Swimming GPS accuracy of Suunto 5
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@vinay even a very thin layer of a few cm of water will fully block the GPS satellite frequencies. Remember: Civil GPS is using 1600MHz frequencies. These are microwaves, similar to those used ina microwave oven (2400MHz), where their only purpose is to be absorbed by water.
Plus the signal propagatino delay will be differenz under water. Since the whole GPS navigation is based on signal propagation times of a few nano seconds, this will also have an effect.
Conclusion (as said before): Forget about getting anything out of a GPS receiver if the antenna is not frequently lifted out of the water.
If you swim breast stroke, put the watch under your swimming cap or into a buoy etc. Everything else will result in random data. -
@egika said in Swimming GPS accuracy of Suunto 5:
Remember: Civil GPS is using 1600MHz frequencies. These are microwaves, similar to those used ina microwave oven (2400MHz), where their only purpose is to be absorbed by water.
Ah cool, funny way to think about it like that, that’s for sharing!
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Is the GPS accuracy setting set to best? It’s also possible to combine navigation systems.
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@activejiggy
neither of these settings improve the fact that gnss signals don’t go thru water -
@egika Fair enough. You’d expect Suunto might come up with a swim-gps pod at some point. After all they also have a digital HR sensor that’s good for swimming. Putting the watch on your head or on a floater might solve the GPS issue, but you’ll use some functionality like measuring your cadence etc. Plus of course I’d be worried to lose the watch if it isn’t secured.
So yeah, you can move the watch to another place so you win some (GPS reception) and you lose some (cadence etc). I’m personally fine with the way it is now but for someone who values better GPS reception when swimming, a separate GPS dongle may be good. Might be nice if it also works for those with a Suunto 3.
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@vinay
the track is already reasonably good if you do crawl - freestyle swimming (?)… breaststroke and gps tracking basically doesn’t work at all for me -
@freeheeler Oh yeah sorry, I don’t know all the names in English. I do crawl indeed, no breaststroke. That might be the difference between our GPS tracks (as mine was reasonably fine).
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@freeheeler True, the best setting will sample every second though. Maybe it just needs a constant fix though.
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@activejiggy
it needs filtering as shown in the pictures… as I am not a swimmer, I prefer to do surfboard paddle training but most recently with open water swimming mode instead of SUP mode as previously… see the difference:SUP mode:
ows mode (I did paddle a triangle, not the exact way back):
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@freeheeler same session or different session?
Personally I did use and always use SUP profile so that you can get stroke rate, distance per stroke, along with pace -super useful for determining when you have caught a wave. -
@jamie-bg
that was a different session, I can not record 2 records in one session with one watch
for surfing there would be surf mode but I haven’t used it much and don’t know what it records.
for SUP I’ll keep using SUP, but for just surfboard paddle training, I’m going to use open water swimming -
So i was testing this a lot last two weeks. While breast swimming style, i must put my hand few centimeters above water and wait 10-30 seconds to get gps fix every time i want to record swimmed distance. It is sometimes hard to do if there are waves but it is possible. But after some time i just stoped doing it and recorded just openwater swimming without GPS. So i have just time and stroke. I think strome rate and time is more important than GPS track. Since there are water currents distance is less accurate tu measure work done.