Is that your job or is it a hobby? I’d love to see some of your 360 degree imagery if it’s publicly available?
I switched on MLAT around 9am this morning and so far there are 78 MLAT aircraft reported, not far off 10% of the total. I forgot to switch on traffic flow monitoring to see how much data MLAT was using on that specific device but I think it’s in the 20-40 Kbit/s range. The “other” craft entry has sharply dropped, presumably converted to the MLAT category.
Looks to be a few more sunny days ahead and perhaps some more nice sunrises to come!
It’s just a hobby but I’ve not done any more in the last year and a half having exhausted the areas of interest and the sad demise of the company that made the stitching software (Kolor) with some unique abilities that enabled me to work some magic with the skies.
All my 360s are at Roundme - create Stock 360 VR panoramic pictures virtual tour online - hope you enjoy the views!
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Your setup works really well! I see an immediate upgrade I can carry out and that is to use some string to hang it up. Gaffer tape slowly lets go over time and I’m half expecting to hear something go bump in the night!
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Last year summer my peak was at 156, but lower message rate because it was mounted indoor. For this year i am expect a bit higher performance, but it’s limited based on the area.
Looking jealously at your installation 
Oh yes, absolutely stunning!
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Glad you liked them. At least the 1090 aerial view is not so weather dependent unlike my other aerial views somewhat further up the EM spectrum 
The gaffer taped FA aerial continues to amaze me, consistently seeing quite a few aircraft beyond 250NM. Admittedly they need to be at quite a high altitude!
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My antennas are a home made Coaxial Colinear encapsulated in PVC for 1090 MHz, and the FlightAware 978 MHz antenna. Also on the same mast is an Antennacraft Model ST2 Scanner antenna.
I was very happy with my reception when I first moved the 1090 MHz antenna up to the 2nd floor chimney (from indoors). Huge difference.
Both Dongles are running on the same Raspberry Pi.
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Your UAT reception appears to be very good. Are there a lot of GA aircraft around your site?
There are three flight training schools I see aircraft from on UAT: Florida Tech, Flight Safety International, and Embry-Riddle. Most of the UAT traffic seems to be GA, and mostly training flights. It’s very dependent on the weather. In bad weather there is no traffic.
Just added the Uputronics Pre-amp/1090 filter to my setup. It’s only been running with the pre-amp for about 5 minutes, but I’m already seeing improved performance. Not necessarily in range yet, but definitely in number of aircraft reported. As I expected, I had to significantly reduce receiver gain to a more appropriate level (48.0 right now).
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The Uputronics does a great job of fitering so you may find a bit of an improvement by taking out the FlightAware filter, which may have now become redundant.
I have the same setup indoors by a window, and I also had my gain up in the high 40s. I’ve seen an improvement by reducing it to 32.8, which I homed in on by using graphs1090 ADS-B Signal Level to find the gain which gave around -3 dBFS to -25 dBFS. It maximised the positions and aircraft seen.
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I set mine to 34 hoping to reduce the number of >-3bB messages.
You can see right at the end where I dropped the gain from ~44 to 34.
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At which level where they before?
I don’t remember exactly. The only gain changes I made before the addition of the preamp were made using wiedehopf’s auto gain script, but it seems to increase the gain too high (% of >-3bB messages is really high).
Any input you can give me on which parameters to look for in terms of proper gain adjustment are appreciated!
What seems to work well is to adjust the gain so that the lower level on the graph drops without pulling down the upper level. This seems to result in a spread around -3 dBFS (the ‘loudest’ you want your strongest messages to be) and -25 to -30 ish dBFS (not far off merging into background noise). The value of gain which achieves that is different from site to site as it depends on the kit, antenna, preamps, how it’s sited, etc.
One way to find your value is drop it a notch or two each day and see how the graph looks and how your numbers pan out. Watch the lower value drop each time, and take note if the upper value starts to drop too. Eventually, after a few days of doing this, you’ll find the sweet spot. Note that during quiet periods at night the upper and lower levels jump around a lot so you just want the busy day time traffic.
From that sweet spot, if you increase the gain you’re making your strongest messages ‘louder’ (increasing numbers of stronger than -3 dBFS messages) which doesn’t help them but can mask fainter signals. And if you lower the gain, you just make all your messages a bit weaker without gaining any fainter signals, and possibly losing some.
It’s not an exact science but that approach seems to be good at finding a near optimum gain.
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Thanks for the detailed information! For the last 24 hours I’ve been at a gain setting of 34 and I believe my signal level graph is looking as it should. As you suggested, I’m going to lower it by 2 at the same time every day and continue to monitor the results.
It’ll be interesting to see how it works out for you and how your numbers are affected once you obtain that maximum signal spread on the graph. To be clear on the numbers (since people talk about “higher” or “stronger” and it’s not always clear since the values are negative):
strongest signals <–– -3 dBFS ––––––– -25 dBFS ––> weakest signals ––> background noise
Raising the dongle’s gain is moving it towards 50. Lowering the gain is moving it towards 0.
Valid values for the Pro Stick Plus gain:
0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6 max
If you use a non-valid value (eg 34, 35, 36, etc) it’s simply rounded to the nearest valid one anyway.
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As @chrislfa stated it’s really try and error over several days if not weeks.
for me it took me a week to find the optimum for my outdoor setup which i achieved now with 40.2 (blue pro plus stick only, 15ft coax cable, no additional filter/lna).
Also not that the effect between two close values (e.g. 40.2 and 42.1) is sometimes even not noticeable, it depends on the traffic.
Here is my signal level over the last 24 hours. You can see clearly the times with low traffic and how it impacts the measurement.
So it’s always an idea to compare only the high traffic times of the day
Beside this graph, it’s important to keep an eye on the message rate and there the values for messages > -3dBFS and Positions/s
Changing the gain has also a direct impact to these values from my point of observation.
You also need to understand that the blue stick has a limit at around 1200-1300 messages/s as every other stick. Only with an airspy you can achieve twice the amount of messages.
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