I’m trying to up my range and also understand the metrics available to me. My graphs are attached. One thing that pops out is the 75% one-message tracks which I guess I don’t understand. Does that matter ? Do I need to buy a better antenna ? Tune things ? Something else ?
Also not understanding gain and whether I should touch anything or not. Whatever I have currently is what the software did by default or automagically by itself.
Background - I added the piaware stuff to a pi4 raspi os and basically took all the defaults other than adding tar1090 for the graphs. My gear is on (this) Amazon link and I’m running on the provided antenna with the short pieces attached and each set as close to the 1/4 wavelength length as I can eyeball.
Antenna is sitting next to an open upstairs window and oriented N/S which seems to line up with the coverage I can see if I look at tracks via tar1090 on some days, with things blinking out at reasonable locations as the planes go behind the mountains. My location is about 7 mi. SSW of SeaTac airport below Seattle.
You might be getting interference from nearby cell-phone towers or broadcast AM/FM stations. There is a whole thread on here about determining whether you need a 1090 MHz filter to reduce that interference.Do I Need A Filter?. But rather than going through the 900 or so messages in that thread, it might be easier to just get an LNA with a filter from Amazon and try it.
With the dongle you are using you don’t have any amplification of the weak signals coming in.
The dongle itself is fine but doesn’t have a LNA built in like the Flightaware blue dongle so you might want to improve on that.
I’d advise you to use a LNA as a starter to enhance your recieving capabilities. Also, the stock antenna you are using isn’t the best suited one for ADS-B.
You could improve on that by using either a Flightware antenna or Vinnant Antenna ( I’m sure others will have suggestions too).
@VinceSkahan
There is no need to go through the 900 plus messages of the thread Do I Need A Filter?. Just read the First post, click on one of the 3 options given there, and follow the how-to.
Based on their description of their location in the first post, they are very close to Des Moines, WA, which is right on Puget Sound. It is unlikely that their MSL altitude is greater than 100’ in that area, so while it could definitely be wrong - it probably isn’t wrong by a large amount.
The outline is not bogus in the least and I put in the correct numbers. I’m at 365’ elevation and the offset for the antenna was just a few feet above that, which is also correct. The pattern matches up with the mountains surrounding us in the distance quite well.
Here’s another screen capture with the mountains shown. Notch bottom-right is Mt.Rainier, notches top-right are Glacier Peak and Mount Baker (shown as Summit Crater)
Unfortunately for us, the traffic mostly comes over the mountains from the east, or southeast. So you may get better numbers by aiming for the mountains at the expense of max range. I’m 18 miles NE of SeaTac.
I didn’t get much with an antenna indoors or attic. A Flightaware antenna outdoors (if you can) as high as possible, and even indoors I think a filtered LNA will make a world of difference. I use this popular filtered LNA and the difference is significant.
It comes down to how hard you are willing to try. My antenna is hanging from a tree branch 70 feet up, and I live in a forest. A Blue Flightaware dongle (it has LNA + filter) alone would probably be a decent upgrade option instead. Antenna is really important though.
The blue outline on these maps is Hey Whats That at 40,000 feet. The first map is airplane tracks for past day. You can see the bulk of traffic comes in over the mountains. The red in the 2nd map is actual recent week range plot.
I kinda figured that. Looking at the house and surroundings and what I can reasonably do without being too obtrusive, I have a couple options I guess I can try to mount a FA antenna and have a pi with power nearby.
@VinceSkahan
I started with that same kit from Amazon. Stuck the antenna to a North facing window and got predictable results (planes were in North direction) but mostly limited to about 50 nm range.Then got a 6dBi antenna and reception improved. Then added an LNA and things improved some more. Finally moved the antenna to the attic, and that provided the biggest improvement. Can now see some planes out to 200 nm. Also coverage is more uniform over azimuth.
I was surprised at how much improvement I got from the attic location. It’s only about 7 ft additional height, because the attic only has 5 ft clearance at best. I figured that being closer to the concrete tile roof (Southern Calif roof style) would be a big loss, since concrete has lots of attenuation at 1090 MHz. However it might be that since the antenna is now slightly above the attic mounted furnaces – that provides a gain. Anyway, this probably provides the best reception for an indoor antenna. I can’t put up an outside antenna because HOA rules. (Well, we will see).
your receiption is really weak.
First most important thing is…line of sight…
You need to have a clear sky to receive the signal no obstacle please.
Because of the sdr my favourite is the airspy
So if you think you can not use a rod antenna because of you HOA rules …but you think this tiny antenna can be used…and if you want to feed your data in to what ever …and it is your hobby …and you are enthusiast…ok…
shoot me an PM with your adress
I have an engineering sample here …you will get it for free
by the way this tiny antenna has a little bit directivity…with very long range and 10 dBi high gain. It will produce also I will say a higher “resolution” then standard rod antennas.
minor update - I moved my rig up to a NE-facing second floor windowsill and am seeing about 80 nm with the window open but the metal screen in. Highest distance lines up of course with line of sight.
The big notch in the map to the SE is Mt.Rainier (14,000 feet) about 42 statute miles away, but it sure looks nice on a sunny day
I guess your post was a response to me.
Anyway, I already ordered and will try the filtered LNA you referenced to see if that improves reception. However, I don’t think I actually have much RF interference since I’m in a radio dead zone. We have problems with cell-phone service here, so probably don’t have interference from cell-phone base stations!
Right now I’m just using the unfiltered Nooelec LNA.
Regarding the patch antenna – thanks for your offer, but I’m going to look at some other options first. I might come back to it later.
And distances went way up when I moved things to a 2nd floor window on July-3rd. Window is open but the screen is in of course. I figured the solar-tinted double-pane window would be bad mojo for reception.
I put the filter into place only 24 hours ago so I can’t see any great change as a result there, but it ‘is’ just the right diameter so just sitting there attached to the pi4 everything is nice and level with no stress on the dongle USB connection, so there’s that I guess. Max distance now ‘seems’ to have gone up maybe even 20 nm but I’ll need to get a whole week of flights to see if there’s any conclusions that are more than just eyeballing things.
