Taxiwaypath - Taxiwayparking

[ronh]

Hi All,

I am trouble understanding TaxiwayPath start and end for type PARKING.

The start and end points are TaxiwayPoint or TaxiwayParking.

The SDK says for TaxiwayPoint:

Identifier assigned to this taxiway point to make it unique inside of an airport. This identifier must be unique for all TaxiwayPoint and TaxiwayParking locations inside of an Airport.

When I look at SDE decompile of BGLs. Both TaxiwayPoint and TaxiwayParking can have the same index.

The SDK says for TaxiwayParking:

Identifier assigned to this taxiway parking location to make it unique inside of an airport This identifier must be unique for all TaxiwayPoint and TaxiwayParking locations inside of an Airport.

But, I can have a TaxiwayPoint type NORMAL index = 11. AND I can have a TaxiwayParking index = 12.

I can also have a TaxiwayPoint type NORMAL index = 12. AND I can have a TaxiwayParking index = 11.


Now I can have a TaxiwayPath of type=PARKING start = 11 and end = 12 - So which is which?

The SDK does not specifically say the the end should be the TaxiwayParking index and the start should be the TaxiwayPoint index. However that is what I see in my test cases.

 

[scruffyduck]

Hi Ron

I am no expert here except that is seems OK that parking spots and taxipoints can have the same index. I assumed that if the path type is parking then one end or the other is a parking spot and therefore it can have the same index as the taxipoint at the other end. However it seems that is not the case based on what you have said.

I have to say that I cannot be sure that SDE is handling these things correctly but I guess someone will have checked this as I don't have any bug reports on this area.

Hopefully one of the other guys will be able to give a more definitive answer.

 

[ronh]

Thanks Jon,

I believe that SDE is handling things correctly - My assumption that the TaxiwayPath type PARKING is that the end index is the TaxiwayParking point all the time. This seems to be the case. I am having trouble with my XML viewer in that the taxi path does not display properly.

The SDK is misleading in that the path start and end index:

start
Starting point or parking index
Index number of taxiway point or parking space to start from.

end
Ending point of parking index
Index number of taxiway point or parking space to end at.

I feel the SDK should specifically say:

start
Starting taxiwaypoint index
Index number of taxiway point to start from.

end
Ending point of taxiway point or parking index
Index number of taxiway point or parking space to end at.

 

[jvile]

Ron

What I did to learn taxiway parking and paths was to make a simple runway with AFCAD and a simple parallel taxiway. I then decompiled to see how it was indexed.

I the added a Parking spot and again decompiled to see how that parking spot a taxiway path related to the indexing.

Each time I added something I woud decompile and review until learning the pattern of indexing.

The taxiwaypoint (number) helps in understanding if the link line is on a parking spot or a taxiway path when index.

 

[GHD]

Hi Ron,

You are correct. The start point of a segment is a always a taxiway point index, if the taxiway path has type "PARKING", the end point is a parking index else it is also a taxiway point index.

George

 

[ronh]

Hi George,

Thanks for verifying that. I like what you did. How did you plot the points?

I am having a heck of a time ploting taxiways. I am trying to take the start and end points (lat/lon) and create a rectangle based on calculating the distance between the lat/lon start and end as length and the width param provided in the XML. They will not rotate to a proper angle.

 

[GHD]

I am having a heck of a time ploting taxiways. I am trying to take the start and end points (lat/lon) and create a rectangle based on calculating the distance between the lat/lon start and end as length and the width param provided in the XML. They will not rotate to a proper angle.

That should work. I don't attempt to display the width, I just use CDC MoveTo/LineTo calls with either one or two pixel widths.

George

Ah, I see where you may be going wrong. You need to calculate separately the delta distance in longitude and latitude to get the vector in x/y space. If you wish to create a rectangle, apply the width normal to this vector.

 

[ronh]

Thanks George,

I used your suggestion of lineto. I was just getting too fancy - need to stick to KISS. I used a line and set the width to width of taxiway. I actually get the airport to resemble the real one.