Track log altitudes


#1

I have noticed the wierd altitude readouts from the track logs. I searched the forums and found this post.
http://discussions.flightaware.com/viewtopic.php?t=2179&highlight=altitude

mduell, let me see if I understand your explanation.
Fligth is talking to ATC facility ABC and level at FL350. ABC hands flight off to XYZ facility who then issues a descent clearance. Aircraft starts down and ABC’s radar still sees the flight but reports the altitude as the previous when it was in ABC’a airspace? Do I have that right?


#2

It’s not necessarily related to a handoff. Here’s an explanation of what we’re seeing:

For a flight over New York, we’ll be receiving radar position reports every minute from a radar facility in the vicinity of the flight. When that flight is assigned a new altitude, we’ll receive one (and sometimes more) position report from a different facility, claiming the flight is at that new assigned altitude. Sometimes that second radar site will be nearby, but sometimes it’s across the country. We’re working on some logic to ignore those bogus position reports, but we’re being careful so we don’t accidentally discard any real position reports.


#3

That is what I thought. Thanks.