In another thread someone posted a photo of a sign at an airport gate giving the geographical coordinates. I looked it up on the map and found some discrepancy and so I posted asking but got no reply or interest in that thread. I am still curious as to why the geographical longitude marked at airports do not match the WGS84 coordinates. Anyone?
I would question the provenance of the photo. Clearly the longitude is wrong, but according to my investigation Tan Son Nhat International Airport
does not have a Gate 10. The airport was remodelled in 2007, so maybe there used to be, although that still would not explain the wrong coordinate.
Before concluding all airport gate location signs are wrong, I would look for some known good data.
Update: gates 10-14 are described as "bus gates", i.e. passengers are taken by bus to plane on the apron. I'm not sure those are fixed locations, so I'm still not convinced this is a genuine sign.