Dont forget to check your county or local unit of government. Maybe they have already done it with more recent photos. Our county flies the aerials at least once every five years and they have digitized them into their GIS system. We can look at aerials of any parcel in our county and overlay property lines...look up tax info etc for every piece of property. All of this is available from the county's website. So maybe your county or local unit of government has done it too.