GPS Accuracy Issues

I believe you must "Share to everyone" your activity for others to see it.

I've started using GPS - GLONASS, and so far it works very well for me. Enabling the GPS activity as soon as possible so the watch has the best chance to lock onto as many sats as possible before the activity starts can also help.

Sorry...now the activity is public!

I did a run yesterday: https://connect.garmin.com/modern/activity/3670428196

And...is not so bad after GPS updates - is a little bit off to the green path seen in the maps - which goes beneath some trees.

Here's a running with FR935 on the same path with trees:

https://connect.garmin.com/modern/activity/3607403433

FR935 seems less off.

I will do a run with GPS - GLONASS settings to see what will be as well.

I’ve recently been using GPS + GLONASS and now will try GPS + GALILEO because of what I see on an app I have installed on my phone.

The round satellites are GPS, triangle is GLONASS and the pentagon is GALILEO in the image below.

This is for my location and I’m hoping where #31 is would give me a tad better triangulation.

I will be on the trails tomorrow using GALILEO instead of GLONASS, probably doing a repeat hike from last weekend and see how it turns out and have something I can compare.

Nice! what is the name of the application? :)

It's an android app from Chartcross Limited called GPS Test. 

I did my run using GPS + GALILEO two days ago and had multiple times of signal loss. I switched back to GPS + GLONASS and did most of what I ran Saturday this morning without any signal loss. 

I'll be staying with GPS + GLONASS for now.

Had my Instinct replaced because I thought i had a bad device. Unfortunately the replacement has the exact same error with distance measurement. I run a 9,9 km trail since years and every other device (my old forerunner 305, iphone with komoot  measures 9,9 km   Only my Instinct  ALWAYS measures 8,7 km. Exactly the same error as the replaced watch.  So I think there is a poblem with the software. Mine has 4.0.0 installed 

willijayme said:

I run a 9,9 km trail since years and every other device (my old forerunner 305, iphone with komoot  measures 9,9 km   Only my Instinct  ALWAYS measures 8,7 km. Exactly the same error as the replaced watch.

I notice about the same under-measurement error with my Instinct on trail runs (mostly with heavy tree cover).  I will say that it is very consistent - about 10-12% less than the known distance (5.5 miles) every time, regardless of GPS mode.  The strange thing is that the GPS track looks better than I see on some devices (AW, iPhone, Edge,...), but it always comes up short.  Perhaps some of the other devices I've used make better use of their accelerometer in sketchy gps areas.  On open air runs with my Instinct, the GPS track and distance looks much better. 

And on bike rides, even with tree coverage, my Instinct's distance measurement is very good. 

I've noticed mine varies which is expected based on the position of satellites in the sky and nearby environment interfering, but overall I don't think you'll find much better with a device this small. I think the Instinct starting to bump up against a technological barrier between what is comfortable to wear vs what allows fine accuracy. and I'm sure a cost barrier of any existing tech that could make it more accurate at that size would be very high end equipment.

I primarily mountain bike, and that is pretty much the worst case scenario for trying to record a track with GPS. You are usually moving quickly in a place with heavy sky cover and on some trails turning back and forth which means lots of opportunities to obviously see where the drift crosses over itself. Trail running is not much better, you are moving slower which helps but you still have your antenna swinging back and forth on your arm which is bad.

For cycling, I use the ANT+ speed sensor. It counts wheel revolutions and is much more accurate for getting a distance record. The difference between the sensor and GPS will be significant, and Connect will default to the wheel sensor.

For running, I'm not sure what you can do. Does a foot pod count steps and calculate distance based on stride and steps?