Not exactly new: here's one small UK based company but a Google search throws up thousand of them. I was involved in an early attempt at this in Australia. Unhappily, our rather large system proved too tempting a target for rifle users and they got shot up. Must have been an anemometer on the top, spinning away. This was pre-Internet, so we used meteor trails as "mirrors" to bounce signals: transmita constant signal, when the sensor picks it up its empties its bowels and that bounces off the ion trail.