For decades, controllers relied on position reports over high-frequency radio every hour or so, competing for air time with fishing vessels and all kinds of other traffic.
High resolution is achieved by measuring motion rather than radio frequency signals as wifi does, and is based on where and how the person moves through an environment overtime.
"While a 150, 000-170, 000 per month trend in payrolls is far from booming, it is strong enough overtime to keep the unemployment rate moving down, " said Jim O'Sullivan at High Frequency Economics.