Jerusalem is a city famous for its walls. The walls of the old city and the infamous separation wall are some well-known examples. Yet less known is another invisible wall that encircles the old city and its surroundings. Centred on the Haram al-sharif, Temple Mount, and spanning approximately 3km in diameter, a cylindrical digital barrier known as a “GeoFence” extends from the ground and up into the skies, set to prevent drone flights into or from within the area. This technologically restricted zone follows the geographic coordinates of an already present regulatory No-Fly Zone (NFZ) that has been set and enforced by the Israeli security apparatus for more than two decades.
The geofence is a recent technological layer added to an increasingly dense infrastructural sensor stratigraphy in the city. It spans wide-ranging volumetric technologies, from underground seismic and waterflow sensors; through heat, sound and optical street-level monitoring systems; to an assemblage of remote-sensing aerial and satellite-based geographic information systems. However, developed and exclusively controlled and managed by the Chines drone manufacturer DJI1, this geofencing technology 1 serves as a unique example for an emergent mode of blended sovereignty, between the airspace controlled by Israel and the drone flight regulation controlled by DJI.2 Particularly in urban contexts, data infrastructures are becoming increasingly dominant in directing the various layers of everyday life and rapidly shaping technopolitical futures. It can be argued that one of the biggest challenges we face regarding the datafication of cities is the fact that algorithmic infrastructures are opaque and illegible to most of us, therefore very hard to audit and critique. Should we understand these rapid and powerful changes as historical rupture in our understanding of urbanism? Is there space and time for intervention, refusal, and resistance - for “slow urbanism” within the overwhelming acceptance of data-driven smart cities?
This project, Terra Ex-Machina, is a prototype and a critique that addresses these questions as they directly pertain to movement and sensing in the aerial domain. It began with an intuitive question, a curiosity to see how the geofence works in real-time and space, how it effects the ability to see from above. It then continued with a movement between on-theground actions and data interrogation using 3D model space to explore and possibly suggest, ways of seeing that makes this machine-readable digital barrier public.
The first stage of our work was to fly a drone toward the geofence and witness the operation of this digital barrier as it suspends the drone in mid-air. “Crashing” against its perimeter, our drone traversed the threshold of the geofence, its camera lens constantly directed to the epicentre of the restricted zone, the golden dome – Haram al-Sharif. Close to 10000 images taken in sequence during this flight were then processed using structure from motion photogrammetry, the myriad of viewpoints were computationally transcoded into nodal points, triangulated then plotted within virtual three-dimensional space. After weeks of processing, the effect of this data infrastructure of the geofence on conditions of visibility were made visible through our spatial model. Observing it from above, as an orthophoto, we could clearly see a circular outer rim of dense visibility, fading gradually towards a sparse, voided center. The model turns the geofence into a thing in the world, visible and tangible.
In its current iteration we are contrasting the geofence’s top-down technology and the way it prescribes the conditions of visibility by adding layers of balloon and kite aerial photography, that subvert its technological and epistemological standing.
Since the geofence is embedded within drones’ GPS system, it both prescribes and enforces a flight restriction that creates a de-facto gradual ‘draining’ of aerial spatial data from its perimeter towards the centre.3 As such, it is minimizing the multitude of viewpoints that may emerge 3 within this area of protracted conflict at any given time. The point cloud of the no-fly zone exposes a dense visualization of urban space at its rims and sparse, blackened areas of missing data towards its centre. The 3D model is therefore a visualization of the material and epistemic effects of the geofence – it visualizes the geofence as a real-world data infrastructure that changes the urban space by shedding an aerial blackout. The model, however, allows to visualize the real-world effects of this aerial blackout over this part of the city. Indeed, the geofence perimeters encoded into the drone’s navigation system can be hacked or even unlocked temporarily pending approval by DJI, yet even if the fencing is unlocked, flying a drone in Jerusalem is highly restricted and can be risky if done illegally.4 But there is no algorithm (yet) that can ban the flight of a camera tethered to a kite or helium balloon.
Between 2011 and 2016 co-author Hagit Keysar has created do-it-yourself aerial photographs with residents, activists, and researchers in Israel/Palestine, using balloons and kites. Each photographic map embeds situated knowledges and techniques that challenge the aerial “gaze from nowhere” - a myth of a technological, disembodied gaze that is free from human interpretation and bias.
We were using open hardware based on a pocket camera that is lifted into the air by a kite, and an open software to stitch these images together into photographic georectified mosaics. This age-old technique of Kite Aerial photography was developed in the 2010’s as a tool for civic and community science by the open-source community “Public Lab”. It calls for unlearning some of the invisible barriers that inform and construct our ways of seeing, knowing, and living in the world.5 Namely, our understanding of expertise, authority and truth, as well as our relations with technological instruments and images. In each kite or balloon flight, hundreds of images are created but only a dozen or so are chosen for stitching a geo-rectified orthophoto. In creating the 3D photographic model, we reused all the images captured in each of these three cases.
Our efforts to make seen an inherently invisible data infrastructure that can only be observed and experienced by a drone system, have opened unexpected opportunities for audit, critique, and intervention. The drone itself turns into an indispensable research device, without which the virtual turnstile of the geofence cannot be detected. It wasn’t until we reconstructed the restricted space through photogrammetry that we were able to make this technopolitical restriction an actual thing, a discrete object, rather than distributed and dissociated effects in the world. Terra ex-machina is altered by machines for machines, while translating it to human vision and opening to intervention. We suggest that models – as both 3D virtual objects and experimental environments – can serve as augmented sites for making sense of opaque data infrastructures that increasingly restructure urban space. As a prototype, the model is an experimental data infrastructure in itself – it can function as ground for reimagining and speculating on the potential future meanings of urban data infrastructures.
The concluding image shows how the black hole of missing data “blushes” with highly dense visual data retrieved from cameras tethered to balloons and kites, and tightly connected to people on the ground in different places and times. Drawing on Ursula Le Guin’s metaphor of the “carrier bag”, we take terra ex machina as a “carrier bag” that has the capacity to gather and collect, bring together many things that cannot be reduced into one dominant story. The carrier bag collects, preserves, and maintains the multiplicity of life and experience, its contradictions, and frictions. We see this 3D data infrastructure as an opportunity to collect and gather, rather than restrict and unify. Diversifying the data that constructs this virtual terra-ex-machina with multiple and subversive ways of seeing is an attempt to turn the data-gaze on its head by reaffirming the irreducible and recalcitrant nature of human agency.
