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Polar Plot - I'm confused

Posted: Fri Jul 21, 2017 1:08 pm
by MK2wx
Hello Folks,

I just reset the plot as I had a plane outside the plot and the plot did not subsequently extend to the position shown.

While watching the new plot growing, I realised how often this was happening.

So, if a plane has data which is good enough to put up a plane symbol on the map, then why is this not enough for the polar plot to work with? :?

What are the rules of the polar plot in this respect? :?

Re: Polar Plot - I'm confused

Posted: Fri Jul 28, 2017 5:14 am
by evangelyul
yeah, happens to me too, probably has something to do for MLAT aircraft.

i have a pic but unable to post it.

Re: Polar Plot - I'm confused

Posted: Tue Aug 01, 2017 8:40 pm
by MK2wx
Mind you, it's streets ahead of the one in PiAware Skyview! ;)

Re: Polar Plot - I'm confused

Posted: Sat Aug 05, 2017 4:30 am
by evangelyul
i verified same with modesmixer
seems max polar plot range is limited to 360nm/650km or so for both vrs and modesdeco/modesmixer. piaware has a vague 'more than 250nm'.
i live in Montreal but due to many mlat receivers around Toronto, I often get mlat aircaft - specially RJs/ERJs - over 400nm from my position.

Re: Polar Plot - I'm confused

Posted: Tue Aug 15, 2017 4:48 pm
by MK2wx
There is an option switch someplace, I've seen it a few times, it allows one to set it to ignore range above a certain amount, however whether it actually works or not I can not say. I've told it not to mess with anything and to trust what it is told by the radio and it's handlers. Whether it ignores that or not is unknown. I watched in horror as it cost me a 300 mile plus contact a few days ago, I'm terribly underwhelmed by that outcome as it happens. I wonder what else it might be failing to be reliable about? :shock:

Re: Polar Plot - I'm confused

Posted: Thu Aug 17, 2017 7:11 am
by MK2wx
It's now lost at least two more that I know of. More than 300 NM. I set the RX max to 999 Kilometres. This reset my range map, without any warning it would do that!

It's leaking A/C plots like a sieve, failing to plot in significant numbers. In the latest example, I've just watched it fail to plot for a plane it tracked for about 33:34 minutes, last seen 339.85NM range, signal from about 70 to 150. I no longer use a merged feed, so there is no MLAT involved. I don't doubt it's been failing to do it since I installed it, but until now I had not noticed it. It is not something you would expect to have to keep watching out for.

Rather disappointing.