Not sure if this has been answered. Just curious... All of us regularly see decodes on 'craft that decline to have info listed on their ads-b system for whatever reason. I regularly see many altitude only decodes, etc. My question is: Do "fragment information" lines like this fed to exchange have any value, or are these lines simply discarded by the gathering software?
Looking at the dump1090 output, I see lines of 'craft that some time only show the altitude and nothing else listed. There are military 'craft around here so I just figured that they set up their tracking to omit information.
Interesting. If you can send me them when they pop up I can investigate ... So mode-s then ... they should be MLAT'd then ...
Will do, I guess I can take a screenshot and attach it to my reply. Have to go now, but will do it later in my day.
Some are Mode-S possibly, some might even be mode-c if you are passing --modeac https://mode-s.org/decode/ It is what it is .... see A43B67 .. https://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=N327BW https://flight-data.adsbexchange.com/map?icao=A43B67&date=2019-01-23 It takes a lot of messages, no errors, and proper decodes to get all the information.
I don't have the -- modeac enabled. I think your last line in the post is the key to the situation. The fact is that it is a radio signal after all, and is subject to fading, dropout, electronic interference at the receiving end, type of receiver, etc. I should have thought of that. Thanks for passing along the associated links.
