Couple of weird mode S codes at KFDK today

[ur20v]

These popped up briefly today at KFDK, but were gone as quickly as they appeared. Gatwick and airframes had nothing on them, so I'm a little stumped. Any ideas?

-278C99

-278E86

 

[kma371]

Those are most likely plots from ground-based radar. There was a list on the thread here somewhere which Define certain groups of codes and what area they cover but I can't find it at the moment

 

[kma371]

Found it

http://forums.radioreference.com/aircraft-data-decoding/319894-what-they.html#post2448272

According to the chart, those are TIS-B plots from within the ZDC WASHINGTON CENTER AREA

 

[ur20v]

Ah, Thank you, I see now. Makes much more sense than the ideas I had swirling around my head. Interesting how it works, but it's too bad the TIS-B doesn't retransmit registration information.

 

[kma371]

Ah, Thank you, I see now. Makes much more sense than the ideas I had swirling around my head. Interesting how it works, but it's too bad the TIS-B doesn't retransmit registration information.

no problem. registrations would be helpful for us, but not really the pilots as they just need to know something is out there so as not to hit it