ADSB 'Plus'

[n5pwp]

I've been monitoring ADSB for awhile and I've seen these 'extra' blips to the side of the usual 1.090GHz. I'm running SDRUno to monitor using their ADSB plugin. Apparently it locks the filter bandwidth down. Usually I can stretch that window out. Also, if I select a different filter in the RX Controller window it doesn't make it any wider. Are those ADSB pulses for A/C also? Is there a way to monitor them? I guess drop the ADSB Plugin and just tune to that frequency and see if Dump1090 decodes it?
Mike

 

[BM82557]

Aircraft slightly off freq

 

[n5pwp]

That sounds plausible. I notice that they seem to be 100KHz off. (ex: 1090100, 1090200). I tried playing with the gain thinking maybe its an artifact of the gain being too high. If I lower it then it goes away. Would doppler be an explanation for A/C that are a distance away and they will slowly merge with the main signal as they get closer? I've seen doppler affect LEO sats and they travel across the spectrum.
Mike

 

[AB5ID]

I'm not sure about ADSB but DME interrogations that are 200kHz off still have to be counted as valid.