GPS and magnets.

[keithski122]

I bought a cheap gps speedo for my scooter as I don't trust the factory unit, if I mount it using strong magnets will it upset the signal?

 

[voipio]

No. But if it contains an integral magnetic compass, as some do, then yes, the magnetic compass reading will be affected.

Adjacent metalwork can have effects on GPS signal reception, especially if the metalwork is close to the GPS receiving antenna, but that would occur with or without any magnets being near. The GPS antena is usually a square patch mounted inside at the top of the unit.

Bear in mind that GPS-based speedometers cannot really be relied on for absolute accuracy, because of the positional drift that occurs with GPS position estimates. They can often be in error by a couple of mph, epecially if there are high buildings, or vehicles around, or atmospheric disturbances are present.

 

[keithski122]

No compass, not that I would use it, just want the speed function to work.

 

[Ubique]

Most portable GPS receivers (Garmin etc.) have an optional external antenna that has a magnetic base, if your GPS receiver gives you a positional accuracy radius, then the smaller the figure, the better the speed accuracy will be.

 

[keithski122]

Most portable GPS receivers (Garmin etc.) have an optional external antenna that has a magnetic base, if your GPS receiver gives you a positional accuracy radius, then the smaller the figure, the better the speed accuracy will be.

All in one unit with no optional external antenna.

 

[pedrobedro]

Bear in mind that GPS-based speedometers cannot really be relied on for absolute accuracy, because of the positional drift that occurs with GPS position estimates

They have to be better than manufacturer units which always read higher than actual speed.