Bol200 and Felippo,
The attached overlay give you a precise location of the findings from the recent Science article by Andrea Ninfo and the write up by Andrew Curry. Below are some of the details.
It is particularly interesting to look at the various GE images and extrapolate the further extent of the hidden city

Ancient Roman City Rises Again

Source: ANDREA NINFO ET AL., SCIENCE (31 JULY 2009)
and
Andrew Curry ScienceNOW Daily News 30 July 2009

From the ground, a 100-hectare site just north of Italy's Venice airport looks like nothing more than rolling fields of corn and soybeans. But it's actually home to a buried Roman metropolis called Altinum, considered the precursor of ancient Venice. Now, using sophisticated aerial imagery, researchers have brought this city to life once again......... more: http://sciencenow.sciencemag.org/cgi/content/full/2009/730/1

and BBC story: http://news.bbc.co.uk/2/hi/science/nature/8177529.stm

It is very interesting to look at the "historical" Google Earth images. Particularly 2002, and May 23, 2003 show the possible extension to the south and the north west of the ancient city.The September 2004 images shows additional intersting detail. Of course not as amazing as the false colour image. Of course the overlay is approximate and seem to be somewhatr diffrent because of slight shifts of each of the images.