Re: Contrail for selected aircraft


algarveastronomy
 

On 06/02/2021 21:37, @chris_aerospace wrote:
So I kindly ask Bev will re-enlighten us how it exactly works. Even in the help topics it doesn't explain fully.
Hi Chris

It's not difficult. The Options..Chart..Options dialog has a section of parameters for the contrail that can be plotted behind each aircraft symbol.

The section includes the Length of the contrail and that has two parameters : the length in Seconds and the length in Samples (points).

So if you want a contrail that is five minutes long you would insert 300 in the seconds box and if you want there to be 50 sample points along that contrail, you would put 50 in the seconds box. In that example, you can see that points in the contrail would be 6 seconds apart.

However, you need to bear in mind that it cannot invent points if there is no new data within that time interval. If, for example, the aircraft is not being received locally, but is being received by sharing, there will only be new position reports in the contrail every minute, so you won't get a smooth curve for an aircraft that is turning.

If you are receiving the aircraft directly, and the signal is strong, you will probably be getting position reports every second or so and in that case, the contrail will be smooth unless you have a very large seconds/samples ratio, in which case it will not be smooth as the recorded points are that many seconds (sec/sam) apart.

I am sorry it is not clear in the Help file but I suppose having created it, it seemed self evident without needing further explanation.

Regards
Bev
COAA

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