Urban PiAware tracking planes ~35miles out, ~40k high. Any better?

I’ve got a piaware running on a balcony in downtown Seattle that can pick up planes overhead up to ~40k feet or as far out as ~35miles (imperial). Output online: https://flightaware.com/adsb/stats/user/digittante.

Given this environment and the setup (below), are there options we might explore to expand the detection range?


Our PiAware setup:

  • RaspberryPi Model 2 B+
  • Edimax Wifi dongle plugged into the pi’s onboard USB
  • Pro Stick Plus dongle (PSP)
  • 1090Mhz Antenna MCX (link)
  • 3.5a PSU on the pi
  • Piaware via the Debian package add-on
  • No other devices, attached, no other apps or programs in use besides SSH

Place the antenna over a metallic surface such as lid of a large can or food can.



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Mmmm, butter cookies! Thx, will try that.


Yes, do try butter cookies, they taste good :smile:



in downtown SEA, I would try first gain setting 19.7 or 20.7.
you can also try the ‘optimize-gain’ utilities, found in this site
and find what is best for you.

PS. in YUL I currently use similar setup with gain 19.7 - no filter - cantena

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Correct link (Post #4, not #12)

By the way, your range curve 200+ nm with Cantenna and gain 20.7 is amazing.

thanks for the correction

actually I use 19.7 now (last 3 days) site 58986.
if you compare with stats from site 59070 (same balcony and gear but dump1090-mutability)
with mutability I get more range - over 300nm - but less positions/aircraft.
is definitely an improvement. though for cantena I use a tuna-can. (not tight for my fingers as the coke).
I think that prostick pro is a marvel.

it could be better with a filter or FF but can’t afford it.

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Given your location in an urban environment, I suggest you install the external filter from FlightAware. This will likely improve your reception. Generally speaking, even in a second story window in an urban environment, I would expect you to be able to receive more messages than your stats are showing currently. The best sites can receive aircraft 250+ miles away. If you are in a high floor of a high-rise building you may do even better.

To improve range in general, you need to elevate the antenna as high as possible, minimizing any obstructions between the antenna and the aircraft you are trying to receive. Trees, buildings, mountains, etc. will all block weak/distant signals. You can also try installing a gain antenna such as the one made by FlightAware or others.

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hi Eric

like I wrote, I would have preferred FF / FA antenna and filter but I can not afford it .
my position balcony / NE corner building 3d floor 167’ (gps) and 0.3 nm from the ILS path for rwy 24R.
so half my horizon is blocked by the very building from 060° to 240°. also unable to put antenna on building roof.

rgds / Evangel

ED1 that setting display aircraft as far as 250nm+ and MLAT 300nm+

Thank you. I’ll play w/ gain next and report back if there are noticeable changes.

You can determine what interfering signals are received by you antenna. This wont cost you anything except less than one hour of your free time. Please visit the thread below to see the detailed instructions.

Do I Need A Filter?

Please have a look here, if not yet seen:

TWEAK-3: Gain Optimization Scripts

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hi abcd
I run 4 tests different gains 5 min each. I think it shows interference between 800-900 MHz.
dont know how to enlarge the images, but here it is.

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@evangelyul: The scans show that you have strong cell signal around 880-890 MHz.
A filter will most likely improve ads-b reception.


This is how I have done it:
Opened the image in MS Paint > Clicked “Select” on menu > Selected area 850 Mhz to 940 MHz > Clicked Crop on menu > Clicked “File” on menu > Clicked “Save As” > Saved with a different name than original image (using same name as original image will replace original image by cropped image, and original will be lost).

gain 19.7

gain 29.7

gain 40.2

gain 49.6


thanks abcd

and with increased gain the more the interference right ?

Yes, lower the gain lower the interfering signal AND lower the ads-b signal.
What gain setting you are using?
If using “max” or 49.6, change to somewhat lower like 45, then 40.
With each setting observe reception to find if these lowered gain settings give any improvement in ads-b reception.

@ abcd
gain setting now 33.8 on dump1090-mutability.
(as suggested by optgain.py) :grinning:

49.6 23404 3907 79
48.0 25481 4193 74
44.5 26318 4678 78
43.9 26879 4432 71
42.1 27050 4613 76

40.2 26867 4519 79

38.6 27568 4158 72

33.8 28050 4063 71

25.4 25170 4089 66
20.7 23039 3479 49
19.7 19368 3337 50
18.7 19655 3449 46

what is interesting is when i use the piaware SD 3.5.3 and dump1090-fa gain 19.7 as seen in my posts above have equal or even better results. the reason i prefer dump1090-mutability though is the charts and the map choice of IFR, WAC, TAC etc.


Wow! The performance graphs show that your maximum range is 500nm, and average is 280nm. Fantastic.


well, as per Obj, for some reason the decoder registers MLAT-only FA server returns in excess of 360.
for this I set dump1090-mutability max range 500nm !!
Modesmixer and VRS do very good displaying these.


with polar limit at 360nm.

but if registered, it counts right ? :wink:

Reporting with a non-technical update:

I’ve replaced a 6-ft telescoping antenna with the original back to the original/recommended one and have seen tracking results improve both in # of planes and the max-distance.

For example, from my downtown Seattle location, my station tracked this flight to Hawaii up to 113 miles away over the Olympic Peninsula and mountain range.

I’ll call that good.

Thanks to everyone for the ideas to investigate further.