Forums > Windsurfing   Gps and Speed talk

Devices for GPSTC in Rules page

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Created by Cocky2 > 9 months ago, 15 Sep 2018
AUS3333
31 posts
28 Sep 2018 8:12AM
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boardsurfr said..



Cocky2 said..
You will find a link to this file in an earlier post I made in the Topic.






Sorry I had missed that, thanks for posting it again. Here's a few things I noticed looking at the track. First, a comparison of the doppler and positional speeds for the entire track:

The "33 knot" region is where the green line is. What jumps out is that there are many spots where the positional speed is much higher than the doppler speed, up to 100 knots. That's unusual - for comparison, here is a recent Canmore track where there are only small differences:




It is quite common to see spikes in the speed graph during crash/swim episodes. Here is an example from another recent Canmore file (I used the Canmores as loaners for GPS competition at our East Coast Windsurfing Festival last week):




As theGPSlooses and gains reception, the position jumps a lot, and this sometimes "goes through" to doppler speeds. Similar artifacts while swimming/crashing can be seen with Locosys andu-bloxGPS units.

During the first hour of Callan's session, there are just two speed spikes, and they both seem linked to crashes (the first one is a "maybe"). Here is the second crash:

This is a clearcut case of a crash in a jibe, and did not affect doppler speed.

Now to the "33 knot" region:





This does not seem linked to a crash (Mike was correct in this assessment). But the speeds are quite spiky before the "33 knots", with large differences between positional speed and doppler speed. This indicates that the GPS did not get a good reception. The run was after a longer break or swim. There is a 60 knot spike in the speed graph about 80 seconds earlier, probably because the upper arm was completely in the water. It's likely that the armband moved during this break/swim so the GPS was below the arm, and/or that water got into the GPS.

Overall, though, the picture is quite simple. The amount of missing data points in the file (about 30%) is way too large. There are 332 missing single points with doppler speeds above 10 knots, that's roughly one every 30 seconds (I got the numbers by copying the track points table data from GPSAR, pasting them into a spreadsheet, and sorting by time difference and speed). So the decision to remove the post completely was definitely appropriate.




Check out this file posted with Garmin non approved device follow link and check out distance PB gpsteamchallenge.com.au/sailor/view/5501
Remember when i did 325 kms at lake catharabah and my gt31 didnt have sd card it only recorded 150km, every one knew i did it but post was removed because Peter cochrane flagged it ( so Ian told me so), One rule for everyone please

TRIMMER
QLD, 217 posts
28 Sep 2018 10:56AM
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Cocky2
QLD, 190 posts
28 Sep 2018 11:02AM
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Select to expand quote
AUS3333 said..





boardsurfr said..








Cocky2 said..
You will find a link to this file in an earlier post I made in the Topic.











Sorry I had missed that, thanks for posting it again. Here's a few things I noticed looking at the track. First, a comparison of the doppler and positional speeds for the entire track:

The "33 knot" region is where the green line is. What jumps out is that there are many spots where the positional speed is much higher than the doppler speed, up to 100 knots. That's unusual - for comparison, here is a recent Canmore track where there are only small differences:




It is quite common to see spikes in the speed graph during crash/swim episodes. Here is an example from another recent Canmore file (I used the Canmores as loaners for GPS competition at our East Coast Windsurfing Festival last week):




As theGPSlooses and gains reception, the position jumps a lot, and this sometimes "goes through" to doppler speeds. Similar artifacts while swimming/crashing can be seen with Locosys andu-bloxGPS units.

During the first hour of Callan's session, there are just two speed spikes, and they both seem linked to crashes (the first one is a "maybe"). Here is the second crash:

This is a clearcut case of a crash in a jibe, and did not affect doppler speed.

Now to the "33 knot" region:





This does not seem linked to a crash (Mike was correct in this assessment). But the speeds are quite spiky before the "33 knots", with large differences between positional speed and doppler speed. This indicates that the GPS did not get a good reception. The run was after a longer break or swim. There is a 60 knot spike in the speed graph about 80 seconds earlier, probably because the upper arm was completely in the water. It's likely that the armband moved during this break/swim so the GPS was below the arm, and/or that water got into the GPS.

Overall, though, the picture is quite simple. The amount of missing data points in the file (about 30%) is way too large. There are 332 missing single points with doppler speeds above 10 knots, that's roughly one every 30 seconds (I got the numbers by copying the track points table data from GPSAR, pasting them into a spreadsheet, and sorting by time difference and speed). So the decision to remove the post completely was definitely appropriate.









Check out this file posted with Garmin non approved device follow link and check out distance PB gpsteamchallenge.com.au/sailor/view/5501
Remember when i did 325 kms at lake catharabah and my gt31 didnt have sd card it only recorded 150km, every one knew i did it but post was removed because Peter cochrane flagged it ( so Ian told me so), One rule for everyone please






Dear Shannon/Trimmer- Aus 3333 or maybe you have more Seabreeze logins?

If you have any issues with my tracks report them to team challenge.
Not sure they would appreciate wasting their valuable time on unnecessary file checking.

I have all 3 files from the day both in KA and my computer which I am happy to send to GPSTC if requested.
They were also checked on GPS results before posting.
It was disappointing that the camore actually lost 4 KM after posting???
( Of course the Garmin can not be used to post and was not.
It is great device to use on the water compared to approved devices as I can read it. )

You can make any track public in KA you like.
KA track posting has nothing to do GPSTC.
If you read the post for my PB distance in GPSTC you can read the facts.

I have spent a lot of time with Dylan cleaning up over 200 poor files to improve the accuracy of the KA sailor for all Australia.
If you would like to waste more off your time looking at all my tracks in KA , go right ahead.

The GW52 made the distance with charging battery in the breaks but the memory did not.
The Canmore and GW52 are marked private in KA and the public one is the one I have chosen for Sailor Score as it is more accurate than the Canmore. This has nothing to do with my post to GPSTC.
The GW 52 gave me less sailor score as it did not have the full distance.





TGale
TAS, 301 posts
28 Sep 2018 11:15AM
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^^^ Is that Garmin accurate - you should have burnt some calories sailing 315km??

Cocky2
QLD, 190 posts
28 Sep 2018 11:24AM
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TGale said..
^^^ Is that Garmin accurate - you should have burnt some calories sailing 315km??




Yes the Garmin was accurate. More accurate than the Canmore and lasted longer than the GW52.
It was a great day sailing with mates who also got PB's for distance. Bananas are the best for distance days.

AUS3333
31 posts
28 Sep 2018 9:55AM
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Cocky2 said..

TGale said..
^^^ Is that Garmin accurate - you should have burnt some calories sailing 315km??





Yes the Garmin was accurate. More accurate than the Canmore and lasted longer than the GW52.
It was a great day sailing with mates who also got PB's for distance. Bananas are the best for distance days.


I don't know the facts but others here will jump in i hope.
Only recently was canmore approved but when you did this post the canmore was not allowed for contribution of team scores.
Check
Is there rule bending going on here or just rule changing to suit certain people.
I have never checked anyone's file or flag a one, this forum is a giggle if anything

Cocky2
QLD, 190 posts
28 Sep 2018 12:12PM
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Select to expand quote
AUS3333 said..

Cocky2 said..


TGale said..
^^^ Is that Garmin accurate - you should have burnt some calories sailing 315km??






Yes the Garmin was accurate. More accurate than the Canmore and lasted longer than the GW52.
It was a great day sailing with mates who also got PB's for distance. Bananas are the best for distance days.



I don't know the facts but others here will jump in i hope.
Only recently was canmore approved but when you did this post the canmore was not allowed for contribution of team scores.
Check
Is there rule bending going on here or just rule changing to suit certain people.
I have never checked anyone's file or flag a one, this forum is a giggle if anything


#The Canmore has been approved for use as it sits somewhere in between those already mentioned. It has the potential accuracy of the GT-31 as it is a Doppler based device, but it has very limited verifiability. If you are posting results that are counted in the team challenge in a competitive team you should inspect the results closely in a stand-alone analysis program (GPS-Results/GPSAR-Pro/RealSpeed) for unusual results and errors. Preferably, team captains or the team 'tech guru' should help with this, and if there is any doubt the files should be sent to one of the GPS-TC technical advisors for a second or third opinion.

decrepit
WA, 12776 posts
28 Sep 2018 10:15AM
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Thanks Peter, looks like I need to be more thorough with my checking.

AUS3333
31 posts
28 Sep 2018 10:32AM
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Select to expand quote
Cocky2 said..

AUS3333 said..


Cocky2 said..



TGale said..
^^^ Is that Garmin accurate - you should have burnt some calories sailing 315km??







Yes the Garmin was accurate. More accurate than the Canmore and lasted longer than the GW52.
It was a great day sailing with mates who also got PB's for distance. Bananas are the best for distance days.




I don't know the facts but others here will jump in i hope.
Only recently was canmore approved but when you did this post the canmore was not allowed for contribution of team scores.
Check
Is there rule bending going on here or just rule changing to suit certain people.
I have never checked anyone's file or flag a one, this forum is a giggle if anything



#The Canmore has been approved for use as it sits somewhere in between those already mentioned. It has the potential accuracy of the GT-31 as it is a Doppler based device, but it has very limited verifiability. If you are posting results that are counted in the team challenge in a competitive team you should inspect the results closely in a stand-alone analysis program (GPS-Results/GPSAR-Pro/RealSpeed) for unusual results and errors. Preferably, team captains or the team 'tech guru' should help with this, and if there is any doubt the files should be sent to one of the GPS-TC technical advisors for a second or third opinion.


That's fine but my question is was that the case when you posted?

tbwonder
NSW, 733 posts
28 Sep 2018 1:59PM
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Not sure of the exact date, but here is a post from Sailquik from June 2015




Hroar
QLD, 125 posts
29 Sep 2018 7:09AM
Thumbs Up

Select to expand quote
AUS3333 said..

boardsurfr said..




Cocky2 said..
You will find a link to this file in an earlier post I made in the Topic.







Sorry I had missed that, thanks for posting it again. Here's a few things I noticed looking at the track. First, a comparison of the doppler and positional speeds for the entire track:

The "33 knot" region is where the green line is. What jumps out is that there are many spots where the positional speed is much higher than the doppler speed, up to 100 knots. That's unusual - for comparison, here is a recent Canmore track where there are only small differences:




It is quite common to see spikes in the speed graph during crash/swim episodes. Here is an example from another recent Canmore file (I used the Canmores as loaners for GPS competition at our East Coast Windsurfing Festival last week):




As theGPSlooses and gains reception, the position jumps a lot, and this sometimes "goes through" to doppler speeds. Similar artifacts while swimming/crashing can be seen with Locosys andu-bloxGPS units.

During the first hour of Callan's session, there are just two speed spikes, and they both seem linked to crashes (the first one is a "maybe"). Here is the second crash:

This is a clearcut case of a crash in a jibe, and did not affect doppler speed.

Now to the "33 knot" region:





This does not seem linked to a crash (Mike was correct in this assessment). But the speeds are quite spiky before the "33 knots", with large differences between positional speed and doppler speed. This indicates that the GPS did not get a good reception. The run was after a longer break or swim. There is a 60 knot spike in the speed graph about 80 seconds earlier, probably because the upper arm was completely in the water. It's likely that the armband moved during this break/swim so the GPS was below the arm, and/or that water got into the GPS.

Overall, though, the picture is quite simple. The amount of missing data points in the file (about 30%) is way too large. There are 332 missing single points with doppler speeds above 10 knots, that's roughly one every 30 seconds (I got the numbers by copying the track points table data from GPSAR, pasting them into a spreadsheet, and sorting by time difference and speed). So the decision to remove the post completely was definitely appropriate.





Check out this file posted with Garmin non approved device follow link and check out distance PB gpsteamchallenge.com.au/sailor/view/5501
Remember when i did 325 kms at lake catharabah and my gt31 didnt have sd card it only recorded 150km, every one knew i did it but post was removed because Peter cochrane flagged it ( so Ian told me so), One rule for everyone please


Shannon I didn't flag your session, quite a few of us talked about including Anne the Vikings captain who couldn't be bothered looking into and was happy to let it go to my disgust, apart from what was on the screen of your gt31 you could not produce a two files to prove it as are the rules in GPSTC when you are going for a Pb. You only have yourself to blame if you didn't think to put a SD card in your GT31 & carry a Canmore GP102 as backup. If you don't re-zero a GT31 after every use the distance odometer keeps adding up and Max speed stays in there as well. I'm sure Daffy & Decrepit will agree with this as has constantly been discussed off late in these forums.
Thankyou, Peter Cochran.

Cocky2
QLD, 190 posts
29 Sep 2018 7:43AM
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tbwonder said..
Not sure of the exact date, but here is a post from Sailquik from June 2015





Thanks Andrew however most People who read rules and follow them do not post unfounded comments on Seabreeze.

When I started in May 2015 I ordered 2 Canmores as there was nothing else.

TRIMMER
QLD, 217 posts
29 Sep 2018 10:37AM
Thumbs Up

Select to expand quote
Hroar said..

AUS3333 said..


boardsurfr said..





Cocky2 said..
You will find a link to this file in an earlier post I made in the Topic.








Sorry I had missed that, thanks for posting it again. Here's a few things I noticed looking at the track. First, a comparison of the doppler and positional speeds for the entire track:

The "33 knot" region is where the green line is. What jumps out is that there are many spots where the positional speed is much higher than the doppler speed, up to 100 knots. That's unusual - for comparison, here is a recent Canmore track where there are only small differences:




It is quite common to see spikes in the speed graph during crash/swim episodes. Here is an example from another recent Canmore file (I used the Canmores as loaners for GPS competition at our East Coast Windsurfing Festival last week):




As theGPSlooses and gains reception, the position jumps a lot, and this sometimes "goes through" to doppler speeds. Similar artifacts while swimming/crashing can be seen with Locosys andu-bloxGPS units.

During the first hour of Callan's session, there are just two speed spikes, and they both seem linked to crashes (the first one is a "maybe"). Here is the second crash:

This is a clearcut case of a crash in a jibe, and did not affect doppler speed.

Now to the "33 knot" region:





This does not seem linked to a crash (Mike was correct in this assessment). But the speeds are quite spiky before the "33 knots", with large differences between positional speed and doppler speed. This indicates that the GPS did not get a good reception. The run was after a longer break or swim. There is a 60 knot spike in the speed graph about 80 seconds earlier, probably because the upper arm was completely in the water. It's likely that the armband moved during this break/swim so the GPS was below the arm, and/or that water got into the GPS.

Overall, though, the picture is quite simple. The amount of missing data points in the file (about 30%) is way too large. There are 332 missing single points with doppler speeds above 10 knots, that's roughly one every 30 seconds (I got the numbers by copying the track points table data from GPSAR, pasting them into a spreadsheet, and sorting by time difference and speed). So the decision to remove the post completely was definitely appropriate.






Check out this file posted with Garmin non approved device follow link and check out distance PB gpsteamchallenge.com.au/sailor/view/5501
Remember when i did 325 kms at lake catharabah and my gt31 didnt have sd card it only recorded 150km, every one knew i did it but post was removed because Peter cochrane flagged it ( so Ian told me so), One rule for everyone please



Shannon I didn't flag your session, quite a few of us talked about including Anne the Vikings captain who couldn't be bothered looking into and was happy to let it go to my disgust, apart from what was on the screen of your gt31 you could not produce a two files to prove it as are the rules in GPSTC when you are going for a Pb. You only have yourself to blame if you didn't think to put a SD card in your GT31 & carry a Canmore GP102 as backup. If you don't re-zero a GT31 after every use the distance odometer keeps adding up and Max speed stays in there as well. I'm sure Daffy & Decrepit will agree with this as has constantly been discussed off late in these forums.
Thankyou, Peter Cochran.


Hey mate i don t care about the whole thing my point is ian said it was you.
I still kick your both your arses side by side.
Bring it on, the two of you are as bad as each other

boardsurfr
WA, 2454 posts
29 Sep 2018 10:13AM
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Hroar said..
... apart from what was on the screen of your gt31 you could not produce a two files to prove it as are the rules in GPSTC when you are going for a Pb.


There is no requirement for multiple files for PBs on GPSTC. Actually, there's no requirement to ever wear two devices, just a suggestion:
"users are encouraged to use multiple GPS's if they wish to have backup redundancy".

You seem to be refusing the GPSTC rules with the "record rules" from GPS-speedsurfing.com, which require two approved and identical devices for "official" record attempts.



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Forums > Windsurfing   Gps and Speed talk


"Devices for GPSTC in Rules page" started by Cocky2