Hi All – My first-time post on this forum! Hope all are well, had a merry Xmas as possible, and wishing you a much happier 2021! Father Christmas was very kind to me this year and gave me my very first Raspberry Pi (the CanaKit RPi 4 Starter Kit, with 32Gb SD, 4Gb RAM, case, etc), a FlightAware Pro Stick Plus, a FlightAware ADS-B Mode S Filter for 1090 MHz (which I am suspecting I don’t need now I have read the FA Pro Plus dongle does filtering?!), and an Internal/External ADS-B Antenna. I have no experience in these matters, but I am a fast learner and can Google (which is a dangerous thing!). I want to add a feeder to a flight tracker service and have narrowed down my preferred candidates to 360Radar and ADS-B Exchange. I live approximately mid-way between RAF Mildenhall and RAF Wattisham, and consequently one of my main criteria is tracking/seeing military aircraft. Please may I ask a few questions to help point me in the right direction. 1. I appreciate this being an ADSBx forum, the answers may be a little one-sided(!), but what experiences have people had with both (360Radar vs ADSBx) and what would you recommend? What are the pro’s and con’s I should know about? 2. I have a good location in mind for the antenna, but running the cables is (not) going to be a fun challenge! How significant is it to have your Raspberry Pi ethernet connected rather than rely on WiFi? 3. And finally (for now), any views on whether I should return (to Santa) that FlightAware ADS-B Mode S Filter for 1090 MHz (seeing as I have the AD Pro Plus stick)? I don’t live anywhere near any mobile phone masts, but then again, I don’t yet have enough experience to know how sensitive this antenna is?! Many thanks in advance of any advice people can offer! Alan
I'm biased and my preference is clear but you don't have to restrict your data feed to one party. WiFi is fine. I wouldn't return it, the FA Pro+ Stick can have issues with interference from things you wouldn't expect to be an issue as the LNA is before the filter and can get overloaded. Here go this route, all feeding to anyone is optional: https://github.com/wiedehopf/adsb-wiki/wiki/Raspbian-Lite:-ADS-B-receiver You can set it up with the antenna hanging by a string in a window. As long as you don't replace the decoder and just use the existing data, the feed to 360 radar shouldn't disrupt the setup as described in the link. We at adsbexchange have put our mlat-client into a virtualenv so there is no package conflict with other services using an imcompatible version of the mlat-client and still calling the debian package mlat-client. So that part shouldn't be an issue.
Hi again. Apologies for the radio silence (no pun intended). I was missing a connector for the antenna (now resolved) and, sadly, we have a family member in hospital (not resolved). So had some ongoing higher priorities. Your link above was a life-saver. Thank you. Pretty sure I have the basics set up okay now, but would welcome some more advice. As I am a complete newbie, let me run through what I have done and where I still see some challenges (Please keep in mind that if I use some technical lingo it's probably because I've googled it somewhere and doesn't necessarily mean I fully understand it!): 1. Starting point: CanaKit RPi 4 Starter Kit, with 32Gb SD, 4Gb RAM, case, etc), a FlightAware Pro Stick Plus, an Internal/External ADS-B Antenna. I also have a FlightAware ADS-B Mode S Filter for 1090 MHz. 2. Following your guidance, I: a) Used the Raspberry Pi Imager to build a Raspberry Pi Lite SD (using a Windows 10 laptop) b) Modified the Raspberry Pi Lite for a Raspberry Pi Headless install (wpa_supplicant.conf and ssh files) c) Installed Putty on my Windows 10 laptop d) Transferred the SD, fired up the RPi, Ping'd the RPi to get its IP address, used Putty to log on to the RPI, changed its password, did a sudo update and upgrade e) I then took your advice and run the "automatic installation for readsb" and then the "Tar1090 web interface" install f) And finally, I used sudo readsb-set-location to set my location. 3. The good news is, when I do << my IP address >>/tar1090 in my Windows 10 laptop Chrome browser, I get the map and some aircraft shown. The somewhat disappointing news is I don't see many aircraft compared to the global ADSB-Exchange Tar1090 map. I notice my setup can see some very high aircraft quite a long way away, but relatively close (10 miles) low level (3,000 feet) aircraft can't be seen (but are visible on ADSBX). The situation is not helped by several factors: a) Pandemic/Lockdown means the skies are relatively quiet (I live mid-Suffolk, UK, not far from Stansted and RAF Mildenhall/Lakenheath - So not normally quiet skies) b) There's a howling gale outside, which must be impacting the number of flights c) The antenna is in door, beside a window, but on ground level, with the house most probably shielding many signals. 4. I plan to try various things to improve results: a) Currently using LAN ethernet connection to the RPI. But I shall go wireless and try relocating the antenna in various places, including upstairs and raised areas outside, away from the house b) Also try with and without the FlightAware ADS-B Mode S Filter for 1090 MHz to see if that helps. Questions: 1. Have I missed anything in the setup described above? For instance, I haven't yet tried your "automatic gain optimization" script, as I figured this would be best run when the antenna location is settled? There's mention of an "Update" and "Configuration" on your Tar1090 GIT page, but these sound optional (and tbh, I wasn't sure I fully understood them). There's also mention of "configuring the web interface" but I wasn't sure where I would do this and what it does. Could any of these be significant? Please still advise if you would recommend any steps, even if not related to improving my reception issues. 2. How can I tell what the receiving quality is like? If I select an aircraft (in the Tar1090 web page) I can see a SIGNAL section, which presumably would tell me what the signal strength is like for a particular aircraft. To be honest, I don't know how to read the various figures it lists. But if I do this, and maybe compare the same with the global ADSBX Tar, can I make any assessment of signal quality? Ultimately, it would be helpful to know how to do this so I could test various antenna locations and determine the best position. Obviously my ultimate aim is to feed by receiver in to ADSBX. But for now, and hopefully with your help, I would like to improve the results I am seeing first. Any guidance would be much appreciated. Alan
That's literally running one script so that's not hard at all, no need to wait until later You can run it ... doesn't hurt. This might be some reading: https://github.com/wiedehopf/adsb-wiki/wiki/Optimizing-gain Go to the tar1090 page and look at the range outline and pTracks section: https://github.com/wiedehopf/tar1090#heywhatsthatcom-range-outline Also install graphs1090. You'll piece the info together. Important thing to remember: 1090 MHz is mostly line of sight so yes your house and other houses or obstacles will mostly block the signal. You haven't really specified which antenna you're using and how you placed it as well as the connection to the SDR. In terms of reception that's a critical part.
Welshwood.. I have played around with several antennas and the DUAL 978/1090 MHz antenna sold by ADSBxchange is definitely a better antenna (sold out right now - https://store.adsbexchange.com/products/5-5dbi-1090-978-antenna). I went from 60 aircraft to over 200 daily and reaching out to 178 nautical miles and almost to the 200 nm ring. I live in Florida (USA) and it's relatively flat and I have the antenna about 2 feet over the roof line. Pretty good line of sight in all directions with the exception of the south (neighbor's big oak tree). Since you said you have it up and running, you can get another dongle and split sma cable with a pigtail (the end you screw into your dongle now). Here's a link to the pigtail - https://www.amazon.com/gp/product/B07STYNB6V/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1. The additional dongle will allow you to pull in data coming over 978 MHz. You will need to enable it in the configuration file by telling readsb which "device" will pull 1090MHz and which device will pull 978 MHz. Run sudo rtl_test from the command line and it will show you which device number is assigned to which dongle. The -d switch is then used in the configuration file such as -d 0 or -d 1 - where 0 or 1 is the device. Search the forum topics for examples/instructions or even github. Broadcast frequency 1090 MHz is mandated globally and in US Class A Airspace, and the ES part (Extended Squitter – mode S required for implementation) is a message or series of messages. Broadcast frequency 978 MHz UAT (Universal Access Transceiver) is for use below 18,000 MSL.
Thx FlyKMCO. Sounds like you have a great line of sight! I'm pretty sure I am right in saying 978 MHz is unique to the USA - so wouldn't be relevant for me here in the UK. But I am sure someone will correct me if I am wrong. Wiedehopf - Thanks also for your reply. I went back to your very first suggested link (above) and installed the autogain script (for the readsb). Looks very clever . I also did your suggested heywhatsthat range outline... wow, that's brilliant! (One of my other hobbies is Astronomy, so this site looks useful for that too!). I now have the tar1090 using my panorama range profile: Looks like I can (theoretically) see beyond 200 miles. But obviously there will be local obstacles... so my search for that perfect spot goes on! I also did the graphs1090 install, which looks very good - although I have to admit I have a lot to learn there on how to interpret this! I suspect these will be very useful in trying to evaluate the best location for the antenna over time. Do you have any advice or good reading on how to read these graphs? I hope to find time to play around with various antenna locations over the next week or so. At the moment I am still seeing a pitiful number of aircraft, but I'm not too surprised (or disappointed) because the antenna is still indoor (upstairs windows positions don't seem to help). Outdoors will be the real test, I am sure. You asked which antenna I have. I can't work out how to insert the link without the forum site thinking I'm posting a spam! But its the only antenna on the home page of lowflyingwales (co uk) website. The connection to the SDR is via the supplied 1.5 m cable, and uses an SMA connector (supplied) direct to the FlightAware Pro Stick Plus. I haven't yet started to try and use the FlightAware ADS-B Mode S Filter yet - I figure that might be "fine tuning" once I have worked out a good location. My biggest issue, I suspect, is getting the gain right. As mentioned, I have (only just) started using the autogain script, but I seem to never see anything at low altitudes. Had 2 Chinooks fly very low over the house last night at around 2000 feet (very close formation, very dark and with no lights on! Ground thumpingly very exciting!). ADBSX could see one of them, but my tar1090 couldn't. I seen you mention the sudo readsb-gain command (haven't tried it yet) in one of your posts, but I would be shooting in the dark at what value to go for. Any advice?
Here's a view of what I see: Left ADSBx, Right my tar1090. As you can see, it's not seeing some of the closer, but lower aircraft. My preference would be to capture all aircraft within, say, a 30 mile radius, rather than try and push things for distance.
Well that's why i linked the page about optimizing gain. If you don't care about far away targets ... FA Pro+ ... try a gain of 34. If you have the filter, use it. That's for aircraft at 40000 ft if you're referring to the blue outline in tar1090. For 5000 ft ... it'll be well approximately 1/8th as in 5000 / 40000 (a bit more but it's a good enough approximation) Also the 200 mile won't be all directions or is it. And yes without the antenna on the roof of the house or at least in the attic .. reception is usually limited. Attic isn't as good as on the roof but can be acceptable.
I've tried two locations outside now, and can't say I could see any significant improvement from when indoors. Mind you, the locations weren't as high as on the main roof. One was on a lower floor roof (basically, an extension to the main house - so the main house was still a bit of a blocker). This is by far the easiest location to get power to. The other location I had in mind is on the top of an external summer house building - well away from the main house but still near a WiFa AP, and its slightly higher than the first location. Getting the antenna on the main house roof may be a little challenging. I'd have to buy some cable extension and make sure joins to the 1.5m cable are very secure and water tight. Also mounting space on the roof is very limited. It would have to be either next to, or on top of the same pole as the digital terrestrial TV aerial. I'd be interested in any thoughts as to whether this would be a bad idea - maybe there would be interreference from the TV aerial, or vice versa to the 1090 antenna? The attic idea is a possibility - I haven't tried that yet. But I'm reluctant to start drilling holes in walls for cable and power if the end result isn't going to be much different from some of my preferred "lower level" option 1. I also tried sudo readsb-gain 34 but again, didn't see any improvement. ADSBx shows lower altitude but relatively close aircraft, whilst my tar1090 doesn't show them. Maybe I should settle on a "test" location where I can leave it up and running for a few days and let the "automatic gain optimization" script have a chance to do its magic? One other final thought - I haven't started the ADSBx feed because my setup isn't up and running 24/7 yet - and, of course, I keep experimenting on locations! But if I do, would that help you to help me (!) in working out what gain I should be using (or any other settings) to see these lower/nearer aircraft? Really appreciate all the help you have been offering. Thank you for your patience! Alan
That's no reason to not enable the feed .... doesn't matter if it's not on all the time. If you install not only the feed but also https://github.com/adsbxchange/adsbexchange-stats then you can get a link to a personal feed map that you could link here. But i doubt it would give much insight. Can't you just follow the instructions in this link? https://github.com/wiedehopf/adsb-wiki/wiki/Optimizing-gain The autogain doesn't do anything else. Anyhow you an also install the autogain and run it manually every 10 mins or so. Really most likely it's just obstructions ..... just go where the antenna is ... if you can't see the horizon ... you won't have good reception ... (ADS-B will go through clouds and maybe 2 trees but not a whole fores) Anyhow you can imagine that your locations are very suboptimal from the view of the horizon for those places. Aircraft flying 2000 ft ... you can't see very far unless you have a really good view of the horizon.
Done: ADSBx feed enabled (Welshwood-Suffolk-UK) and and stats installed. I'll keep running the autogain to see if things improve. Not sure I follow? I was saying I couldn't see an aircraft that was 2000 ft directly above me, so I don't understand why I would need a really good view of the horizon to see it? Apologies - I probably simply don't understand - Or maybe it will improve with more autogains and time?
Well that's indeed curious ... if it's only MLAT then you couldn't have seen a position without feeding .... as only that will give you the mlat results back. But you could still have seen it in the list on the right even without position. And yes for aircraft low and very close gain can easily be too much. As such autogain can be suboptimal as you might want an even lower percentage.
I think you might be on to something there regarding MLAT and that overhead aircraft not being seen. It was the military - so not necessarily using ADS-B. It was two chinooks, very close formation, directly overhead (about 2,000 feet). Only one was showing on ADSBx global map - but neither were visible on my tar1090 map. Maybe it was MLAT? I hadn't appreciated how MLAT works (i.e. needing to be via multiple feeds). I've done some Googling and have a slightly better understanding of MLAT now. I wasn't "feeding" at the time, so that may explain it. I'll keep an eye out for that next time. And thx for the top-tip about checking in the list on the right (I'm still finding my way around!) Is there a sudo command that will tell me what the current gain is? And (probably a silly question, but just to make sure) if the gain is currently too much for low/close aircraft then presumably I should try something like sudo readsb-gain <<some number lower than the current one>> ?
Yes. There is a section on the readsb install about changing the config that's where the gain is configured (it's modified by the helper). Config file is /etc/default/readsb you'll find the current gain in there. You can also check the log for readsb as described on the github page.
Things seem to be settling down nicely now (Thanks for all your help ). The antenna is now installed in the attic. Perhaps not the most ideal location, but things definitely seem to be working reasonably well now. I had previously followed your suggestion on https://github.com/wiedehopf/tar1090#heywhatsthatcom-range-outline and this did give me the really fancy blue outline of aircraft visibility @ 40,000 ft in tar1090. In experimenting with different antenna locations, I have now rerun and loaded different heywhatsthatcom location IDs for my new panorama URL, but the blue outline is no longer on my tar1090. Any suggestions on how I could get that back?
Well you did it wrong at some point. Do it again but correctly as the instructions say. Also you might be confusing your local tar1090 and the online feed map.
