FlightAware Discussions

What on earth does this mean?

Hi nice people,

I have had graphs 1090 running and have absolutely no idea what it is telling me, what is good levels and what is not so good.

I wondered if there was any kind person who would be willing to explain?

image

Hmm, I don’t know. Maybe you should try asking a mechanic, they might know.

The dBFS scale is the signal strength you are receiving. 0dBFS is the maximum signal the dongle can handle. (The FS stands for Full Scale).
The graph is showing you the difference between the strongest and weakest signals you are receiving and the averages. All in all your graph looks pretty good. You have about 20dB dynamic range (difference between the strongest and weakest) which is about what I would expect for a ProStick or similar dongle.

Well with the signal smashed against -1.5 dB it’s really hard to judge dynamic range.
(The digital signal can to an extent be decoded while the high bits are overloaded as they stay 1, full scale)

Thoughts on optimizing gain
Maybe this thread offers you some hints?

A significant part i could say about that graphs would require more info:
Your gain setting / SDR used / coax / antenna used and its location … indoors / outdoors … possible obstructions.
Then it’s good to see the number of aircraft and message rates from the first 3 graphs or so.