In tracing the genealogy of information visualization there are a number of potential historical discourses to draw from. The study of information design usually employs statistics, demographics or cartography as choice vantage points from which to consider the discipline. A continued interest in the work of William Playfair (1759-1823) and Charles Minard (1781-1870) is proof positive of the legitimacy of these backstories in the eyes of most design historians.

One of the most famous images associated with Charles Minard is his temporal map (pictured above) which details the ill-fated march of Napoleon into Russia in 1812-1813. It is no accident that one of the first complex information graphics schematized a military campaign, considering the longstanding tradition of technological and informational innovation being spurned by the gears of war. This particular cartographic enterprise has become of of the signature images of information visualization and can often be found within the first several slides of any introductory presentation on the topic. However, instead of submerging into a detailed analysis of the techniques and methodology of Minard in this visualization, a more fruitful discussion would be to instead dwell on the fact that this image was produced to document and represent a military campaign. Given that technological innovation is implicit in warfare, it only follows that the military is a key area of interest to any historical analysis of information visualization.

Of the many battles that took place between the United Kingdom and Germany during WWII, the Battle of the Beams was one of the most decisive. This conflict pitted nascent British and German radar technology against one another with aerial dominance of the skies over England hanging in the balance.

Radar was first developed by the German inventor Christian Huelsmeyer for the purpose of collision avoidance in nautical navigation. Huelsmeyer publicly demonstrated his system in 1904 and it operated by firing radio waves at targets and detecting their reflections. Over the next two decades, European and North American scientists would further develop this research and the range of radar systems extended from several to 25 miles. By the onset of the war, radar was emerging as a viable tactical tool. The crux of British-German radar warfare emerged from the German air force’s utilization of the Knickebein and X-Gerät signal transmission systems to enable nighttime bombing runs over Britain. The Luftwaffe bombing raids were executed with surgical precision and this presented a sea change in aerial warfare to which the British military had to respond. Fortunately for Britain, a rudimentary radar network had been implemented before the onset of the war and it was able to serve as the cornerstone in a comprehensive British defense strategy that would ultimately “out-visualize” their German opponents.

In 1937, a prototype radar network was set up along the perimeters of Great Britain. Dubbed Chain Home, the system consisted of a line of transmitter stations positioned at 50 mile intervals around the perimeter of the United Kingdom. Led by scientist Robert Watson-Watt the British military capitalized on this system to develop state-of-the-art methods for enemy detection and fire control. This advanced mapping of the airspace over the United Kingdom acted as a force-multiplier allowing the British defenses to concentrate the aircraft where they were needed most and coordinate supporting anti-aircraft fire. Chain Home was monitored by oscilloscope display units and the operation of this system is described in wikipedia as follows:

When a pulse was sent out into the broadcast towers, the scope was triggered to start its beam moving horizontally across the screen very rapidly. The output from the receiver was amplified and fed into the vertical axis of the scope, so a return from an aircraft would deflect the beam upward. This formed a spike on the display, and the distance from the left side — measured with a small scale on the bottom of the screen — would give the distance to the target. By rotating the receiver goniometer [a tool for measuring angles] connected to the antennas to make the display disappear, the operator could determine the direction to the target… while the size of the vertical displacement indicated something of the number of aircraft involved. By comparing the strengths returned from the various antennas up the tower, the altitude could be determined.

This imaging technology provided the British forces with an early warning system by generating realtime data tracking German aerial activity over, or approaching, the United Kingdom. These types of radar-based defense networks have been described as “electromagnetic curtains”, an upgrade to the medieval notion of fortification in which brick and mortar are bolstered and extended by telecommunication infrastructure (see Manuel de Landa’s War in the Age of Intelligent Machines for an excellent critical reading of the history of the technology).

Parallel to the development of radar, British military engineers also implemented identification, friend or foe (IFF), which utilized an early version of RFID technology to distinguish friendly from "other" aircraft on a radar display. This kind of "tagging" and related RFID technology (along with the ubiquitous database) is now a driving force of contemporary inventory management.

The technological developments outlined above provided Britain with the strategic edge it required to turn the tide in the air war against Germany. Oscilloscope based radar system would eventually give way to the Plan Position Indicator (PPI) display (pictured above in a contemporary meteorological context), which is now universally associated with radar technology.

This post originally appeared on Serial Consign. View it here.