Instinct Solar - 18.10 Public Release Candidate

trux said:

Barometric altimeters do now work when submerged

Well, OK, if you want to be pedantic, they do work even when submerged, but they do not work correctly, since the pressure they read is no more the atmospheric pressure. Much higher hydrostatic pressure overrides the reading. Already 1 cm of water column over the watch would result in pressure change equivalent to the negative elevation change of almost hundred meters.

3 satellites triangulation to get the altitude at any given time, then it's simple math to track gain/lost ??

Anyway, the update is in the right direction. I had the new Instinct solar watch showing 8 miles with over 60000 ft elevation gain (vs ~2500 ft actual)...many many times before the update. I was told the v15.x software/math was doing 1/1000 instead 1/10000...so was off by at least 10x.

Mike said:

3 satellites triangulation to get the altitude at any given time, then it's simple math to track gain/lost ??

GPS does not work when the watch is submerged either  Besides that, you can use the GPS elevation instead of the barometric values, on the activity screen if you want, too. Just note that the vertical accuracy of GPS is almost an order of magnitude worse than the horizontal accuracy, so forget about using it at surfing for detecting waves.

However, if you mean (unlike the original question asking whether the barometric altimeter works while surfing), the elevation profile at common outdoor activities, then you have even a better option than the inaccurate GPS altitude - turn on the Elevation Correction in Garmin Connect Web, and the elevation profile will be adjusted using the topographic data for given track. Much more accurate than the GPS alone.

Mike said:

3 satellites triangulation to get the altitude at any given time, then it's simple math to track gain/lost ??

https://myrickchow.medium.com/as-simple-as-possible-why-does-gps-need-at-least-4-satellite-signals-5bff178fedc0 

https://www.microblife.in/why-are-4-satellites-needed-for-gps-2/ 

Has anyone tried disabling the barometer and using just altitude to see if that helps?  I went for a flat run the other day with "auto" for altitude and it reported 8,000 vertical feet of elevation. A week ago I did a run that I knew had 7100 vertical feet and it reported over 15,000. It doesn't seem to be a simple math issue with the algorithm but maybe a conflict between the two sensors. Elevation charts look like a sawtooth and max and min elevation is also way off. I'll try this beta (currently using 17.5) but based on some of the comments below it looks like there are still issues. It's a new watch so hoping it's a SW issue and not HW. thank you. 

1211243 said:

It doesn't seem to be a simple math issue with the algorithm but maybe a conflict between the two sensors.

There is only one sensor - the pressure sensor. The elevation is calculated from the change of the air pressure, so if there are simultaneously also atmospheric pressure changes, they are either dismissed (altimeter mode), or oppositely all the pressure changes (both fractions) are contributed to the atmospheric change (barometer mode). The auto mode does nothing else, than trying to guess which of the mode should be used. At outdoor GPS activities it is then (mostly, if not always) the altimeter mode that is used. 

Yes I know. GPS and barometer. 

My question still stands. Has anyone tried disabling the barometer as a quick fix until garmin figures out the problem. 

I share the data recorded during a bike ride with Edge 1030 and Instinct solar with beta V18.10. For me this version is already better, with the V17.50 the total ascent values were always much higher, sometimes tripled.

1211243 said:

My question still stands. Has anyone tried disabling the barometer as a quick fix until garmin figures out the problem.

You mean using exclusively the "altimeter mode"? That's what happens when you start an outdoor activity, and use the default "auto mode" anyway - it locks into the altimeter mode automatically, and that's exactly why it will almost never report the same elevation at the start and at the end of an activity, when coming back to the starting point. There will be almost always difference of up to several tens of meters, because the atmospheric pressure changed in the meantime, and it was not accounted for, because the watch was in the altimeter mode.