Messages per second


#1

Folks,

Not looking for an exact answer here, merely inquisitive.

I have two Pi Zeros, both running PiAware and both also appear to have identical ADS-B tuners with stock antenna sitting on a tin can. One is one side of my house and the other is on the opposite. Both antenna are indoors on a window sill.

No known configuration changes made by me.

Basically they record the same aircraft with subtle differences.

The daily aircraft count is quite close but one appears to register far more messages per second than the other. Normally double but often triple or more.

Why might this be?

Geffers


#2

“appear to have identical ADS-B tuners”

Well are they identical? Maybe just swap them to see if that changes anything ? Or swap the whole installation to see whether that changes anything.

Apart from that, even though they more or less see the same aircrafts, the recepition in one direction could be limited by large buildings furher away. I remember one user here found that a high rise building far away limited his distance he could receive there. Or maybe there is an increase in in the terrain.

Airways might be another reason, if one side has unobstructed “view” to airways, and the other “looks” in the other direction, it might pick up up fewer signals.

One message is enough to count as an a/c, so both stations might see the same planes, but one for longer and further away than the other.


#3

I’ve only recently got the second unit up, intended as a portable unit but just testing at the moment.

Decent suggestion about the substitution, only really just noticed so hadn’t given much thought to it, especially as aircraft count was very similar. I’ll let you know the outcome.

Geoff


#4

Right, I’m almost embarrassed I didn’t think of that :slight_smile:

Changed locations over but kept same hardware and connections, still a difference but not as much. Shall do a few more checks but really is not such an issue that I will put much effort in to it.

As said, aircraft count similar and second device intended as a portable unit - eventually.

Geoff


#5

That could mean a world of difference, specially indoors. I see differences moving inches, literally. All bets are off on indoor installations.


#6

Why not test them side by side in the same place looking at the same aircraft at the same time.

Should then be easy to see directly which system is performing better.

S.


#7

That is a good suggestion, shall try and report back.

Why didn’t I think of that :sunglasses:

Geoff


#8

I now have them side by side, the one that was getting better signal count is now getting worse so I may put them back where they were and live in blissful ignorance that I have little idea what is going on.

All I know is that when SkyView reports a plane is approaching it then appears so I’ll just be happy with that :slight_smile:

Geoff