Drop since update to new OS and 3.6.2


#1

Updated to stretch and 3.6.2 via new flash of Mem Card. Put my settings back to where i was and now Im down about 150-200 Planes a day and a 75K to 100K drop in Positions. Would it not remain if the Gain was set the same with no other change?


#2

There was no change in the ADSB decoder. The latest changes were for the OS update and the Skyview update. This should not change the number of planes seen.

Check that the gain settings are correct:

piaware-config -showall
or set it with
piaware-config rltsdr-gain -10

and then restart the ADSB decoder with

sudo systemctl restart dump1090-fa


#3

Dave
that is my thought, my gain setting is the same as the old OS and 3.6.2. I just thought I would move up to the new Stretch since eventually you will no longer support Jessie. So my system should see no
changes what so ever. Yet, there it is, on the day I switched I went from 1500+ a day to 1300+ a day. No other changes at all.

So setting AGC on with -10 … I cant do that, with the Prostick Plus and the Flight aware antenna I get saturated at that setting.

when I get home today Ill check and see if a connection went wonky picking the PI up to get the Mem card out.


#4

1 day differences can be that large with weather and other stuff.

If you have to compare at least use the same day of the week.
Maybe have thunderstorms that day so planes avoided you area?


#5

Been 3 almost 4 days in a row now.

Ive been running in the 1500s for a couple months. Now in the 1300s for the last few days and it occurred when I switched to the stretch from Jessie, and it made me wonder what is going on.


#6

Only thing i can think is of: you bumped a connection or the antenna somehow?

How does the range distribution look compared to a week ago? You can check on your flightaware feed page.

Other proposal: check in the local logs if the gain is really set to the correct setting or it somehow didn’t apply.

Just throwing out ideas it’s hard to troubleshoot something like this.


#7

I have same issue when trying to update 39602 to an RPi 3B+.

This is my Skyview with 3.5.3 this morning.

This is Skyview with 3.6.2 this morning.

Gain settings are the same and all parameters of the piaware.config file are standard except for setting static IP address and Feeder ID.


#8

Raw message rates are dramatically different there (5x difference) and there were no changes to the demodulator between 3.5.3 and 3.6.2, so I think you have something else going on there.


#9

The only visible difference I see is the 3.5.3 unit has been displaying a message “56% of UDP multilateration traffic sent by piaware is not reaching the FlightAware servers. This may indicate a network issue” ever since we moved to cable internet. Our IT techs have been in contact with you but no resolution made.

That message is gone when the 3.6.2 software is active.


#10

Probably a stupid question but could it be because of the new OS (stretch) and not the decoder itself somehow?


#11

Another stupid question regarding OS Stretch, notice that since updated to Stretch and 3.6.2 that a “Bermuda Circle” has developed around my location with a radius of about 5 to 7nm depending on aircraft height. Aircraft entering the circle will disappear before reappearing when they reach the other side. Change the gain from -10 to 48.0 and the circle is greatly reduced. Anybody else seen this situation?


#12

No, but that would be, for example, consistent with signals in close range being to strong and not being decoded. -10 is the highest gain you can use, (around 54), maybe you had set a different gain before the update?

If you run the gain script on a piaware image, the last value used is kept in piaware-config, I inadvertently used a lower gain setting than Intended.


#13

I have the latest rasbian with piaware, but noticed a drop.
Not sure, I thinkered with the antenna also (inside) will post a picture of my creative (lol) setup later :slight_smile:


#14

Bingo!

I would focus on the antenna. My numbers dropped by 50% after upgrading Piaware and tinkering with an indoor antenna at the same time. I spent a lot of time, and money, for 6 months until ‘accidentally’ finding the cause.

One other thing to keep in mind is that indoor antennas are much more susceptible to very small changes, literally. Moving a couple of inches can ‘make or break’ a setup.


#15

@Dxista

I think so, My antenna is a can with a little bit of wire sticked inside with the complete recever stick (ground) boulted to the can.

I will make a picture when I can, It’s remote location.

But still it works very well. I get planes about 400 km away even with inside antenna
about 50+ in peak. But I’m close to AMS airport.

cost: rpi, And I think Noelec dongle a can and 10 cm wire copper lol

$100 max, I think less :wink:


#16

Thanks Biekerc for your heads up. I have never played around with the gain setting before and only recently became aware (with Stretch) of being able to adjust the gain.

Your comment re the strong signals makes sense and looks like I just have to live with the situation. It just seem strange that it came about with the upgrade to Stretch and 3.6.2 and not before.


#17

Regarding the raw message rate previously reported, could you recheck the 11414 site for a recent improvement.

Our cable network has a 1400 MTU rate limit and we have reset the /etc/network/interface file to that value for the wireless.

Thanks for checking and any feedback!

Lowell