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certain planes not showing on vrs

Posted: Wed Aug 29, 2018 8:35 pm
by ivan
hi all
i am not really a pc buff but can do basic things. ok so let me try to explain my problem, i have been tracking planes on the web via the ads-b exchange,virtual radar24 ect.
so next step was to purchase dongle and set up vrs, all is well seems to work fine tracking upto 180 planes . however my location is midway between marham, lakenheath,and mildenhall. i track planes and helicopters on ads-b exchange but do not see them on my vrs. i tracked a hurricane the other day it flew straight over my house, again it showed up on the internet vrs, and flight24 but i could not see it.
any help would be appreciated.

Re: certain planes not showing on vrs

Posted: Thu Aug 30, 2018 4:05 am
by Radio Active
Not all aircraft use full ADS-B which transmit their location, Some of these aircraft you cannot see are most likely using Mode S transponders or other types of transponders (depending on the aircraft) and are tracked using MLAT (multilateration) a method of tracking aircraft via a number of ground receiver stations (that would be picking up that aircraft) using a MLAT client software and data sent to a MLAT server where all the data is put together and returned for display, Not all aircraft can be tracked.

Re: certain planes not showing on vrs

Posted: Thu Aug 30, 2018 7:45 am
by skaw
Easiest step would be to use your setup to feed data to flightaware. By doing so you will get the results from MLAT calculations back to yourself. You can then set up a second receiver inside VRS using that datastream to display these results.

Re: certain planes not showing on vrs

Posted: Thu Aug 30, 2018 6:22 pm
by wn0nfi
Some times I will get a plane that will give me latitude & longitude but the plane will not show up on the map. Do I not have something not set right?

Re: certain planes not showing on vrs

Posted: Sat Sep 01, 2018 7:57 pm
by kiwikieran
Does that plane show on the side panel? Where are you seeing it has lat/lng?

Re: certain planes not showing on vrs

Posted: Sat Sep 01, 2018 10:46 pm
by wn0nfi
kiwikieran wrote:
Sat Sep 01, 2018 7:57 pm
Does that plane show on the side panel? Where are you seeing it has lat/lng?
Image

Re: certain planes not showing on vrs

Posted: Mon Sep 17, 2018 11:00 pm
by agw
Sorry for the late reply.
wn0nfi wrote:
Thu Aug 30, 2018 6:22 pm
Some times I will get a plane that will give me latitude & longitude but the plane will not show up on the map. Do I not have something not set right?
If the aircraft position is stale then it won't be plotted. A stale position is one that has not changed for at least 60 seconds + the display timeout in seconds. If the aircraft is on the very fringes of reception then you might not get a valid position come through for a while but you could still be getting Mode-S messages coming through. The non-position updates keep the aircraft in the list but without a recent-ish position it won't appear on the map. You can add the position age as an item to the aircraft detail display.

If you're only getting two aircraft in the aircraft list then I suspect it's either very late at night, or your antenna might not be suitable for picking up Mode-S or you might have the antenna in a suboptimal location. If you can get hold of a Mode-S antenna (they're fairly cheap) and stick it outside or high up near a window with a good view of the sky then you should be able to pick up more aircraft and not see so many stale positions.

Re: certain planes not showing on vrs

Posted: Thu Sep 20, 2018 2:54 pm
by wn0nfi
Thank you for the info. I did get a better 1090 antenna that did help some. I see about 10 planes with the new antenna. I do live about 120 nautical miles from a major airport.