Ascent (Climbing Feet) Accuracy

[jimlarkey]

Is there any software available that will smooth the elevation data that is recorded in a GPSr's tracklog?

 

I am suspicious that the ascent (climbing feet) data reported by the GPSr and other software which simply accumulates the positive differences in elevation changes is overstated, due to scatter in data acquisition.

 

I recently completed a hike which reported 3160 climbing feet, and I computed 1800 by simply taking the differences between max & mins on ascent profile. Admittedly there are some minor ups and downs that I overlooked by using the max and mins, but I also ovelooked the scatter in elevation data acquisition, which I think significantly overstates the ascent.

 

For example, I have a Garmin 60Csx which has a barometric altimeter which probably improves the reported ascent by reducing the satellite scatter due to multipath, limited view of horizons, and poor constellation orientation. I recorded 40 minutes of standstill data (after letting the elevation settle for an hour or so), and recorded 262 feet of ascent.....standing still!!! Note the scatter that is 100% of the climbing feet reported.

 

 

Are there any elevation smoothing proggies, that can post process a track log?

 

Cheers,

Jim

Edited November 29, 2008 by jimlarkey

[+fourbeer]

Is there any software available that will smooth the elevation data that is recorded in a GPSr's tracklog?

 

I am suspicious that the ascent (climbing feet) data reported by the GPSr and other software which simply accumulates the positive differences in elevation changes is overstated, due to scatter in data acquisition.

 

I recently completed a hike which reported 3160 climbing feet, and I computed 1800 by simply taking the differences between max & mins on ascent profile. Admittedly there are some minor ups and downs that I overlooked by using the max and mins, but I also ovelooked the scatter in elevation data acquisition, which I think significantly overstates the ascent.

 

For example, I have a Garmin 60Csx which has a barometric altimeter which probably improves the reported ascent by reducing the satellite scatter due to multipath, limited view of horizons, and poor constellation orientation. I recorded 40 minutes of standstill data (after letting the elevation settle for an hour or so), and recorded 262 feet of ascent.....standing still!!! Note the scatter that is 100% of the climbing feet reported.

 

 

Are there any elevation smoothing proggies, that can post process a track log?

 

Cheers,

Jim

 

SportTracks will do this. You can also "correct" the elevation by applying the topo data to the route.

 

SportTracks will then calculate the ascent based on the topo elevation data instead.

 

http://www.zonefivesoftware.com/SportTracks/

[+RRLover]

I recorded 40 minutes of standstill data (after letting the elevation settle for an hour or so), and recorded 262 feet of ascent.....standing still!!! Note the scatter that is 100% of the climbing feet reported.

 

Cheers,

Jim

 

Crack the seal on the battery compartment while letting it settle in. Observe the alt. reading at rest and give your GPSR a couple of good squeezes and see what happens, then try it again w/the seal disturbed. Don't forget to gently and slowly tighten 'er down before embarking into the wet.

 

Norm

[jimlarkey]

Thanks fourbeers for your suggestion, but:

 

Appears that SportTracks will not export the post-processed (smoothed) gpx track.......only the original imported pre-processed track will be exported.

 

I subscribe to other hike sharing sites, so I'd like to be able to get the post-processed gpx file out of the app.

 

Any thoughts, anyone?

 

Cheers,

Jim

[Grasscatcher]

Post the original gpx file and let me play with it in ExpertGPS and TOPO!