Manual Track Mapping

yoshiboldor

Don’t know if this has been asked before (could not find it). But can you map the track but driving around the inside, then the outside of the track? The idea being to be able to look at your laps and see the actually line taken in relation to the track boundaries?

aol_of_RaceChrono

It's been asked, but rather infrequently. Problem is, the reasonably priced GPS systems lack accuracy to make such feature useful.

yoshiboldor

It’s just that i know race guys with some commercially available systems and this is how they do it.
It would be handy if it was possible.
When i tried the system it seems to show up enough accuracy to show my line v’s my mates line, but i could not see where we were in relation to the track edge. So it “looks” like it is accurate enough to work?

How good would the GPS need to be to make it useful? I have a 5Hz GPS.

David Lundin

I doubt any 5Hz GPS will be anything near accurate enough unfortunately. But how about if you drive multiple laps on the inside and multiple laps on the outside? Could some clever interpolation be used to get a good track?

yoshiboldor

So what is the resolution of a 5hz gps as far as location goes??

Adamw

I think most of the comercial track mapping loggers also use input from lat/long accelerometers and wheel speed sensors to further enhance the accuracy of the location.

The MTKII based GPS like Qstarz have a quoted accuracy of +/-3m, but there are also errors on top of this due to the update rate.

David Lundin

Compare to a pro solution like eg. a VBox 3i RTK: http://www.racelogic.co.uk/?show=VBOX-Products-VBOX_3i_RTK

It not only uses GPS, but also the russian satelite system Glonass, as well as radio link to a separate base station.

I bet it costs a *bit* more then a QStarz or other 5Hz GPS though :-)