GPS Speed measurement - Horse galloping

[Mark97213]

I'm trying to measure my horse's galloping speed but am wondering if my older Garmin etrex color, can measure short bursts of speed, accurately? The runs would just be fairly short bursts of speed, so, is there a way to measure the highest speed obtained... or will the GPS just give me the average speed over the distance traveled?

[+Timpat]

Hmmm, interesting question here. Your eTrex should do well for this test. I think if you set the tracklog recording option to time and the shortest interval (1 sec?) you should get the best results. You can then review the tracklog in Mapsource or BaseCamp and see the speed recorded at each track point. It may show some outliers but a good representation is likely.

[Mark97213]

Ahh... hmm, I'll have to give this a shot and see how to do this. Thank you so much for the your help with this. I also purchased the new Montana 650T to use for deep in the woods trail riding as my etrex almost became worthless in such deep cover. Anyway, do you think there is any benefit in one over the other for the speed measurements?

[+Mineral2]

Ahh... hmm, I'll have to give this a shot and see how to do this. Thank you so much for the your help with this. I also purchased the new Montana 650T to use for deep in the woods trail riding as my etrex almost became worthless in such deep cover. Anyway, do you think there is any benefit in one over the other for the speed measurements?

 

The Montana is more likely to pick up a better signal/ give you more accurate positioning. Aside from that, it'll only be better if it samples more often than the eTrex, which is a possibility, but something to look into. On the other hand, your eTrex is lighter and smaller and probably easier to deal with on a horse.

[+Redwoods Mtn Biker]

Keep the Montana out, with as clear of a view of the sky as possible. And remember, there are good satellite days and bad satellites days. The satellite constellation position is constantly changing.

[+Red90]

Also note that a GPS measures speed directly and separately from position. It is not averaging distance over time.

[Mark97213]

Great advice, thank you all for the education. Yes indeed, the etrex will be much less cumbersome as it's pretty small compared to the Montana and if it comes lose at around 45mph, I'd rather it be the etrex.

[+Woodstramp]

Interesting subject. Sounds like you should be able to get what you want with the speed.

 

Once, can't recall where, I saw an image online in in one of these forums where someone had recorded a track, inserted it on a Google Earth satellite image and the track was colorized to show speed changes during the track length. I think it was a recorded track of a mountain biker. Kind of neat to look at.

[tr_s]

Problem with speed sports that involve quick changes in speed and acceleration is that a normal GPS only samples once a second. Interpolating between the sample points might not give a very consistent view of what actually happened.

 

I think Garmin has a 5 sample/second Bluetooth/USB GPS module which is much more suitable for these kinds of things.

Edited August 31, 2013 by tr_s