Track Log Question?

FlightAware ADS-B Flight Tracking
1

I’m more curious than anything, but I have noticed that FA decides to end the flight early. Below you can see my ADS-B is still picking the aircraft up 200ft lower. Why does the track log do that? Once again, I could care less, it’s more curiosity. This isn’t the first time this has happened.

http://s9.postimg.org/lrpdkbeff/Screen_Shot_2015_04_21_at_5_40_01_PM.jpg

http://s18.postimg.org/omxjh62j9/Screen_Shot_2015_04_21_at_5_40_20_PM.jpg

http://s24.postimg.org/wv69nl36p/Screen_Shot_2015_04_21_at_9_01_30_PM.jpg

http://s15.postimg.org/ko1hae4o7/Screen_Shot_2015_04_21_at_9_02_05_PM.jpg

2

My Radarcape picks up flights on the ground where as my FF box does not report any flights below 700 ft. I think this is inherent to dump1090 and should be configurable. However, on the FA’s server end, they may still be filtering at a minimum threshold.

3

dump1090 (at least dump1090-mutability - I can’t remember the exact set of bugs I fixed versus stock) is fine with low / surface positions (I regularly pick up aircraft landing at Cambridge)