Issue with ADS-B

[Wadoadi]

Hi ,
    I have notice what seems to be a small bug. the status page shows zero ADS-B messages but the traffic screen shows ADS-B traffic!
I have seen this on 2 units, one component built and the other from a classic kit.

See attached.

A reboot from the home screen button seems to fix it some times, or sometime just leaving it will go green and start counting and other times not!

I attach screen shots from one of the units

[Keithvinning]

Good spot however
CS is a mode S reception
CSA is an ADSB reception.
Does this help

[Admin]

yes, as Keith says - this is a counter of ADS-B messages not Mode-S or Mode-C

thx
Lee

[Wadoadi]

Oh ok, I (wrongly as it turns out) thought of the red/green status as report on the health of the system parts i.e. that the RTL dongle was working and receiving data...

Thanks for clearing that up.

[Wadoadi]

Now maybe I'm getting hung up on this and you have explained what the counter is and it purpose and it's your system (and a damned good one too) and thus that is all totally fine...

However, from checking various online resources (ICAO ADS-B Guide 1.2, AOPA and even the never wrong Wikipedia ;-) ) all list ADS-B as having various Modes/Classes A, C & S thus any message from any of the modes constitutes the reception of an ADS-B message. Thus should the label of the counter be changed to reflect what it is counting or should the count include these ADS-B message types too?

or have I miss read these references?

 

[Admin]

In fact what this is counting, is a message received from a specific ICAO address AFTER it has been determined that its position is valid.

The data that composes an aircraft position, height, track, speed, squawk etc, is actually split over a number of different packets of data, and it is only the collection/union of packets (tagged by the ICAO code) which gives an overall picture.

So once the overall 'picture' is assembled, that is when we start counting.
Until that point, the data is incomplete, and therefore in effect a bearingless target.

I think you are kind of right in what you are saying, that there are many types of transmission on 1090, but here we are specifically counting packets of data which will contribute to a mapped aircraft appearing on your navigation display.

Thx
Lee