On Sunday 13 September 2009, Rask Ingemann Lambertsen wrote: > On Sat, Sep 12, 2009 at 07:50:26PM +0200, Ivo van den Maagdenberg wrote: > > The use case is as follows: take the openmoko and make it a cycleway > > shock measuring platform, utilizing the accelerometers. So, direct reads > > from the are going to be needed. The gps unit is of course of interest to > > make the measurements location-based. > > I've had an idea along the same lines: Use accelerometer data to log the > position of points during a train ride. Only, I'd need GPS readings that > are accurately timestamped, i.e. not rounded to whole seconds.
I think you can get the more accurate timestamp if you talk to the GPS direct in UBX format as omgps can. I don't remember whether the NMEA output uses integer or fractional seconds on this unit. Gypsy uses integer seconds since epoch as its timestamp, and I think this is where the rounding occurs. fso- gpsd reads from gypsy so inherits the rounding. Out of interest why you want to know the position of the points, and how do you intend to distinguish them from a lateral track defect? As a former railway test engineer I'm interested. _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community