Diagrams

  1. Fig. 1
  2. Fig. 2
  3. Fig. 3
  4. Fig. 4
  5. Fig. 5
  6. Fig. 6
  7. Fig. 7

GPS satellite orbit at 20,200km altitude

Four satellites per orbit at 30˚, 105˚, 120˚ and 105˚ from the previous satellite

Each successive orbital plane angled at 55˚ inclination and 60˚ right ascension

Complete constellation of six orbital planes completed December 1993

Projection of the GPS constellation within the six orbital planes

Separations of the six orbital groups of four satellites

Six projections of the GPS signal system, creating irregular stellated icositetrahedrons

You Are Here

James Bridle

The Global Positioning System was first articulated in 1973, at a meeting of 12 military officers at the Pentagon. They proposed a constellation of satellites around the Earth which could be used to triangulate a position with extraordinary accuracy at any point on its surface. The proposal built on previous navigation systems, notably the Decca chains of master and slave ground stations, which provided guidance to a generation of marine navigators through the proven principle of phase difference analysis. Each satellite would continuously send out a time and position signal, and each receiver would be able to infer, from the differences between these signals, its own position.

GPS was originally intended as a secure military system, but on 1st September 1983, Korean Air Lines Flight 007, carrying 269 people, was shot down by a Soviet interceptor, having strayed into the USSR’s airspace, and in the aftermath Ronald Reagan issued a direct order to make the nascent GPS freely available for civilian use, as a common good.

The GPS satellites circle the earth twice a day, at an altitude of 20,200 kilometres, one of the highest orbital bands, moving at 7,000 kilometres per hour. The initial plan called for 24 satellites in six angled orbits. The final satellite of this first configuration was manoeuvred into place in December 1993, completely covering the whole planet, at all times. A further six satellites have been added in eccentric orbits since that date, but this marks the completion of a vast structure, a celestial superstructure that we are all living inside.

To ask “Where You Are” invites a series of responses: cartographic, historical, social, spiritual, situational; discursive or prescriptive. The GPS system is a monumental network that provides a permanent “You Are Here” sign hanging in the sky, its signal a constant, synchronised timecode. It suggests the possibility that one may never need be lost again; that future generations will grow up not knowing what it means to be truly lost.

It also stands for all the networked technologies we build around us to support life, culture, and civilisation: the networks of telephony, data, communication and transport that encircle the earth, dive beneath the oceans and are strung on poles and highways across continents, radically transforming perceptions of geography. Mapping these perceived geographies warps traditional notions of flat or spherical space – and must include us, too. The GPS system is part of what Deleuze and Guattari termed the “abstract machine”, the sum of all machines which in their terminology includes the body, society, language, interpretation and technology. So the network too is one of these abstract machines: a mainframe, a terminal, a handheld device, a wireless LAN, a diadem of satellites, and us.

Mapping is a process of understanding: in order to be able to act fully and decisively in the world, we must render it legible, because only by reading the world are we capable of writing into it. Maps are powerful; they gift those who commission, draw and understand them a greater agency than those who operate in ignorance of the true shape of the terrain. As that terrain extends into the virtual, the electromagnetic, the invisible, so cartography must work to illuminate these dimensions as well.

These diagrams are an attempt to model the enfolding super-structure of the GPS system at the point of its first incarnation, in 1993. Twenty-four satellites Fig. 4, 5, in six orbital groups of four satellites Fig. 2, 6, each orbital plane at 55 degrees inclination, and 60 degrees right ascension to its neighbour Fig. 3, 20,200 kilometres above the surface of the earth Fig.1. The intersecting cones of their influence form a 24-pointed star Fig. 7– an irregular stellated icositetrahedron – a grand asymmetric architecture composed of space-hardened signallers and radio waves, and us, no longer lost, suspended in its ever-shifting embrace.