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