GPS Time shift

[richib2002]

I have just fitted a 10hz GPS module to a Drag car. This is mainly for a speed signal. The trouble is in i2 standard there is not a GPS time shift facility when in a "Drag Race" project. Has this been omitted for a reason or is it just an oversight?

Regards

Rich

[Martin]

Is the 10Hz new?

Where did you get it?

[richib2002]

Brand new from Motec Europe last week. GPS speed signal is around 0.2 of a second out

[Martin]

With what did you compare it?

What make of GPS is this?

[Chris]

Yes the GPS Corrections is not in the Drag Racing standard project. Adding that feature is on the to do list, but I do not have any time frame for when this will be completed.

The 10 Hz GPS is likely a unit made by MoTeC Systems USA. You can find a spec sheet online by changing your region in the bottom right corner of the screen, then going under downloads/datasheets and selecting the RaceGrade GPS
http://www.motec.com.au/filedownload.ph ... docid=2745

The time shift should be -0.13 for the 10 Hz model and -0.11 for the 20 Hz model, based on my testing.

Chris Brown

[Holmz]

Yes the GPS Corrections is not in the Drag Racing standard project. Adding that feature is on the to do list, but I do not have any time frame for when this will be completed.

The 10 Hz GPS is likely a unit made by MoTeC Systems USA. You can find a spec sheet online by changing your region in the bottom right corner of the screen, then going under downloads/datasheets and selecting the RaceGrade GPS
http://www.motec.com.au/filedownload.ph ... docid=2745

The time shift should be -0.13 for the 10 Hz model and -0.11 for the 20 Hz model, based on my testing.

Chris Brown

Chris,
Good info.
Is the GPS speed:
1) differenced between the current position and the last position,
2) using some doppler
3) or ??

[jhidley]

What are the units of time shift for the 10Hz Race Grade GPS unit? Seconds or msec? The field available for this time shift has a default unit of msec.

[Chris]

I believe that GPS speed is based off doppler effect and not the positional information.

The time shifting required in the prior post was listed in seconds, hence -0.11 seconds (110 msec) for our 20 Hz model and -0.13 seconds (130 msec) for the 10 Hz model.

[jhidley]

Chris,

Thanks.