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Tracking accuracy and refresh rate


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I've been developing for the Vive for a couple of years now and every now and then I get questions about accuracy and refresh speed.

My application is a baseball training and it works with a controller or with a tracker on an actual bat. When people try to hit high speed pitched balls the controller or tracker moves quickly as well. And when people miss the ball they sometimes wonder if the accuracy of the system is good enough for such high speed tracking. One of the features in the training is that I show the path of the bat during the swing and also there I notice strange results when I move the bat at high speeds, particularly when using a tracker. The bat position jumps and sometimes the bat is rotated as well. My initial thought was that maybe with the tracker at the knob of the bat it would be shielded from the lighthouses (or at least from one of them), but I tested it with different setups (both lighthouses in front of me, for example) and that made no difference.

So I'm trying to understand what could be the reason and for that I would like to know the tracking speed and accuracy of the system. Is tracking a baseball bat moving at 80mph at all possible using a Vive tracker? 80mph means 35 meter per second, so 3.5 cm per milisecond. So with a refresh rate of 1000Hz the tracker will move 3.5 cm between measurements. I found a couple of answers on reddit and  from that I understand that it is a combination of IMU tracking and lighthouse tracking, but I can't find any clear answer on how many times per second the position and rotation is updated. I also found this post from Nasa https://ti.arc.nasa.gov/publications/61557/download/ talking about accuracy, but I can't find any clear info on the Vive site. And the reddit posts are a couple of years old, so are they still accurate?

So I hope someone can point me to specs from HTC or can answer this in this post. Especially about the accuracy, as the paper from Nasa shows that for a moving tracker the accuracy decreases drastically (43 mm , 4.3 cm off is a lot when you try to hit a fast-moving virtual baseball). And is there a difference between the version 1.0 base stations and trackers and version 2.0? I currently have version 1 trackers (or even developer kit trackers 🙂).


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