Imagery

That is Kibera in 1961. Choose “Nairobi 1961″ from this map. Really, just a preview, it’s going to blow people’s minds, especially with Brian Ekdale’s concise history of Kibera.

Last year in Nairobi, I became aware of an amazing archive of historic aerial imagery, flown by the RAF, acquired over all the British Colonial possessions, several times over decades. The images were used for creating ordnance survey maps … but since then the original images have been sitting in various dusty basements, most recently Oxford. Paolo Paron has a plan to get it all openly online. But in the mean time, you have to go to Oxford, sort through boxes of square images, and request photographic copies. I had the chance to do this back in December, and it was wonderful. 1961 is 50 years ago, meaning these images are out of copyright!

I receieved from Oxford eight largish tiff images. Seeking first to rectify them, I tried various incarnations of map warper (including a local version) but with 30 MB images, it was choking. Next I tried to find a desktop option, and found good results with QGIS georectification plugin. I stitched together 6 of the images, roughly (if I spent more time, would’ve adjusted the different brightness levels and try to align better the two North-South runs that covered Nairobi, one at a slight angle to another). Then loaded a shapefile of Kenya OSM into QGIS, set control points, and warped. Took the resulting GeoTiff onto the generous resource of hypercube, warped the image to spherical mercator using gdalwarp, and after some hints from winkey and crschmidt on #telascience, “gdal_translate -expand rgb”, to take this single band image into RGB, which TileLayers seems to prefer.

There’s a lot more to say about this image, and that’ll be built up in the upcoming new mapkibera.org site. And of course, there’s those 1.5 million time capsule images sitting in an Oxford basement to open up.