FlightAware Discussions

Missing sqawk in message

Two stations side by side, one receives squawk code from A96B80 (SOO096), one doesn’t. This happened over many message cycles. How does this happen?

I similarly notice that the station missing squawk code also is more likely to miss Ident, although often Ident will show after some cycles. (The other station also misses Ident from time to time.)

Look at the raw messages, then it should be obvious what’s not being received.

Ignoring the 2nd aircraft, look at the message rate of both receivers.
What exactly do you think is a message cycle?

And yeah using view1090-fa --no-interactive or view1090-fa --show-only A96B80 should show you what’s going on as obj said.

In my books, that’s an increment in Msgs column (alternatively, I look at Age reset to 0).

Thanks. I will wait till traffic quiets down so I can easily compare two sites

Have you tried show-only with the hex … ?

You are aware there are lots of different message types.
So a single message will not contain every detail you can think of, far from it.

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Prior knowledge is what this newbie lacks, as evidenced here, there, everywhere :wink:, and this lack is why I am here. So, dump1090, as well as aggregator servers need to combine these messages to make the map work. The “other” receiver may be having difficulty receiving/retrieving some messages. Yes, that make sense. Thanks again. (Although consistently missing one particular type over a period of minutes when airwaves are extremely quiet is still unusual.)

The reception looks like it is particularly crappy :slight_smile:

But really pick a hex and type:

view1090-fa --show-only A96B80

You’ll understand more after.
Ctrl-C and then shift page up to look through it if it’s too fast.

(you have SSH access to the pi right?)