Over the last several minutes, the Tracker has said Mimi has gone from 1MPH to 3MPH to 4 MPH to 6 MPH to 3MPH, back to 4MPH.
Look Markus will probably confirm this, that the only way one has a chance in this long of distance is to maintain steady pace for hours on end, and definitely not be frequently spurting up to 6MPH. It almost suggests they are using somebody on a bicycle that is trying to gage speed.
That, or the RaceDrone is next to worthless for speed, as evidently, the Company man has already admitted.
Should have gone with Garmin! You know the old saying, "Nobody got fired for buying IBM." Duh, they are only trying to establish a World Record here. Why did they chintz on one of the most important pieces, the live tracker?!?
Both the RaceDrone tracker as the Garmin Delorme that Sandy is using, are useless for speed indications. Both use satellites to define their current position, the difference is that the RD tracker uses the mobile network to send that position to the server, while the Garmin uses also satellites to send that position. This means that when there is no mobile coverage, the Garmin has the advantage (but it has other disadvantages compared to the RD tracker, such as GPS precision, weight, and other things).
The Garmin Delorme takes a position every 2 minutes (which is the most expensive monthly payment plan Garmin offers), and I assume that the RD tracker has the same or a similar time interval to take positions. Compared to a gps watch which takes a position every second, this explains why you can not accurately measure speed with a gps tracker.
The question was asked before why using a gps tracker then. Simple answer, only to know where somebody is located at that moment, which then is used as a safety tool in ultra races, as a spectator tool to see 'live tracking' and in attempts like Sandy's and Mimi's to show the public where they can find the runners if they want to join them for a run. Nothing more, nothing less...
For data like speed, cadence and things like that, both runners are wearing a gps watch, from which they then provide the data (in a non-realtime mode).