Aircraft positions dropping out?

[airdata]

I have had the ANRB since October and last week attached an external attenna with great improvements in coverage.  One question though - I will pickup an aircraft sometimes at 200nm out and it tracks on the map for the first 40nm or so.  Then it disappears off the map yet the list of aircraft continues to be updated with new altitude information for the same aircraft.  Then once inside about 30nm the aircraft re-appears and is tracked until touchdown.   So, why does the position information drop out between 30nm and 160nm when the other information from the aircraft continues to be received?  In some directions the dropout is from 8nm to 60nm and other directions 30nm to 150nm.  Then again in other directions tracking is continuous.

[AirNav Support]

Hi airdata,

Whats the terrain like around your loaction? Do you have sea in that area where you don't get position data.

[airdata]

Location is Auckland, New Zealand which is surrounded by water.  But there seems to be no consistency for the dropout being over ocean or land. 

I have taken 3 screenshots.  Image 2008 (time 20:08) shows ANZ879 at the top of the screen at 182.6NM.  Image 2017 (time 20:17) shows the aircraft just having dropped off the screen with its trail still showing at 107.7NM.  Image 2023 (time 20:23) shows the polar diagram and the aircraft info strip being updated with the altitude changes, distance still shows at 107.7NM, but still no position on the screen.  Now at 20:32 the aircraft returns to the screen at 9.0NM at 3500ft.

On a different issue the image 2017 also shows 2 aircraft with the same flight ID.  The correct ID belongs to ZK-OKH (not ZK-JTS).  I have noticed this several times recently.

I am using the 3.0 beta version at the moment.

[LiveATC]

This may be multipath signal , are advised to install an additional antenna amplifier

[John Racars]

On a different issue the image 2017 also shows 2 aircraft with the same flight ID.  The correct ID belongs to ZK-OKH (not ZK-JTS).  I have noticed this several times recently.

Hi Airdata,

This looks verry much on a problem I have seen on my screen as well. I reported this to Support allready some weeks ago.

I suppose they are trying to find a solution for this.

[EK01]

Try zooming in and out when you see the purple trail on the map. Sounds like it might be the known bug in version 3 beta which, I believe, has now been sorted for the full release.