What's a respectable reception range for an indoor setup?
I'm trying to optimize the reception range of my ads-b setup. For now I'm limited to an indoor setup. The best spot I've found so far is the attic, but I'm basically out of cable and trying to add no new hardware, (cables count as hardware right?)
Pi 4 model B
RTL-SDR Realtek RTL2832U
I'm getting roughly 20nm in each direction, but a closer inspection shows that I'm really only getting 10-15nm for traffic under 15k.
I find that the 2d rendering of the furthest observation is not helpful. 3d is much more intuitive.
I have it showing furthest observation by 5k band to see where my low angle interference is. Plus I can take snapshots of each setup so I can compare one against the other. And a few other goodies.
It’s been helpful getting me this far, but clearly at this point my hardware is the limiting factor.
You are correct. Most (not all) windows have a Low-E coating, which is a thin metal film that blocks both UV (heat) and RF (ADSB and others).
Most people will see a LOT better range moving the antenna 2-3 feet either side of the window. Looking throught a wall is almost always better than 'looking' out a metal shield known as a window.
No question, attic (if not using metal foil vapour barrier) or outside is the best mounting location.
20nm is quite poor, but there are some easy things you can try to improve your performance.
Antenna tuned for 1090Mhz will make a huge difference. Telescoping antennas can do well, and there are also guides online on how to make your own tuned antenna from things like tin cans and wire coathangers.
Filter can help if you have a lot of RF noise around-- Broadcast towers and heavy industry nearby, or even just other electronics near your feeder. Low noise amplifier can also make a big difference. You can buy a combined filter/LNA specific for ADS-B use online.
Coax cable type (and length) matters. The RG6 typically used in homes for things like TVs and cable modems doesn't do well with UHF signals like ADS-B. Fancy cables can get expensive, but minimizing your cable length (and number of connections) can make a big difference if you're trying to to spend much money.
Attic is usually the best place for an indoor feeder, but if you have a metal roof, that will kill your performance. If it's normal wood framing and asphalt shingles, I'd bet you can get to at least 100 nm with a tuned antenna and minimizing the cable loss.
Line of Sight calculator.
You can theoretically Rx signals that are coming from a target that is in the LOS. Signals can get reflected from the ionosphere or buildings as well, allowing longer ranges or angles not in the LOS.
Yeah based on the feedback the antenna is the likely culprit. I’m going to try one of those homemade guides tonight, and order a better one if it’s not showing progress
My max range is about 150nm with the cheapest little telescoping antenna that I actually have over 4 feet away from the window. I was pleasantly surprised!
It's one of the low cost antennas that come from the kits. It's a few inches tall, and has a mounting magnet. I'll let you know what kind it is when I crawl back up there later.
I just have it upright on a crossbeam in the attic rn.
I use a similar antenna. I telescoped it to about 70mm (quarter wave at 1090MHz) and put it on a ~12" pizza pan I got from the dollar store. The antenna sits atop a bookcase in my upstairs away from windows. The maximum range I've gotten in ~18 months is 92nm. More commonly, I get signals from 80nm.
And, yes, some energy efficient windows will strongly interfere with the signals. You should see the difference pretty quickly (within an hour or two) if you move the antenna away from the window and compare the results.
The antenna I'm using telescopes. If yours doesn't, that's OK. It will improve the "selectivity" of the antenna a little if you can get it resonant on 1090MHz. Putting something metal, like a pizza pan, under it acts as a [counterpoise](https://en.wikipedia.org/wiki/Counterpoise_(ground_system)) for the antenna, improving its grounding. The 12" measure of the pan is to get it bigger than 70mm in radius. A counterpoise works better if it's at least 1/4 wavelength in radius.
I get around 200nmi max and 50nmi min with my setup. I have a LNA+filter and a mediocre antenna mounted in my loft. My location is definitely a bottleneck because I'm surrounded my tall hills.
What's line of sight like from your home? Lots of trees or buildings blocking the horizon?
ADS-B works best line of sight. In the past 24 hours I picked up an aircraft 247 nm away, but my cheap Amazon 1090 MHz antenna is 13 stories up and right next to a window that doesn't seem to have a coating. I use the FlightAware ProStick Plus connected via a USB extension cable to the Pi 4B to avoid excess noise from the USB 3.0 ports. I got some cheap ferrite beads to try and keep the noise down, too. I have no idea if the extension cable and ferrite beads helped, but they were cheap, and the extension cable helped me get the antenna where I wanted anyways.
UK based in the flat Fens, Got my RPi 4b for Christmas, 360radar.uk own antenna https://www.lowflyingwales.co.uk/store/product/internal-ads-b-antenna/, was loft mounted for first 3 months (18m above sea level), used to get around 100-150nm with around 400-500 messages per second. Moved to roof mounted top of 10ft pole on chimney, now 24m above sea level, improved to 150-250nm with around 1200 messages per Second. Recently bought a NooElec SAWbird+ ADS-B: Premium, Dual-Channel, Cascaded Ultra-Low Noise Amplifier (LNA), turned the software gain from 58 down to 20, now seeing stuff 250-300nm (depending on altitude) with around 2000 messages a second.
Graph shows messages messages per second for last 6 months. Will try and upload range too, but only had it configured with location for a couple of months, max nm is almost 500 (he must have been very high, or a glitch!)
7
u/Teanut 4d ago
What software are you using to create those graphics?