G-Metrix Elevation and Grade issues

I am using an overlay that displays Elevation and Grade on my videos. The elevation figures being reported (coming from data captured on my VIRB Elite camera) don't seem to have any relation to reality. In many cases the elevation reported goes to serious negative numbers - I don't live in Death Valley. The Grade measurement, with the 'fake' elevation measurements is also not in touch with reality.

When starting measurement of speed - the figures shown on the overlay go from zero to three digits and back to zero ????

0 schinder over 7 years ago

The VIRB Elite is useless for altitude even though it has a barometric altimeter because there's no way to calibrate it and whatever self-calibration it's doing doesn't work. Occasionally you'll get lucky, but most of the time it's simply off. The worst offset that mine ever gave was that it showed 3000 ft at the start of a ride (I live at 1200 ft, and the highest point in the area is at 2400). Your best bet is to use the track from some other device in VIRB Edit.

0 mmi16 over 7 years ago

The VIRB Elite is useless for altitude even though it has a barometric altimeter because there's no way to calibrate it and whatever self-calibration it's doing doesn't work. Occasionally you'll get lucky, but most of the time it's simply off. The worst offset that mine ever gave was that it showed 3000 ft at the start of a ride (I live at 1200 ft, and the highest point in the area is at 2400). Your best bet is to use the track from some other device in VIRB Edit.

I have a Garmin 1300 GPS unit with the altitude option set - I wouldn't say it is totally accurate but it stays within a believable range until you get around sea level.

0 schinder over 7 years ago

If you mean a Nuvi 1300, it's usually possible to get the track off of a Nuvi, but it's not nearly as easy as one of the sports devices (Edge, Forerunner, Fenix, etc.) You'll probably need to plug it into a computer and rummage through the filesystem to find the track (almost certainly a gpx file). But the Nuvi won't have a barometric altimeter, so if it records altitude at all, it'll be GPS based, so it will be plenty noisy and maybe not worth using (it will stay within about 100 ft of the correct value, but it will vary within those bounds). It's straightforward to use the G-Metrix from another device rather than the data from the Elite in VIRB Edit, and now you can do it field by field so you can replace just the altitude or just the speed.

0 mmi16 over 7 years ago

If you mean a Nuvi 1300, it's usually possible to get the track off of a Nuvi, but it's not nearly as easy as one of the sports devices (Edge, Forerunner, Fenix, etc.) You'll probably need to plug it into a computer and rummage through the filesystem to find the track (almost certainly a gpx file). But the Nuvi won't have a barometric altimeter, so if it records altitude at all, it'll be GPS based, so it will be plenty noisy and maybe not worth using (it will stay within about 100 ft of the correct value, but it will vary within those bounds). It's straightforward to use the G-Metrix from another device rather than the data from the Elite in VIRB Edit, and now you can do it field by field so you can replace just the altitude or just the speed.

Not that important to me - just playing around with the bells and whistles.

It would be nice if lateral acceleration numbers were reasonably accurate - but there again it is just bell/whistle.