GPS Speed Not Correct during Corners

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Searya
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GPS Speed Not Correct during Corners

Post by Searya » Mon Oct 19, 2020 5:29 pm

I am having a problem where the GPS speed in the corners is inaccurate. I am using the Elf 10hz gps with my iphone XR and watching the speeds via the video replay.

On straights all seems good but when going into turns into sharp turns the speed becomes too low. For example, in my video from this weekends event I would go through the turn at a consistent 55mph but the speed displayed would drop down to as low as 17mph.

Any ideas on how to improve the readouts?
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Harry
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Re: GPS Speed Not Correct during Corners

Post by Harry » Mon Oct 19, 2020 6:54 pm

This speed values are as delivered by the BadElf. Speed from GPS is a frequent issue - even for 10 Hz devices. Although I doubt there are options to change this immediately and in the first place, please contact Bad Elf support. When talking to them, please make sure they understand that the data recorded is 1:1 from their device and not adjusted by LapTimer. LapTimer has an additional feature to compute speed from position changes instead of using the speed value delivered (and measured using the Doppler effect). While this calculated values will change more instant, they may be pretty noisy. Please try for the Elf. LapTimer ‣ Administration ‣ Settings ‣ Expert Settings ‣ GPS Tweaks / Speed ‣ Calculated

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Searya
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Re: GPS Speed Not Correct during Corners

Post by Searya » Mon Oct 19, 2020 7:42 pm

Thanks I will hit up BadElf to see what they have to say.

Will switching to calculated work after the recording is done or is it a setting that needs to be on before running the lap in order to take effect.
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Harry
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Re: GPS Speed Not Correct during Corners

Post by Harry » Mon Oct 19, 2020 8:52 pm

Again, this needs to be set ahead of recording. But simply switch it and use Analysis ‣ Realtime ‣ GPS to see speeds reported in real time. No need to do this on track, it can be done on public roads.

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