Loran,

The concept isn't as new as your post might suggest. There are three
contenders in this:

- Surecheck with the Trafficscope vr (no altitude readout) and vrx
(altitude readout)
- Monroy Aero's ATD-300 (altitude readout)
- Proxalert's R5 (altitude readout)


--
Thomas Borchert (EDDH)