Subtraction Architecture: Tracking Changes with Google Earth and Google Street View
Updated: Jul 5
For this portion of our project, we have endeavored to establish robust visual documentation of vacant lots in St. Louis, Philadelphia, and Detroit. On field visits to each city, we have taken photographs of the lots under examination. However, in order to augment our photographs, we have made use of Google Street View and Google Earth. These platforms allow for the visual tracking of vacant lots over time, as serial images bring important patterns and shifts into relief that otherwise flow below the radar of anyone who doesn't live on the block.
In tracking changes, we are interested in the most granular level, down to the specific parcel geographies, their spatial configuration and content, their utility bundles, and their architectural compliment (know as "improvements" in real estate law). We are particularly interested in how demolition of buildings and the resulting vacancy of land changes the urban character of a block and its surrounding neighborhood. After all, this scraping away of architecture comprises one of the hallmarks of disinvestment under the sign of racial capitalism in U.S. postindustrial cities.
Google Earth and Google Street View provide excellent data for the study of land and land uses, but come with limitations. Google Street View images taken at specific coordinates, for example, will differ from one pass to the next not only for obvious reasons of the changing content of scenery, but also based on the location of the vehicle on the street, the surface topography of the road, the height of the rigging, the number of lenses and rotational position of the camera, and the stitching algorithm that blends the images together ('stitches and glitches'). Particularly on narrow streets, it can be difficult to obtain a usable image along a plane perpendicular to the camera lens.
3000 Block of Vine Grove Ave via Google Earth, showing one of the five properties selected for close study. Left, Dec 2002. Right, Sept 2022.
Google Earth images, meanwhile, will differ based on the resolution of the orbital camera, the effective 'altitude' of the view, the degree of distortion in the curvature of the Earth, and the stitching of images from separate satellite passes over the region. Over the past 20 years, many refinements and improvements have been made to the orbital imaging technology used by the Geo-Eye One satellite and processed in the Geospatial Intelligence Agency. Additionally, Google Earth images are highly dependent on weather in ways that Street View images are not; heavy cloud cover can partially or completely obscure a location from view.
Another limitation in the use of these platforms is that Google deploys its image capturing and display technologies at different rates from one location to another, both within a given city and between cities, regions, and nations. One street in St. Louis might have 8-10 separate vehicle passes stretching over 15 years (the earliest year available for most of the U.S. is 2007). Another street in St. Louis might only have 2 or 3 passes displayed. The differential is even more significant in regions of the Global South, where Google Street View cars might only have passed through once or twice, if at all.
With those limitations in mind, we can extract a range of data points from Google Street View and Google Earth images. In addition to geolocational position and compass heading, we can track the presence and condition of buildings and lots, the condition of the adjacent and surrounding infrastructure, the presence of trees, bushes, gardens, fences, rubble, refuse, and even evidence of habitation. Google Earth, moreover, provides contextual information such as nearby churches, schools, and other institutions as well as the extent of land vacancy in the surrounding blocks.
We have used these visual tools, along with our own photographs as well as city land and deed records, to assemble the outlines of stories of five properties in each of the three cities in the study. We also have created Flickr albums for St. Louis, Detroit, and Philadelphia.
You can read more about our approach to architectural subtraction in the Field Notes section. Check it out.