I've never seen markings like these circle thingies. Can someone tell me what they're for?http://forums.avsim.net/user_files/117550.jpgSidney Schwartz KPDX

compass alignment marking?Murrell

Ah yes....Nazca airport.

I think it's just the division between taxiways. Imagine they were grassed...http://ca.geocities.com/[email protected]_BigO_new.jpg

gonna give it a stab, deicing parking?

Streetcar turntables (:

nazca lines, lol. :)jeff

Wrong place for a compass rose. Would have to much "metal" interferance with aircraft taxiing, taking off, landing right next to you...:-outtahttp://publish.hometown.aol.com/p3superb/i...s/sign_name.jpgThere is a fine line between "hobby" and "mental illness".- unknown"My daddy gives me up, to fight for you"- a US Military Members Child

They are simply 'NO TAXI OVER' zones...Like those stickers on the wings "No Step"... Well those mean "NO TAXI" and you are not supposed to taxi over them. They are used to divide the actual taxiway routes.They could be grass, but it would cost more.George DorkofikisAthens, Greecehttp://online.vatsimindicators.net/811520/1704.pnghttp://www.precisionmanuals.com/images/forum/betaimg.jpg

Hi George,"No Taxi" zones makes sense, except for the markings within the circles. The markings are different in the two circles, and neither of them make any sense. If the message being conveyed is "don't taxi here", why not a simple and consistent pattern of diagonal lines, or a solid color, or something else with an obvious meaning?Sidney Schwartz KPDX

UFO landing pads. Although similar to helicopter pads, these have marking to afford visual orientation cues to the UFO pilots. They are as yet untested. R-

Any possibility of chopper pads? If those small items around the circumference are runway lighting I might think that might apply. Maybe that specific airport requires choppers to hold short near the runways and take off or land there to "go with the flow". I also note what appear to be taxi lines between these two circles.What airport is this? Area 51?

>UFO landing pads. Although similar to helicopter pads, these>have marking to afford visual orientation cues to the UFO>pilots. They are as yet untested. R-That would explain alot of the local population. :-badteethSidney Schwartz KPDX

>What airport is this? Area 51?KPDX Portland International, Portland Oregon.Here's some more examples, same airport. So for the "no taxi" explanation seems like the most likely one.http://forums.avsim.net/user_files/117686.jpgSidney Schwartz KPDX

Geez you guys, anyone can see those are a new form of crop circles :-) That Google map is really amazing btw.Todd