Editing Motion capture (section)

===Radio frequency positioning===
Radio frequency positioning systems are becoming more viable{{Citation needed|date=October 2017}} as higher frequency radio frequency devices allow greater precision than older technologies such as [[radar]]. The speed of light is 30 centimeters per nanosecond (billionth of a second), so a 10 gigahertz (billion cycles per second) radio frequency signal enables an accuracy of about 3 centimeters. By measuring amplitude to a quarter wavelength, it is possible to improve the resolution down to about 8&nbsp;mm. To achieve the resolution of optical systems, frequencies of 50 gigahertz or higher are needed, which are almost as dependent on line of sight and as easy to block as optical systems. Multipath and reradiation of the signal are likely to cause additional problems, but these technologies will be ideal for tracking larger volumes with reasonable accuracy, since the required resolution at 100 meter distances is not likely to be as high. Many scientists{{Who|date=October 2017}} believe that radio frequency will never produce the accuracy required for motion capture.

Researchers at Massachusetts Institute of Technology researchers said in 2015 that they had made a system that tracks motion by radio frequency signals.<ref>{{Cite web|url=https://www.nydailynews.com/news/national/mit-creates-device-track-people-walls-article-1.2419781|title=MIT researchers create device that can recognize, track people through walls|last=Alba|first=Alejandro|website=nydailynews.com|date=November 2015 |access-date=2019-12-09}}</ref>