Incomplete data tags, broken lines, you name it


#1

Theses bugs are the most common for me when I use FlightAware.

This image shows how tracks for flights strangely disappear and often appear broken and stuck like this for the majority of the flight:

http://img23.imageshack.us/img23/1371/4152009121525pm.jpg

Two things going on in this picture. Starting from the furthest left red circle is how (in this example) COA664 has an incomplete data tag showing only the destination (MMUN) and not the departure field (KIAH). The problem shows up again for TCF7582, so I know it doesn’t have to do with the fact that it is an international flight. BTA3023 and COA1667 have the same problem, except that they show up in blue because they are arriving into IAH (otherwise they would be green as well).

http://img9.imageshack.us/img9/4179/4152009122241pm.jpg

There is probably some megathread or something already posted about this, but it’s been like this for a while and still hasn’t been fixed. [edited because I think I came off rude. Sorry! I love FlightAware and its services]


#2

I’ve noticed these, too, and emailed the development team a link to your post. You’ll get a response.


#3

Hi, audioiv. Thanks for your comments!

There are a number of reasons why a flight will sometimes disappear from maps. There is pretty much one reason why the data blocks don’t always show the origin.

Last year we completely overhauled and replaced the code chain that processes all of the radar and flightplan data that’s the backbone of FlightAware’s flight tracking. In this rewrite, among other things we essentially stopped looking at flights based on the aircraft’s tail number (or the airline’s flight number) and instead started looking at them as flightplan IDs (which includes the tail or filght number). The code is very complex and uses extensive heuristics and fuzzy logic to make sense out of data feeds that, including as they do a lot of stuff keyed in in realtime by air traffic controllers, has a lot of discrepancies and idiosyncrasies.

This was important for a ton of reasons that I’m not going to enumerate right now, but one of them is that sometimes there is more than one flight in the air with the same ident at the same time, and the old stuff completely blew it when that happened.

…which brings us to maps. Maps are generated by a pool of machines comprising dozens of processors and over a hundred gigabytes of memory. A key component is a replicated memory-resident database called TrackStream 6. The code chain that makes maps is also quite complex. In particular, TrackStream has not yet been overhauled to be flightplan ID-centric. Consequently it only knows about idents, and it has had some updates to work in a flightplan ID-centric world, but they’re kind of a kludge, like it picks one flightplan for an ident to care about, which is the one that’s in the air at the time. So it doesn’t know the destination until it sees some en route update about the destination for that flight (it had to ignore prior messages about the flightplan because it might have been mapping a previous flight with that ident.) This same confusion is the source of many of the cases where a flight stops being mapped while still in flight. I hope all that makes sense.

We’re in the middle of a major two-phase update to the mapservers. The first is almost complete. In that one we’re upgrading the operating system, security, and all the underlying libraries of the mapservers, plus using a new technique to provide data to the map making layer. You won’t immediately see a big difference, except when viewing an airport the flights to and from that airport will be much more likely to have a datablock because data blocks are prioritized.

In the second update, the work of which is in progress, we’re overhauling TrackStream to be flightplan ID-centric. When that’s done, it’ll solve the no-origin-in-data-blocks problem, solve the two-flights-in-the-air-with-the-same-ident problem, plus make it trivial for us to show the aircraft’s planned route, waypoints, VORs, etc, in maps, and a bunch of other cool stuff.

Of course I wish we could move faster, but we are doing as much as we can with what we have and growing our staff as quickly as we can as well.

Thanks for your patience and thanks for using FlightAware!


#4

Karl,
It sounds incredibly complex. I am in no way dissatisfied with FlightAware, so I want to put that out there that there simply is no competition between FlightAware and any other tracking website.

I will always be loyal to FlightAware, and I’m sure the majority of the visitors here are as well. I appreciate your time to reply to me in such detail.

If I came off as upset or angry, forgive me! I am truly satisfied with the free service (this is very important for critics to understand) that you guys offer.


#5

Totally you did not come off as angry or upset.

We appreciate the feedback and if it wasn’t for all y’all, we wouldn’t get to do these things that we love… get paid to jack with computers and do aviation!