[appreciatorBus]

The information broadcast by transponder is significantly more precise than what you will get with radar, microphone array, or binoculars.

GPS Lat & Long Barometric Altitude Ground speed & track angle Rate of climb/descent

All updated every second or so.

[phantasmish]

I can just about guarantee it has nothing to do with targeting and a lot to do with making Venezuela unsure when strikes are about to start, both for security of the forces launching the eventual strikes (if any) and to harass/wear-down Venezuelan air defenses by keeping them very alert.

If our aircaft were flying transponders-on during all these exercises then suddenly went dark, it’d signal imminent attack. This keeps them guessing. Possibly we’re even playing around with having them on some of the time for some aircraft, and off at other times.

We don’t do that with AWACS and such near Russia because we’re not posturing that we may attack them any day now, and want to avoid both accidental and “accidental” encounters with Russian weapons by making them very visible. In this case, an accidental engagement by Venezuelan forces probably isn’t something US leadership would be sad about.

[FireBeyond]

I live near JBLM in Washington. I am routinely overflown by helicopters and planes (C-17s) often with their transponders off (I have an ADS-B receiver running on a VM). These are training flights that are not going anywhere outside of the Puget Sound region. For added fun, I'm also pretty close to several Sea-Tac approaches.

[themafia]

> is significantly more precise than what you will get with radar

Is that increase in precision much larger than the plane itself? If it's not then it couldn't possibly matter in this application.

Further radar is not a static image. The radar is constantly sweeping the sky, taking multiple measurements, and in some cases using filtering to avoid noise and jitter.

> GPS Lat & Long Barometric Altitude Ground speed & track angle Rate of climb/descent

You get or synthesize every one of those with radar as well.

[inferiorhuman]

Yes, ADS-B is significantly more precise than civilian primary radar returns. That's why the FAA is trying to move away from radar. The JetBlue near miss was about 150 miles from Curacao ATC which is beyond what most ASR systems cover (around half that).

Military radar is a different beast, but even then you're still trying to figure out what the returns mean. ADS-B explicitly says hey there are two aircraft in a tiny space. Civilian radar is likely not precise enough to identify two aircraft that close.

[rkomorn]

Isn't altitude information also one of the important things about ADS-B that radar lacks?

Although ADS-B is self reported and "vulnerable" to bad/spoofed info.

My CFI and I once saw ADS-B data from one of the startups near Palo Alto airport in California reporting supersonic speeds... at ground level, no less.

Edit: still have it in my email, heh. It was a Kitty Hawk Cora, N306XZ, reporting 933kts at 50'.

[inferiorhuman]

Civilian vs military. The military can get altitude information from primary radar.

[trhway]

Even good stereopair like a WWI navy guns rangefinder, will give you all that info, of course not precise enough to lock a missile - well, transponder also wouldn't let you to anyway, and thus all that transponder precision is pointless in that context.

[baq]

A missile only needs to get close enough for its sensors to take over for the final approach right? Transponder data should be quite enough for that, especially for a kc-46

[trhway]

Any of the methods i mentioned is enough to get missile close, except may be microphones as limited speed of sound means that the plane would have moved significantly from the observed position, though again even that would have allowed to put missile into the vicinity and in general direction.

Watching Ukraine videos there is new game in town though - relatively cheap IR cameras. Using IR, day or night, you can detect a jet plane from very large distances and just guide missile to the plane computer-game-joystick style.