FutureSpace Talk 15 | Mia Bennett

The Spectral Turn of Satellites

Abstract

Over time, humans have been able to distinguish and capture finer portions of the electromagnetic spectrum at increasing resolutions. Modern optical sensors can resolve the Earth in detailed color at resolutions of up to 10 centimeters. This type of passive remote sensing mimic human vision by recording spectral information, or light. Yet another technique which does not measure spectral information, synthetic aperture radar (SAR), is increasingly used in military, commercial, and scientific contexts. SAR satellites shoot microwave pulses of energy, which penetrate through clouds and darkness, at the Earth’s surface, and measure the electrical signal, or “backscatter,” which returns. This information allows interpretation of surface properties, structure, and motion regardless of the weather or time of day. Unlike optical data, SAR data therefore allows continuous monitoring. Yet though often visualized as an image, SAR data does not lend itself well to orthodox spatial intuition understanding, and its interpretation requires technical skills. Theorizing the cultural and epistemic consequences of SAR necessitates transcending visual critiques of remote sensing, which have largely considered optical satellite imagery. Herein, we review SAR technology and offer a more-than-visual critique of its data to problematize how it makes sense of the world – and the haptic, shadowy world it is setting into motion, particularly in conflict settings. We also draw attention to the difficulties laypeople face in interpreting SAR imagery, which may make the data harder to interrogate for all but specialists. Should SAR increasingly to inform decision-making, this may challenge accountability and transparency in democracies.

Bio

Mia Bennett is an associate professor in the Department of Geography at the University of Washington and is visiting the UCL Department of Anthropology until March with the support of a British Academy Visiting Fellowship. As a political geographer with geospatial skills, she researches cultures and practices of frontier-making in the Arctic and orbital space. Bennett’s methods combine fieldwork and critical remote sensing, a subfield whose development she is helping to lead, which promotes both critical use and critique of satellite imagery. Since 2009, she has run a blog on the Arctic called Cryopolitics. Bennett received a PhD in Geography from UCLA and an MPhil in Polar Studies from the University of Cambridge. Previously, she taught at the University of Hong Kong. Her new book co-authored with Klaus Dodds, Unfrozen: The Fight for the Future of the Arctic, was published by Yale University Press last month.