Hi, I'm wondering if there are any settings to optimize the feeding to adsbexchange... I'm feeding the same antenna signal into an FR24 and a Planefinder receiver as well as my rtl-sdr v3 and Rasperry Pi unit running ADSBx Custom Pi Image using an antenna splitter. The FR24 and Planefinder units when they start tracking a plane at their furthest range it takes the Pi unit 500-2000 messages (compared to the FR24/PF) before the Pi starts tracking it and I see it on the local tar1090 page.... I've optimized the gain settings for the lowest noise floor, but are there any other settings to make the Pi track new planes faster? I'm using the stock adsbx-env: I've also set up ntpd which I think is optimal (I've dabbled quite a bit with ntpd before so it should be ok). Are the FR24/PF units frontends so much better than the rtl-sdr ones? Appreciate any tips to try. Cheers //Greg.
That is usually not the way to optimize ADS-B. https://github.com/wiedehopf/adsb-s...-gain-optimization-for-readsb-and-dump1090-fa https://github.com/wiedehopf/adsb-wiki/wiki/Optimizing-gain Some hints on my experience with gain. The rtl-sdr v3 as a standalone isn't a really good ADS-B receiver that's why they produce this thing: https://www.rtl-sdr.com/product/rtl-sdr-blog-ads-b-triple-filtered-lna-bias-tee-powered/ This thing works well as well: https://store.uputronics.com/index.php?route=product/product&product_id=50 If you really want to go all out you can get an airspy mini (and one of the filtered LNAs above, airspy mini alone won't cut it, not sensitive enough). The FA ProStick+ is also not bad, but the standalone filtered LNAs with an rtl-sdr v3 or a nesdr stick generally perform better. The discord is also a good place if you have questions or want do discuss SDR stuff: https://discord.com/invite/n9dGbkTtZm Anyhow the FR24 / planefinder units are significantly more expensive than an SDR, they are variants on the jetvision radarcape with some customizations. But with an LNA / filter you can usually get at least somewhat close in performance. On a more general note, for a network of receivers like adsbexchange it's actually not super important to get every bit of range as for low flying planes the range will be restricted by terrain / curvature of the earth anyhow. Signal strength is not so critical for that usually.
I did just that optimization procedure for the best SNR ratio, it also happened to be the lowest noise floor. Also the antenna already has an LNA, and I'm not looking to spend any more money on it, I'm not looking to increase the overall range or anything, the question I had was if there's some setting to make dump1090 lock on faster. As I'm feeding exatcly the same signal into all units but it takes 500-2000 more messages compared to the FR24/PF units to show up on the Pi's local screen... Cheers
It shouldn't take that many messages to show a position. You mean you receive 500 messages on the pi before it shows a position? That seems strange. Range and aircraft being picked up only when they are closer is the same thing. Both receivers you compare to have a combination of filter ->LNA -> filter -> LNA internally. Or something along those lines. Also splitting the signal three ways attenuates the signal a lot. You by any chance have a Feeder map link from https://www.adsbexchange.com/myip you can send me in a private message?
