ethermapping

 

In New Zealand's crowded airwaves radio, television, cellphones, microwave links and multiple other wireless communications form an unmarked layer over the landscape. These electromagnetic waves trace paths of shadows and intensities, responding to the shape of the land over which they flow - a kind of 'radio atmosphere' wihin which we live. Ethermapping suggests the density of this atmosphere.

 

Ethermapping is currently being exhibited at ISEA 2006, San Jose, California (August 7-13). It consists of an interactive flash map, and a wall map, representing every radio transmitter in Auckland city, New Zealand, and the transmissions that come from those points. The wall map shows the overlapping zones of transmission that envelop the city. The interactive map allows users to explore these points more closely, representing the extent of transmissions, and the licensing and ownership details of the transmission frequencies.


The maps show the frequencies of every registered radio transmission in the Auckland area, and the physical points from which they originate. In New Zealand, licenses to use most radio frequencies are sold at auction, so that access to radio communications is largely an economic, rather than a social or cultural, matter. This is particularly the case for powerful commercial broadcast and cellular phone frequencies. Ethermapping reveals the pervasiveness and ownership of these intangible resources. The maps use data from the New Zealand Register of Radio Frequencies, found on the website of the Ministry of Economic Development’s Radio Spectrum Management unit. This information is publicly available, but it is very technical and not very visible, so the mapping project transposes the transmission data into a more tangible form.


The transmissions are calculated on the basis of their frequency and the power of the transmitter. Lower frequency, and higher powered, waves propagate further than higher frequency, and lower powered, waves - the extent of the transmissions is represented by the size of the circles. There are many more transmissions than the maps can easily represent, ones that extend beyond the map boundaries, covering the whole region and beyond. The transmissions come from broadcasting, cellular phones, wireless internet, civil defence, maritime safety, ambulance services, and a huge range of licensed communications by industries like construction, transport, oil, and broadcasting. These circles are approximate, ideal-condition calculations of the transmissions based on wavelength and power, imagined as though they exist in perfectly flat landscapes. The calculations can’t account for the design of antennas, and therefore the true shape of transmissions, or for the interaction of the radio waves with the physical geographical environment. In the real world, radio transmissions are affected by the salinity of the land surface, shifting atmospheric conditions, interactions with buildings, hills and valleys, and interference from other transmissions. Ethermapping can only suggest the paths and patterns of this invisible landscape.

The data processing, programming, and design of the interactive map was done by Steve Smith, with database interrogation by David Kabel. The wall map data processing and design was by Igor Drecki and Alan Kwok Lun Cheung.

 

The ethermaps are not yet fully online, but an initial sketch is available [here].

((ethermap.org

 

Ethermapping is being shown at ISEA 2006, alongside Tales from the Ether, which can be found [here]