FlightAware Discussions

Correlation between messages, positions and aircraft seen

Morning.

I’m now receiving far more than I had previously and am curious about the ratio of messages, positions and aircraft seen.

At times I am receiving 400 plus messages per second and hitting almost 80,000 positions per day. Aircraft seen can be up to 450 per day, I’m on the north west coast of England, close to Liverpool so it (at the moment) isn’t the busiest place sky wise.

It’s probably a piece of string and how long it is question, but do these figures seem reasonable to the more experienced users/members, please?

I’ve installed @wiedehopf ‘s graphs and will try and work our from them how the station is performing after a week or so.

Thanks for any advice.

Kev

For the second and third question you can simply check anybodys profile.

For me (mid of germany) it’s pretty similar. The number of messages and the number of aircraft are going up and down by factor 8-12 in many cases.
Deviations of course can occur.

However it depends on the equipment and the environment. You can get either a higher or a lower message rate compared to the number of aircraft.

I am using the blue Pro Plus stick with an additional filter in front of it. It turned out that the natural limit of this chip is approx. 1300 msg/second while an Airspy can go up to twice the amount.

This is mine the last 48 hours

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I think the question really is quite complex. It certainly is to me. There are so many variables.

When I started out years ago, I whacked a home made antenna up in the loft and connected it to the cheapest DVB-T stick I could lay my hands on with a spare piece of satellite cable. I was perfectly happy with what I got but like so many pursuits, you sometimes don’t realise what you are missing out on or how little you know about the subject for a while.

As @foxhunter says, you can compare your results with those of other feeders but that doesn’t tell the whole story. Take mine for example, https://flightaware.com/adsb/stats/user/technodevotee#stats-100624. The problem is that you can’t tell from the information there what gear I have or how many 'planes actually fly through the airspace ‘seen’ by my antenna.

I can tell you that I have two home made 1/4 wave ground plane antennae (spiders), in the loft right up under the ridge tiles, one on each side of the house. Each of them has an RTL-SDR triple filtered LNA underneath and that is connected to an RTL-SDR Blog V3 dongle.

I’ve gone though all the gain settings over a the last year to find the setting that gives me maximum range, positions, aircraft etc. and I settled on a gain of 38, which I reckon it is about as good as I’m going to get with my setup.

I could probably do better with a proper antenna and better cable but unless you are a perfectionist with an unlimited budget, you have to stop somewhere.

Even If I was a perfectionist with an unlimited budget, like most people there a limit to what I can do. Short of moving. As much as I’d like to, I can’t cut down other people’s trees, demolish other people’s houses or remove the hills that are in the way of my view to the horizon.

I used to get a peak of just under 1800 msgs/s with an rtl dongle. That was with a filtered pre-amp at the antenna, not a dongle with built in amp:

If you look at your profile on here, scroll down and compare your figures to “nearby sites”. That’ll give you a good idea of how your receiver is performing.

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Wow, i thought i have read something about that here in the forum because it was a discussion about the blue FA stick. The highest one i got was approx 1350 msg/sec