Anybody else use them? I used to use them once in a while but have decided that using them on pretty much every job really helps out a lot. I get them from Earth Explorer. The ones around here are mostly from the late 50's to early 60's are about the earliest you can get. They aren't orthorectified?ÿand I downloaded a program that may orthorectify them but I?ÿhaven't gotten that far yet to try it. There is so much visible information on them. Old buildings that are long gone, old fields and fences, now?ÿheavily forested land. A great asset. I am amazed at how much of the areas I work in were open fields in the 50'-60's.
The site says it has aerials back to the 30' but I've not seen anything near that early anywhere around here.
I use them quite a bit, although it depends on the type of project. Many areas round these parts have pretty good coverage back into the 1930s.
Loyal
I use them here (Tasmania) and thankfully have access to fully rectified imagery going back to '50's.
Recently I was looking at an old road survey, several kms long, from 1800's of which there is no trace on the ground other than a 150 metre stretch of fence.
I was only interested in where it crossed an early land grant and that fence was the only evidence.
The 1950 aerial showed same fence in same position.
Agree those old images are a wealth of information and helpful in tracing old surveys where their finer details are long gone.
Same here re vegetation. Trees, no trees then trees again only to be cleared once more
They help out quite a bit. I did a survey last year against another survey that used a Poplar as the original corner. I couldn't get it to fit anything. I tried and tried to figure out why he decided this Poplar was the original called out in the late 1800's deed. I downloaded an old aerial and it was a big field in the 50's no trees in sight in that area. Once I ignored his Poplar everything fit together quite nicely except his entire survey was way out of place. Many details about this but, in short, I'm glad I took the extra time and didn't blindly agree with him.
Working on a survey right now where it?ÿcalls for a long ago?ÿmoved road. Even in the 50's, it was difficult to see. But all the deeds go to this road and none of them have any calls stating where it is. At least we know where to look now. It won't be easy, but I'm sure when we go out there tomorrow we will be able to pick it out in places since we have that old aerial to help us.
I've found that even some of the recent Google Earth images show enough difference in vegetation color to trace roads and railroads across farm fields several decades after abandonment.
I've used historicaerials.com to see places around here with 1930's photos.?ÿ?ÿ
UCSB has a treasure trove of old aerial photos. Most of them are scanned. They have scans of the 9x9s which can show features better than the orthorectified photos.
http://mil.library.ucsb.edu/ap_indexes/FrameFinder/
USGS has pbotos going back to the 1930s for much of the country.?ÿ These are invaluable for riparian boundaries, and dating fences and roads.?ÿ
https://lta.cr.usgs.gov/Single_Frame_Records
I was speaking of the areas I work in. They don't have any that I have found, so far, on anything I've surveyed. I may get a job that does have some 1930's coverage in the future. Earliest I have found is April 1956 so far. But they do have a wealth of detail.
https://www.historicaerials.com/viewer
This one goes back to at least the 60's for most everywhere, and you can alternate between aerials and the quad.
We have aerial photos going back to 1938 and use them all the time. It's amazing how the old hedgerows and lines of occupation were visible back then are gone now in the more recent imagery.
I stumbled on them while searching one day in our GIS drive looking for something different, and now I always import them into the drawing when doing a boundary. Ours are all Geo-referenced to so it's handy.
https://www.historicaerials.com/viewer
This one goes back to at least the 60's for most everywhere, and you can alternate between aerials and the quad.
Thank you!
UCSB has a treasure trove of old aerial photos. Most of them are scanned. They have scans of the 9x9s which can show features better than the orthorectified photos.
Be careful with scanned photos. Depending upon the direction of scan features like fences can occasionally fall completely between the scan lines and go AWOL. Always worth checking images from adjacent flight lines if you can't access the original prints.
UK is fairly fortunate in that most of the country was covered during the mid-1940's (when the RAF were practising for a "big-event"). After 1945 the coverage was regularly flown as training exercises up until the late 1950's. It's rare that I haven't been able to find suitable imagery from that period - generally scaled at between 5000 and 10000
I'm not using 9x9s for scalable mapping. I wanted to know if a certain building is visible in the 1937 aerial photo. The orthorectified version was washed out just a bit so all that can be seen is a light colored field in front of a dark colored field. On the scanned 9x9 I can just pick out the roof which is about halfway into the light colored field. The building exists today but I wasn't sure if it existed in 1937. The contrast of the old photos is problematic.
I was speaking of the areas I work in. They don't have any that I have found, so far, on anything I've surveyed. I may get a job that does have some 1930's coverage in the future. Earliest I have found is April 1956 so far. But they do have a wealth of detail.
Maybe, you are looking in a different place? I didn't think there was a way to search for individual frames on your own. You have to contact them by email and they get back to you a few days latter with what they have.?ÿ I see that on their web site they only list Oklahoma photos back to the 50's, but they are available for the the 30's and 40's too.?ÿ
The USDA did a huge campaign in the late 30s. Many of the better parts of the collection can be found in locsl university libraries. The trick is finding someone who knows they have it and getting access..?ÿ
I'll check into that. I download the single frames from Earth Explorer and the oldest I've found for this area is 1956. Thanks.
Oh, I see what the confusion is. The link I posted just goes to the earth explorer web page. The page I was trying to link to doesn't seem to exist anymore.?ÿ
Any area that was mapped in the 30s should have photos from then.
I will try to find some contact information on Monday when I get back to my work computer.
I have an old aerial image from 1938, but the photo is not orthorectified and the relief in the area distorts the image quite a bit. Does anyone know of a way to orthorectify old photos? Is it even possible without the metadata of the old photo?
Not really. Even with all the metadata to enable you to orientate it correctly there isn't any way from a single photo to deduce the relative heights of objects and hence correct for any "lean" (unless you already have known dimensions on the objects).
If you can find an adjacent frame, or better still the frames before and after, it might be possible to form a digital stereo model. I've done that several times using Photoscan. Plan position and height would be OK, but you won't get much, if any, realistic rendering to vertical faces (because there wasn't much to see of those on the original images).