I have been watching this Military Boeing RC-135W do touch and goes at MCI airport on ADSB and this unknown aircraft kept showing up underneath or near this one. what would this be? see screenshots.
Sorry i didn't. I almost clicked on them. Edit, I just looked at the links. I'm not sure what i read. its' pretty technical.
Hmm ADS-B .... Maybe a 2nd transponder using ModeC or ModeS only ... and you see it via TIS-B. Anyhow ... the text somewhat still applies. They don't typically do touch and goes in formation so it's gonna be the same aircraft 99%.
I figured it was the same aircraft of some sort. I see what you mean on the right side of the screen where the filters are. I filter the TIS-B on and only see that one. I didn't get anything filtering Mode C or Mode S.
So for ModeS you require 4 receivers for multilateration as no location is sent, then it will be shown as MLAT. Quite likely that we might not have 4 receivers participating in MLAT seeing aircraft at low altitude in that area. ModeC only gives squawk / altitude and no hex id https://en.wikipedia.org/wiki/Aviation_transponder_interrogation_modes#ICAO_24-bit_address While theoretically possible it's not practical for adsbexchange to do MLAT on ModeC, so you'd never see that. Now as you might have read up on TIS-B is data by ATC which has secondary radar. Thus this target could be either ModeS or ModeC. Or the ATC system is mistaken and thinks the transponder has no ADS-B which would also mean the target is displayed as TIS-B. Maybe i'll add some stuff on the wiki -.- https://github.com/adsbxchange/wiki/wiki/TIS-B---MLAT
not intending to get off topic, but @wiedehopf i think you should also include some basic info on why you might see a plane in the sky, and it should be there, as there are other aircraft near it being detected perfectly fine. Mode 5 and its encryption that no one can detect. Also, for some aircraft flying in tight formations, that only 1 aircraft will broadcast to prevent flooding ATC with TA/CA Alerts, but they know they are there with respect to the number of aircraft in the formation.
