GPSrChive Discussion Forum

JungleJim wrote: ↑Sun Mar 10, 2024 4:56 pm
I don't know how Total Ascent/Descent and Elevation are determined exactly, but what I observe is that when the Elevation field changes value (for example from 0m to 1m), the Total Ascent and Total Descent fields are also updated (plus 1m in this example). So the fact that elevation determined by the device fluctuates frequently even though the actual elevation I'm at stays the same, makes that Total Ascent and Descent values are exaggerated.

Notice that the height is an integer. The actual height may be 161.52 m, then the device displays a height of 162 m, with a minimum change in height of 161.48, the receiver will display 161 m, hence there may be variations of 0 - 1 m, similarly to the temperature display when using the Tempe™ sensor.

In statistics, the value of increases and decreases does not result from the data recorded by the device during activity.

I've noticed this issue, my local walk is mostly flat, my other Garmin device records around 50-70ft ascent and descent the 67 has been recording over 600feet on the same walk! I can be walking on the flat very slightly downhill and the ascent jumped up 35feet! This device is poor for how much it cost!

Przekątny wrote: ↑Sun Mar 10, 2024 5:24 pm In statistics, the value of increases and decreases does not result from the data recorded by the device during activity.

I don't understand what you're saying here, can you please explain?

On the first page of this thread, I described the value of ascents and descents resulting from the recorded data in the gpx file provided by the dhg user.

"The ascents calculated based on the recorded data are 432 m and not 603 m as displayed in the track properties in Base Camp, the descents are 415 m and not 587 m as displayed."

It follows that the trace statistics shows higher values than are registered in the gpx file.

Przekątny wrote: ↑Sun Mar 10, 2024 7:14 pm On the first page of this thread, I described the value of ascents and descents resulting from the recorded data in the gpx file provided by the dhg user.

"The ascents calculated based on the recorded data are 432 m and not 603 m as displayed in the track properties in Base Camp, the descents are 415 m and not 587 m as displayed."

It follows that the trace statistics shows higher values than are registered in the gpx file.

Yes that's exactly the issue at hand here and what I and others are experiencing. Ascent/descent values calculated (and displayed) by the GPSMAP while an activity is in progress differ substantially from what can be calculated afterwards based on recorded elevation values as registered in the FIT or GPX file.

I guess it's a difficult problem to solve due to the coastline paradox but I think Garmin can do better!

JungleJim wrote: ↑Sun Mar 10, 2024 8:06 pm I guess it's a difficult problem to solve due to the coastline paradox but I think Garmin can do better!

In other receivers it is even more fun, you can save, archive activity and get various activity parameters in every files.
The problem has not been resolved.

I haven’t tested the ascent/decent feature myself, but the rest of my 67i is pretty much working fine, this device is only now a year old. I’m sure there will still be more updates, but unfortunately all Garmin purchasers are beta testing for Garmin, and it’s always been that way.

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Out of interest is this issue with both the 67 and 67i? or just 67?

I noticed,

When I turn on my 67 after days, it shows me the altitude at which I calibrated it days ago.
The calibration altitude is set at once.
The recording control is set to start automatically.

The device seems to adopt the altitude that I set days ago when the device is switched on.

If I set the calibration altitude to off, a different altitude appears when the device is switched on if the air pressure has changed when it is switched off.

My 66 behaves differently.
It shows me an incorrect altitude when switching on the device when the air pressure has changed when it is switched off.

The calibration altitude is set at once.
The recording control is set to start automatically.

Only when I use the Stop, Delete, Start recording control does it show me the altitude that I have previously set at this location.