Since there is no new Google Earth photo of my pond site, is there an easy way to utilize my iPhone as a way to measure the approximate size of my pond. It is a small pond, I think close to one acre in size.

I need the measurement to calculate water volume in order to pick the right aerator.

http://findpondsize.com/mobile.php

Also, if you want Google to update a specific location, you can go to the menu on Google Earth, click on "Feedback" and select “I would like to recommend an imagery refresh” in the feedback window.

Google Maps surely has an image of the area prior to the pond being installed and you can get real close to it's surface area using the measuring tool they offer (and your imagination). That will be close-enough for sizing an aeration system given you can closely guesstimate an average depth. An aeration system, IMO, should be oversized with a safety factor of 1.5 to 2 X.