FSXcommon mistakes

arno

Staff member
FSDevConf team
Resource contributor
You need to enter the absolute airport altitude in the GPW, as else the GPW can not calculate the curvation of the earth correctly. In the end the ground polygons are always placed at ground level of your scenery, the altitude is only needed to determine the right curvation.

GaryGB

Arno: Are you stating that we must use AGL -or- (M)AMSL ...in the MCX G-Poly wizard ?

https://en.wikipedia.org/wiki/Height_above_ground_level

https://en.wikipedia.org/wiki/Metres_above_sea_level

I believe it would be best that we utilize appropriate aviation terminology when discussing / working with Altitude:

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Absolute altitude is the height of the aircraft above the terrain over which it is flying. It can be measured using a radar altimeter (or "absolute altimeter"). Also referred to as "radar height" or feet/metres above ground level (AGL). True altitude is the actual elevation above mean sea level.

Altitude - Wikipedia
https://en.wikipedia.org/wiki/Altitude
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GaryGB

arno

Staff member
FSDevConf team
Resource contributor
It's the MSL altitude, not the one above ground level.

GaryGB

Many thanks for that important clarification, Arno !

GaryGB

kmanning

Arno: Are you stating that we must use AGL -or- (M)AMSL ...in the MCX G-Poly wizard ?

https://en.wikipedia.org/wiki/Height_above_ground_level

https://en.wikipedia.org/wiki/Metres_above_sea_level

I believe it would be best that we utilize appropriate aviation terminology when discussing / working with Altitude:

Search Results
Featured snippet from the web

View attachment 45707
Absolute altitude is the height of the aircraft above the terrain over which it is flying. It can be measured using a radar altimeter (or "absolute altimeter"). Also referred to as "radar height" or feet/metres above ground level (AGL). True altitude is the actual elevation above mean sea level.

Altitude - Wikipedia
https://en.wikipedia.org/wiki/Altitude
- private

GaryGB

Hi Gary,

Since the "absolute altitude" is the height of the aircraft above the terrain, it does seem to suggest that the absolute airport altitude would also be the height above the terrain. I think the correct terminology should be the "airport field elevation," which is the height above sea level, or MSL.

Ken.