Ethermapping is an ongoing project exploring ways of representing the extent of radio transmissions in Auckland, New Zealand. There are three maps here: two plot all of the transmissions at once, and one is an interactive interface - a Flash based map that locates every radio transmitter in the Auckland region, and the frequencies that are transmitted from them, showing the approximate extent of their transmissions, and some ownership and technical data.

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 [here]. 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 defense, 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.

[Here] is the current interactive version of the ethermap.
The map requires Flash Player 8, which can be downloaded [here].
The database that supports this map is very large, so please be patient with it. 

[This] map shows all of the transmissions in Auckland city at once.

[This] map shows all of auckland's transmissions from a larger scale, showing the edges of transmissions.

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.