GPS Position Accuracy

Fit data records regardless. Just like you ride and into a tunnel, it will still record but you will see speed drop or no map etc. 

if you want to get the gpa accuracy data every second, you can write into the fit file using fit contributor and just update the gos accuracy info into a graph and use that as overlay to the speed graph. Will do what u want but still don’t quite understand your use case. 

Thanks, there are a bunch of organisations holding speed based races where the highest speed / highest average speed wins the competition. The readings must be GPS based, and the GPS level of accuracy must be shown or known by the organisation in order to register the GPS and  in order for the GPS to be accepted into the competition. They need some way to know what the speed dilution precision is  associated with any submitted official GPS readings.

I think what you suggested is the easiest way.... because you should be able to see straight away if the readings were valid during the time period they were taken.

Thanks for the advice !

One thing to note while testing, is that when playing back a .fit in the sim, the accuracy doesn't vary based on what's in the .fit, but what's set as the GPS quality in the sim.  So if you set the quality to be "good", get there's a complete GPS loss in the .fit, it will still show as "good" to your app.

okie.. thanks for the explanation. Kinda weird that they are using GPS to get the speed numbers tho. Or are these races like virtual ones and it's based on user integrity and things like that? (kinda like zwift)

Not any other way to get speed on a windsurfer then GPS.

They have also asked is there a way to get the actual figure..... the software must be calculating it somewhere, but position.info just tells you if it's below 3.... is there any way to read the actual calculation. ? 

There's not a way from CIQ.  All you see are the 5 possible levels of quality/accuracy

That's what I feared.... Time for a change request

It's been requested many times in the past, with info like the #of sats and the accuracy in distance.  This is available with native stuff on some non-wearables, but has never been exposed to CIQ.

With the newer GPS chipsets, I think it was DCR that said that devices might not be as accurate, but the chips require less power, so it helps with battery life.  Keep in mind that the accuracy is such that it works for the native activities, but maybe not as exact as you require, but that also ties into the HW itself.

Thanks Jim, the windsurfing group are now asking me very technical questions about the Dilution of Precision Quality value of less than 3, and the default Garmin speed readings in connect IQ.

They  wanted to know if the Garmin speed readings were made using true Doppler calculations rather than filtering of two positions, because doppler based speed readings are significantly more accurate than using a position filter which is effected by the DOP error.. If they are doppler readings, how can we know the errors?

They also asked what the number 3 actually reflected in terms of a position calculation, ie is it 3 meters Does anyone know this technical info>?

yes. someone knows. 

That someone is Garmin and you'll be hard pressed to be able to obtain this info.