detect runway centre line

[Jason Fayre]

Hello,

For the flight sim accessibility software I'm writing, I've been asked if there is a way of detecting when a user is on the runway centre line, either during take off or landing.

I see that the r5.csv that is produced by Makerwys give CentreLat and CentreLong fields, but I'm having trouble figuring out what to do with them.

Is this the position of the centre line at the start of the runway?

Also, any reason this data isn't included in the runways.xml file? I'm using python, and XML is a bit easier to deal with.

I'm sure this is possible to calculate, since I've seen other software give the number of feet left or right of centre when landing.

Any help would be apreciated.

 

 

 

[Pete Dowson]

2 hours ago, Jason Fayre said:

I see that the r5.csv that is produced by Makerwys give CentreLat and CentreLong fields, but I'm having trouble figuring out what to do with them.

Is this the position of the centre line at the start of the runway?

The centre line runs all the way down the runway. You know the direction of the runway and it's start and end, so it's just a matter of trigonometry.

2 hours ago, Jason Fayre said:

Also, any reason this data isn't included in the runways.xml file?

What data is that? I think the xml contains the same information. eg:

<Len>9988</Len>
<Hdg>55.050</Hdg>
<Lat>53.345268</Lat>
<Lon>-2.292515</Lon>

and of course, similarly for the opposite end.

As to whether the lat/lon give the position at the exact centre, I would assume so (where else)>. MakeRunways merely extracts it from the BGLs. Check if you like, either in the sim or using ScruffyDiuck's Airport Design Editor (ADE).

Pete