am I correct in assuming a Garmin CIQ bug when datafields are detecting imaginary elevation gain on indoor bike rides?

I am curious to hear developers thoughts on why several datafields are repeated experiencing elevation gain on indoor bike rides (training cycle)

I assume it is because the barometer in the Fenix is improperly passing small changes in pressure as elevation changes?

Note that the FIT file itself turns off all elevation detection/recordings for such a ride, it knows that is not possible

But when the temperature or fan speed changes there appear to be tiny pressure bursts at times that the CIQ API passes as elevation?

(it's not just DozenCycle, other datafields that attempt to guesstimate power are also fooled by the fake elevation changes)

Please take a look at my bug report to Garmin here:

https://forums.garmin.com/beta-program/fenix-6-series/bug-reports/i/public-beta-26-xx/fenix6-should-not-process-barometer-pressure-change-as-impossible-elevation-gain-loss-on-indoor-bike-ride

and here's a graphed example but this happens daily, I've decoded the FIT file and the Fenix itself records absolutely no elevation at all

https://i.imgur.com/oAWQjrA.png

DaveBrillhart over 1 year ago

Weird. The CIQ API doesn't pass elevation, it reads the native device data. So possibly the FIT write logic is smart enough to null out the native device data, but CIQ gets the raw data. Are you sure you disable GPS for your indoor activity profile. I do, and my EDGE 1030 is flatlined ZERO elevation. It has a barometer too. Barometric pressure isn't going to see an impulse due to a fan spinning faster. And atmospheric drift is very slow. So my guess is your GPS sensor is on, and you're getting GPS signal noise? Even if the FIT file doesn't show the data. That would probably be a device firmware bug, not a CIQ bug. The device shouldn't pass this junk data to CIQ.

jim_m_58 over 1 year ago in reply to DaveBrillhart

With a baro altimeter, that's going to see a change in air pressure as a change in elevation - that's how floors get counted for example.

I've seen altitude vary based on hot or cold air blowing out of a vent and sitting near that air vent.

rinserepeat over 1 year ago in reply to DaveBrillhart

Fenix disables GPS when "indoor cycling" is selected.

However barometer is always left enabled to detect when people walk up and down floors.

It's very likely barometer drift from changing temperatures and air movement.

Maybe just maybe all these CIQ datafields have their own internal calculations to convert barometer to elevation if the CIQ doesn't pass that itself.

rinserepeat over 1 year ago in reply to jim_m_58

Yup I knew about the floor count thing, especially when "move iq" or whatever they call it is enabled.

Maybe these CIQ datafields are doing their own conversion to elevation when they should not be because they don't look at the activity type (indoor vs outdoor)

Always wished Garmin natively would record barometer data to FIT records (as well as magnetic compass reading which at least on the Fenix seems to be "always on" anyway as you can add it as a screen during an activity but never recorded)

jim_m_58 over 1 year ago in reply to rinserepeat

The baro elevation/pressure is always available with CIQ. You'll see it in Sensor.Info and SensorHistory, with getElevationHistory and getPressureHistory (on devices with a a baro) Why don't you just ignore this data in your data field if you don't want it?

You can probably just look at Activity.Info.currentLocation to see if GPS is on.

Ultra over 1 year ago

Indoors doesn’t mean no elevation gain. If you are riding in a velodrome you’d gain and lose a couple of meters every 250m lap as you went up and down the banking.