reply to post by ownbestenemy
Your assessment of the tracking is opinion I rather deal in facts. Note that the FAA IS in the business of selling tracking data. You don't get the
fire hose for free. I don't have a recent price on the raw feed, but it isn't free. The internet companies then give the data away in part, but use
all sorts of tricks to recoup the cost of the feed. But if you want to nitpick, it is not pure radar but rather a processed feed. The FAA calls the
service ASDI (Aircraft Situation Display to Industry).
The ASDI data is NOT radar data. Aircraft radar positions are transmitted from ATC radar facilities around the country to the TFM hub site where
they are displayed and/or updated on the ASD display used by FAA air traffic flow managers. Because of communications and data processing loads, only
a subset of the radar positions from each radar facility are updated during each update cycle. Those flights that are not updated are extrapolated
along their last heading, speed, and route until their next update is transmitted. Currently, the radar position for any particular flight is updated
every four (4) minutes.
The reliability of the ASDI data steam is the same as it is for the FAA Air Traffic Control System Command Center (ATCSCC). The data source is the
operational TFM system (with certain data filtered out as mentioned above) and is provided with no time lag. However, it should be noted that the
ASDI data is provided “as is” with no special provisions built in for public release.
That is an old document, so I don't know if the data rate has been increased. I know someone that wanted to start a service similar to flightaware
(which incidentally wasn't the first, but it probably the best known). It required some weird modem, i.e. the feed was not over the internet. And you
had to sign all sorts of papers requiring security since it wasn't delayed.
But surely you recall the "Miracle on the Hudson" flight being tracked on flightaware.
US Airways 1549
Now how exactly did flightaware predict or best-guess a plane landing on a river?
Further, although I don't have the flightaware plot online (perhaps I saved it locally), I was able to determine Janet WWW652 lost an engine just by
looking at the flightaware tracking.
As I have stated more than once, I have ads-b receivers. I know when the internet feed is accurate, and when it isn't. Thus far flightaware is the
only service that at least indicates the source of the tracking. If it is not from ATC, it is a guessimate, otherwise it is pretty accurate.
Now I have seen flightaware make many mistakes. Often when a flight switches from IFR to VFR, flightaware thinks the plane has landed. Again, you need
to look at the track log to see if the altitude makes sense for a landing.
As an aside, there are two ways to prevent your aircraft from being tracked on the internet. One is you file a request with the FAA to be deleted from
the feed. I have FOIAd the list. The list is destroyed every month. The powers that be don't want to be watched. [Hey hey hey, it is only metadata.]
The other way to stay off tracking is to file a request with every internet tracking provider. This is a lot more work, but your blocking request
can't be FOIAd. At one time you had to state that you didn't want to be tracked on the internet for security reasons, and then make up some crap
story about threats. You didn't have to prove you told the same story to the cops or FBI. But in the latest version of the BARR program, you can just
request not to be tracked.
Some people use a different approach.They had their aircraft behind a flight ID.Rush Limbaugh for example was using a flight ID for Gamma. However I
have enough resources that I can track down most people that want to hide from the internet.
My point here is the operation at Groom Lake has a number of ways in which they could stay completely off the internet. They chose not to. Now I
don't know the reasoning behind that decision. Possibly it could be they didn't know they were being tracked for a while. I logged Janets for about
18 months and never published the data until someone else discovered they could be tracked and posted that on the internet. Of course then I had a
pile of good data that I just dumped on the net once that secret was out. So the Janets had a ICAO ID (WWW) and were in the system. Perhaps it was
decided that going dark would attract more attention.
The initial tracking was from Flytecomm. Later a service as Passur came along. They were MLAT but augmented with the FAA feed. They had their own
radar tracking, and it really kicked arse. I caught N105TB showing up to Groom Lake a few times. The service was dropped from LAS, probably due to my