Hello Steve,
The “validity” field is used by sender server to indicate the confidence that the values of the tracker are (still) valid and may depend on the sender’s interpretation. This field is usually either 0% or 100% for deterministic tracker like virtual trackers or trackers generated from deterministic sources (like motor encoding). When the tracker is generated from probabilistic sources, e.g., from image analysis, it can vary between 0% and 100%. However, it is up to the sender to calculate and assign a meaning to this value and some software might always set it to 100% as long as it detected a tracker somewhere even though it is probabilistic.
For example, with our tracking product (VYV Albion), the “validity” of trackers generated from our tracking cameras depends on the amount of cameras that sees the tracker and how much time passed since the last time a camera detected the tracker (in case of temporary occlusion or detection delay).
I hope it answers the question. Do not hesitate to ask for more details if needed.
Regards,
Gilles-Philippe
