Cambridge University Launches Archive of Aerial Photos Going Back to 1945 | Hacker News Reader

Cambridge University Launches Archive of Aerial Photos Going Back to 1945

theguardian.com

88 pointssohkamyung15 comments

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So much potential here.

A few years ago I put together a project overlaying aerial photography of Denver from 1933 on modern satellite imagery.

Check it out if you're interested https://oldcity.io

Edit: I have the imagery to do the bay area in 1939 too, just have not gotten around to it.

This is awesome. How did you work out the position of the maps so they overlay correctly?

Thanks! It was a lot of fun and simultaneously a big headache.

The original bounds came in a shape file from the city's open data catalog [1].

After that it becomes a multi step process that has to be repeated at each zoom level.

So say zoom level 20:

+ Size the image where 1 px = 1 mercator pixel @ zoom level

+ "Seat" the image. Map tiles are usually 256x256 and your large image probably does not align correctly. i.e. probably (width % 256 != 0 && height % 256 != 0). So you have to calculate those offsets and add them as a border to the huge image.

+ Tile the large image into 256x256px tiles. (~240k of them at zoom level 19!, 60k at 18 etc etc.)

+ Repeat @ next zoom level

+ Store all the raster tiles on S3 and put CloudFront in front

+ Have your app implement a custom tile overlay (iOS, Android, GMaps JS all support this)

+ ???

+ Profit (just kidding, this costs me money)

There might be a better way to do this. I couldn't find a lot of good resources when I set out on the project so I made it up as I went along.

[1] https://www.denvergov.org/opendata

Direct link to the photo archive: https://www.cambridgeairphotos.com/

thank you

Google Earth supports historical imagery, and it'd be neat if these images could be added.

Based on the age I suspect they're missing a lot of necessary meta-data, though. Maybe it could be crowd sourced in a "captcha" somehow?

I didn't know this... how can you access historical images in Google Earth?

Here's how: https://support.google.com/earth/answer/148094?hl=en

What an interesting archive! Pity the website has the most terrible UX, whereby it's impossible to browse the pictures easily or search them well. Or at least if it is, they don't make it easy to figure out how.

Impressive pictures, it is strange to see colour pictures from the forties in focus, compared to all of my family's blurred snaps.

Good though the pictures are the UI for this website really doesn't do the images justice, with 1/2 million to be added I assume that a more enticingly navigable website is in the works.

Text search for towns would be helpful by year, or via points on a map. Paging through images in no apparent order 10 at a time through 170 pages gets me climbing up the wall.

Ah, here's a map navigation of the pictures just in case anyone else is gingerly dismounting the wall:

https://www.cambridgeairphotos.com/map/

Now slowly banging head against aforementioned wall

https://www.historicaerials.com/viewer is amazing for this purpose. They've aggregated decades of aerials and topo maps covering most of the US.

A great way to analyze urban development patterns and answer local historical questions.

I enjoyed being able to see my grandparents’ region from the sky above Derry and County Down (N.I.) before they moved here.

I’m happily anticipating what’s to be seen around Largs and Fairlie Moor (Ayrshire) as well as Uphall/Broxburn/Kirkliston (near Edinburgh) for my other grandparents!

Thanks for posting this!

Edit: typos/grammar

Slight aside: I was searching previously and came across a few different archives - including the UK's National Archive - with historic aerial photo collections. It seemed like there was much needless duplication.

I wonder if the people involved here considered adding the images to an existing aerial photo archive?

Good job!

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