Sorry if this has been asked before but I have a Raspberry Pi 3B Plus with the adsb Exchange image on an SD card that I’m using as a feeder. So my question is on the adsb Exchange app I can see a helicopter and planes but on my feeder I cannot see the helicopter even when it’s close to my area only the planes but I can see both when looking at the adsb exchange app has anyone ever had this problem or is is it a sitting that I’m missing ? First picture is my feeder second picture is the adsb exchange app
hello. That bottom app is not created by us. We recommend you use our website globe.adsbexchange.com directly from your mobile browser. thank you.
okay in this picture on the left is my feeder on the right is global. Adsbexchange.com how exactly is it any different other than what the app showes at the bottom of the screen on the picture that I showed in the original post I’m not seeing helicopters when they’re close to my area on my feeder but yet on the website globe.adsbexchange.com I can see the helicopters both of these are running at the exact same time. My question was why am I not seeing them on my feeder but I’m seeing it on the website running through the same browser same internet is there some kind of setting that I have missed?
The globe is an aggregation of many receivers in the area whereas yours is just what your feeder is picking up. There could be many reasons for not picking up aircraft including blockage on the line of sight at your location, interference from other RF signals near your receiver, the antennas you are using, etc.
Can you share your feeder name (and Feed UID via a Direct Message) or enter your feeder name in the ADS-B Exchange - Leaderboard and tell us what your stats look like. You can also send us details when clicking on “ADSBx Anywhere Stats” from this page ADSBexchange Anywhere
Yes I can share my feeder name and my ID on direct message how do I direct message you with this
What SDR are you using? What antenna, and where is the antenna installed (indoors?)
Unless you’re severely limited by terrain, something is wrong with your receiver. Could you post screenshots of http://adsbexchange.local/graphs1090/?timeframe=48h
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Yeah, something’s not right there. Check coax connections? You probably get better results (or no worse) with the rubber-duckie antenna right on the SDR!
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I would agree there is something off here. Judging by your name you should have at least some RF knowledge. I would try the rubber duck in a window as a comparison against your outside antenna. I find even with a bad setup High altitude aircraft are generally pretty easy to see and track. Not sure how your gain got so high but I believe your at a good starting point for getting set up. Not sure how high the terrain is around you as it may cause some reduced coverage but aircraft over 30K ft within reason should be visible on your local tracker unless your surrounded by pretty high terrain relative to your antennas position. If the included Antenna on the SDR gets better reception you have a Feedline or Antenna issue, If not you may have a bad amp in the SDR. also if you only have the blue SDR perhaps the aircraft you are hoping to see are using 978 UAT or ADSB-R. you can see that by hovering your mouse over the aircraft. Some Aircraft that do not go above 17,999 ft use 978 instead of 1090.
It’s the SNR that’s leading me to believe that it’s a hardware issue (likely antenna system, but could be a defective SDR). If it was terrain, the noise level would be low(er) and the peak signals high (overhead/nearby aircraft).
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I have upgraded The coaxial cable and upgrade has enhanced the feeder’s performance, which has operated optimally for 24 hours. Signal reception has improved significantly, enabling detection of signals from 150 miles away and displaying approximately 30 tracks on the screen, a notable increase from the 12-15 tracks detected with the previous cable. Although helicopter detection remains challenging, the upgrade has been successful overall. We appreciate your assistance. Currently, another feeder is operational, and as of this writing, it is tracking 41 tracks with the new coax, resulting in a substantial improvement with both feeders.
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Glad that helped. I’ve been experimenting with antennas over here. I have had great success with the coaxial collinear antenna on 1090mhz. 978 on the other hand has been driving me nuts. I need to get another pi up and running to see if it’s interference or something else because i built another coco antenna cut for 978 and had worse coverage than a mag mount with junk cable several feet lower. As for your helicopter issue I think it maybe two fold. They generally fly low to terrain and you have terrain. I would compare it to live global feed vs yours and see that they are definitely using ADSB and not ADSB-R or UAT. If they are using ADSB then you may try to do a terrain profile online between your location and their location.