1cm to 2cm per pixel
you know not what you ask....
theres only way to do that cheaply, buy an slr/prosumer camera and some long poles. Just walk/drive around with the camera above your head, you can shrink the pics to get the 1 cm per pixel u are after. Google earth streetview done by car, u need to do do the same except point your camera down at the ground
U can get acces to roof tops, with a bit of blag and a legitimate reason. Stitch the whole lot together
1cm per pixel is realy close range , thirty foot? from target , if the cam is 10ft above ground level u will get good quality pics that u can shrink down.
if its just any location....just hit google images and use that, or go to a photo library
Q whats it for anyway ?
lol , just buy a big bunch of helium ballons and 50ft line, walk round with that raising and lowering the line as u need to, attach an HD video cam and leave it running. sift through the footage after....this is the safest and most sensible way and you can do it yourself
its way to dangerous to fly an RC heli or plane that low over people and buildings densley populated areas, crash and u could kill someone , wreck property, get nicked by the police....yeah its been done, but u aint gonna pay someone pennies for the risk so u can profit
2000 dollar rc plane/heli and a very skilled pilot , and a prayer theres no radio interferance, and do it on wind free summer day