Forum: General Topics

Hi Ian,

Crikey, that must be one of the 'noisiest' tracks I've seen!

I think what you're getting there simply shows the rubbishness of the internal GPS on the 8900! So it is normal, albeit very frustrating! I've had similar spikiness myself, and I now very rarely use the internal GPS, instead using a separate bluetooth device, which gives a far superior track.

You were probably a bit unlucky to get such a noisy track though - the GPS satellites are constantly moving across the sky, so there are times when fewer are visible, which makes it harder for the phone to get a good fix. Maybe this was the case last night. Do you find that the location accuracy varies at different times?

Were you hand-holding the phone, or was it in a pocket. I think I read somewhere that the GPS antenna is at the bottom of the 8900, beneath the space bar, so making sure that this has a clear view may help. Also, did you first turn TMJ on during the walk, or when stationary (and outside) at the start. I've found with other devices that they often get a better/more reliable fix if left stationary outside for a couple of minutes after switching on.

One thing you can do in TMJ to help reduce the spikiness when walking is set the Activity Profile/Max Track Speed to say 5mph, which will stop any trackpoints from being stored if the current speed is above this threshold. This can give quite a dramatic improvement in removing the spikes, although if the signal is excessively spiky (as in your case), it could result in parts of the track not being recorded at all. Worth experimenting with though. (Don't forgot to change profile if you then get in a car/bike etc - otherwise you'll end up with nothing being recorded!)

Cheers,
Stephen

(ps: Don't worry about the CellID settings - they won't make any difference to the GPS signal)

Hi Ian,

The altitude capping is very odd. Looking in the server logs there are a substantial number of trackpoints (from all users) with an altitude of precisely 6054.00m. Further investigation suggests that these have all come from BlackBerry phones, so I'm wondering if it is perhaps a limit imposed by the phone, rather than an issue in TMJ. I was about to suggest that next time you fly to check the BlackBerry's built-in GPS status (Options/Advanced Options/GPS), but looking at my own 8900 this doesn't actually show an altitude readout, only latitude and longitude :-(

One other thing you might try (to at least eliminate TMJ as the cause) is to enable GPS Logging and set the TMJ Menu/GPS/Log Options/Log Type to Raw GPX. This log file should then show whether the altitude is being provided correctly by the phone and then TMJ is doing something strange, or whether the phone itself is the issue.

(I have definitely correctly recorded a higher altitude using an external GPS device, but that was in 2007, so there may be another bug introduced since!)

With the subscriptions I'm not really able to offer a lifetime license, as the vector maps and TMJ website generate ongoing costs that I have to cover. However a reduced renewal price does sound reasonable, I'll bear this in mind!

Cheers,
Stephen