The positional accuracy of ADS-B as currently implemented is often measured in hundreds of meters, and GPS has never been particularly good at accurate estimations of altitude. Are drones to have ground based radar ranging? Altimeters based on barometric pressure? Updated to current altimeter settings via what means?
Anyone touting ADS-B as a realistic solution for avoiding mid-air drone collisions in congested areas is severely naive in my opinion, at least based on current technology. My assumption is that those advocating for it in this context aren't actually familiar with its specs and how it works.
In aviation, separation between flying objects is usually measured in miles horizontally, and a thousand feet or more vertically, and the systems are based on that reality for the most part.
> The positional accuracy of ADS-B as currently implemented is often measured in hundreds of meters, and GPS has never been particularly good at accurate estimations of altitude. Are drones to have ground based radar ranging? Altimeters based on barometric pressure? Updated to current altimeter settings via what means?
Some consumer drones use a radar altimeter to determine altitude AGL. The hardware is inexpensive. GPS is accurate for altitude in the US using WAAS (extremely small cost to use WAAS over traditional GPS).
> Anyone touting ADS-B as a realistic solution for avoiding mid-air drone collisions in congested areas is severely naive in my opinion, at least based on current technology. My assumption is that those advocating for it in this context aren't actually familiar with its specs and how it works.
Disagree. ADS-B was designed specifically for this circumstance (traffic avoidance).
Disclaimer: I have electrical engineering experience, a private pilot license with an IFR endorsement, and have worked on projects using ADS-B in production environments.
ADS-B just doesn't seem like a sensible solution. The only traffic you'll have is VFR, and they don't even require ADS-B out if they don't fly in controlled airspace. It seems that having ADS-B out would just clutter up the system and not be terribly useful.
I think the only viable solution would be to have sensors on the drones themselves -- visual and perhaps low-power radar. That way they should be able to avoid other drones and helicopters. It might be necessary to limit operations to VMC, although that shouldn't be much of an issue at below 500ft (you're only really going to be shut down during fog).
Anyone touting ADS-B as a realistic solution for avoiding mid-air drone collisions in congested areas is severely naive in my opinion, at least based on current technology. My assumption is that those advocating for it in this context aren't actually familiar with its specs and how it works.
In aviation, separation between flying objects is usually measured in miles horizontally, and a thousand feet or more vertically, and the systems are based on that reality for the most part.