|

FS2002 Scenery
GPS and Map errors
Problems using chart and GPS data for designs.
The two airfields shown in the screenshots here
are Jurby and Andreas.
Andreas (top) was created from GPS readings
from each threshold.
Jurby was created from supposedly accurate airfield
drawings with Lat/Long values converted from OSGB36 to WGS84.
Both airfields have been compiled without the
airfield polygons so that the runway layout can be directly compared with
the VFGM scenery.
 Andreas airfield. Technically disused
but it is active with microlights and gliders.
The airfield is offset
by quite a margin. GPS has been useful in that the layout is accurate but
the runways need rotating very slightly anticlockwise and the whole airfield
layout needs moving southwest. The offset is approximately 440ft.
I
can't offer any sound reason why the offset is so great from
(theoretically) accurate GPS data - a Garmin 196. For most purposes
(including flying) it would be accurate enough but scenery design demands
much higher accuracy!
|
 Jurby
airfield is in very good condition but is rarely used.
Here the runways
are more accurately located
but will still require adjusting. The slightly oversized scenery is a
hint that the airfield may have been built using a photocopied map (it
was, but I only discovered that afterwards). This is a common problem -
copiers may create stretched or oversized copies, sometimes in length only but also
in length and width as shown above.
Note: The original WW2 tower is just to the right of the red
centre cross and is used when Jurby is active (occasional flying
displays and air races). Above and to the left of this is the hangar
base for the
ill fated Airship Project which folded before the first airship was
completed. Only the base
remains now - the structure was dismantled several years ago.
|

|