the main menu
2. Select Settings
3. Select System
4. Select Data Recording
5. Select Every Second

The unit will now record track data every second, providing the most defined and accurate data.

3D Speed and Distance

The 3D Speed and Distance features change the way compatible outdoor wearable devices read speed and distance.

• 3D Speed – Calculates speed using both the elevation change and horizontal movement over ground.
• 3D Distance – Calculates the distance traveled using both elevation change and horizontal movement over ground.

Enabling These Features

1. From the watch face, press and hold Up/Menu to access the main menu 
   
2. Select Settings
3. Select Activities & Apps
4. Select activity profile to be customized
5. Select the activity settings
6. Select 3D Speed and/or 3D Distance
7. Press GPS to Enable

Once these features are enabled the device will calculate speed and distance in the data pages using 3D speed and distance.

GLONASS

Short for Global Navigation Satellite System, GLONASS is a Russian satellite-based navigation system that works alongside GPS (Global Positioning System) to provide position information to compatible devices. With an additional 24 satellites to utilize, GLONASS compatible receivers can acquire satellites up to 20% faster than devices that rely on GPS alone.

Enabling GLONASS+GPS

1. From the watch face, press and hold Up/Menu to access the main menu
   
2. Select Settings
   
3. Select Activities & Apps
   
4. Select an activity
   
5. Select the activity settings
   
6. Select GPS
   
7. Select GPS+GLONASS
   

The unit will now utilize both GPS and GLONASS satellites for quicker signal acquisition.

Galileo

What is the Galileo Satellite Network?

On December 15th the European Commission announced that the European satellite system Galileo will start offering its initial services.  Over the next few years Galileo will increase the number of satellites from the existing 18 to the full operational capacity of 30 satellites. 

Enabling Galileo

1. From the watch face, press and hold Up/Menu to access the main menu
   
2. Select Settings
   
3. Select Activities & Apps
   
4. Select an activity
   
5. Select the activity settings
   
6. Select GPS
   
7. Select GPS+GALILEO

Environmental Factors and GPS Drift

It's important to remember that the GPS signal is not powerful enough to travel through most solid objects. When using an outdoor wearable device in an area such as a densely wooded path or in the middle of a city with tall buildings, you may experience a longer time for the device to acquire a satellite signal. Once you've acquired a satellite signal you may also see a degraded performance with your GPS track (as shown in the image below) as well as your running/walking pace. 

Also, as GPS satellite signals pass through the atmosphere and interact with other environmental factors (such as trees, hills, mountains, buildings, cars, reflective surfaces and more) they can become distorted. In the past this would often cause a loss of position altogether, but with modern GPS devices that have higher sensitivity receivers, only the weakest signal will prevent the device from locating your position. As a result, GPS drift can occur, causing the device to appear to be moving even though you are standing still.

The effect of GPS drift can be seen in the image below where the hiker stopped briefly to take a break without pausing their activity:

To minimize these factors it is best to begin the satellite acquisition period when you still have a clear view of the sky, even if you are going to start the activity where the view is more limited. And, if you are going to be stationary for a while, pause the activity during that time, or enable the auto-pause feature on the device, to help limit the amount of inaccuracy introduced by GPS drift.

Enabling Auto Pause When Stopped

1. From the watch face, press and hold Up/Menu to access the main menu
   
2. Select Settings
   
3. Select Activities & Apps
   
4. Select an activity
5. Select the activity settings
   
6. Select Auto Pause
   
7. Select When Stopped
   

The unit will now pause data recording when stopped, minimizing the impact of GPS drift.