For those interested in aerial archeology I recommend the work of French archeologist Roger Agache, who pioneered the domain in France in the '60s and '70s and based on whose work tens if not hundreds of Roman-era villas have been mapped in the plains located between the Loire valley and the Northern area of Paris. Just a couple of links: http://www.archeologie-aerienne.culture.gouv.fr/en/discip5-p... (presenting his work in English) and especially this http://www2.culture.gouv.fr/public/mistral/memoire_fr?ACTION... (with actual aerial photos taken by Agache and his team).