FlightAware Discussions

Planes missing from display

My SkyAware display is incomplete. I base this conclusion on two things: 1. FlightRadar24 displays substantial more planes the SkyAware; and 2. commercial flights over my house or that I can see from house do not display on SkyAware.

I have no idea whether this is a misconfiguration, bug, or feature.

Sounds like a hardware / reception issue.

SkyAware is directly displaying whatever dump1090 hears from the dongle.
if you’re missing ADS-B-equipped aircraft that you expect to be able to see, then the problem is that dump1090 can’t hear those aircraft for whatever reason - perhaps an antenna problem, or you have gain set too high (which tends to affect nearby aircraft more)

What image are you using?

Well that’s what Ibrhought, except when the feed is decided by flightradar24, I can see a lot more planes. It’s the same dump1090 feed.

Would the gain be controlled by piaware or by dump1090?


I hava a similar questions ,

on 21-4 , 3 or 4 F16’s are flying over head, i receive message’s from them , only 1 appears on my radar.

I also had a look at essexradar from @keithma and i see them all

Do i get mlat result back from a other cluster off receivers…?


What do you mean by “when the feed is decided by flightradar24”?

If you’re looking at their online map, that is an aggregated map from many receivers, not only yours.

I think you get back the results if you receiver is actually used to calculate the current position, with a grace period of one minute.

I actually have the opposite problem. I can sometimes ‘see’ a 'plane on my system but it doesn’t show up on any of the sites I feed.

For clarification, I’m talking about 'planes that are being received by one of my receivers and not those marked as MLAT.

I’d love to understand how the aggregators decide what to show and what not to show although I have no doubt that my poor brain wouldn’t cope with the answer.

I don’t see how you’re response answers my question. You wrote that “Skyaware is directly displaying whatever dump1090 hears from the dongle.” But isn’t FR24 doing the same thing? They’re both using the same hardware yet displaying different data.


I just reread your second response. (“decided” was a typo for decoded) You wrote that FR24 aggregates data from other receivers. I infer from that that FA does not and that its map is displaying only data from my receiver. If my understanding is correct, that explains the difference. Thanks.

That was not my response but as stated, if you are looking at the map on flightradar, which is hosted on their servers, you are seeing aggregated data from numerous receivers. If you look at skyaware, you are only seeing the data your receiver is picking up.

The map shown on the flightaware website is also showing aggregated data.

Normally, I see a lot of 'planes on the aggregator sites that I feed that my receiver didn’t ‘see’ although I sometimes see 'planes local to me on my system which don’t show up anywhere else.

Can you explain what you mean by “its map”? There are many possible maps you could be looking at. They display different things. FA certainly does aggregate data; but that’s not what SkyAware is showing.

This is frustrating because I’m obviously using words imprecisely when they have precise meanings in this context. By map, I mean the Skyaware display that I see on my monitor.

I’m trying hard to understand how this works, but it’s not working. I just want to know why there are planes, i.e., commercial flights, I see on the FR24 equivalent of Skyview that don’t appear on Skyview.

And not to further confuse matters, there are planes flying the pattern over my house that don’t appear on Skyview.

There is no FR24 equivalent of SkyView.
And if there is you have to describe how you’re getting at it so we know what you are looking at exactly.

URLs are good for that. (even if they include a local IP, actually that usually makes it quite clear what you are looking at.)

Your local SkyView (more precisely dump1090-fa webinterface, calling it SkyView only confuses matters) will display everything you are receiving.
That is because dump1090-fa is the application using the SDR to receive the aircraft.

I think you already have the answer to this, but just in case:

Skyaware is displaying only the planes picked up by your specific Pi. The web address will be [{YourLocalIP:8080} or {YourLocalIP/dump1090-fa}. So that’s your web browser connecting to a web server on your Pi.

Flightaware.com displays planes aggregated from most/all of the feeders in your area. Your web browser is connecting to Flightaware’s server somewhere out on the internet. Note that on this one, you can zoom out and see planes in areas that are far beyond what your local antenna can ‘see’.

FlightRadar.com also displays planes aggregated from other feeders. Same as flightaware.com.

To summarize, if you are going to a 192.168.x.x address in your browser, or 10.x.x.x, you are looking at your personal map. If you are going to a website url, you are looking at aggregated data.

With regard to the planes flying above your house now showing up - it can be counterintuitive, but if the gain is set too high on your system you will lose planes close to you, while still ‘seeing’ planes that are farther away (with weaker signals). There are a couple of very comprehensive threads on here describing how you can adjust gain to maximize both distant and close-in signals.

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FR24 equivalent=,-149.81/8

Type in your browser this address: www.flightradar24.com/61.2,-149.81/8, is that the same you see when you type the above? Can you see flights that are further away which you local receiver would never pick up?

This is the global FA map

We’re getting closer I think, but we’re not there yet. I’m not comparing apples to oranges, as you seem to imply.

Attached are two screen shots taken mere seconds apart. The source of BOTH shots is data from my 1090 receiver, one is from the Skyaware interface and the other from the FR24 interface. In the FR24 shot, there is a plane on final (to the left of the center of the screen, at the NE tip of Fire Island). That plane doesn’t appear on the Skyaware shot.

One of your screenshots is showing flightradar.com results, while the other is showing directly from your Pi, at The first is aggregate data, the second is direct from your receiver.

Open another tab in your web browser and go to flightaware.com, and center the map on the same area. Now compare all 3.

That extra plane might be MLAT results from other receivers, or could be UAT from other receivers. Could also be below your line of sight, but being picked up by another.

That is the global aggregate feed, not just your local feeder, like skyaware

I’ll try again. So, what I’m getting from Skyaware is a feed from my receiver and nothing else. And what I’m getting from FR24is a. aggregation of feeds from receivers in the area, including mine.

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