GPS Sleep
This is a series of GPS tracks recorded when I was asleep to find out where my receiver thought it went during the night.

The GPS was placed just above my pillow on the windowsill.
As I felt I was drifting off to sleep the receiver was switched on, and when I awoke it was switched off.

The universe is being mapped faster and with evermore detail and precision I'm curious to see what can be found in the advances and what is revealed in the limitations.
With the GPS Sleep Zz series I'm intrigued in the inaccuracy of the global positioning system as seen from the various densities of lines and distances between the points.
The positions jump from point to point as the satellite signals are constantly being calculated and updated by the GPS receiver.
The inaccuracies are mostly due to the changing strength of the signals as the receiver looses and acquires direct line of sight with the satellites orbiting the earth.

Another cause of the restlessness of the drawing is that the sky was partially shielded from the GPS receiver by the roof under which I slept.

SLEEP Zz04 Start 10/08/10 01:57:05 Duration 05:34:06 Distance 5.58km Av. Speed 1.1lm/h Max. Speed 24.3km/h

With 1 metre grid

SLEEP Zz03 Start 08/08/10 23:04:31 Duration 09:57:53 Distance 32.66km

GPS Sleep One minute video measuring where my GPS receiver thinks it is as I sleep

SLEEP Zz02 Start 08/08/10 01:12:19 Duration 10:12:19 Distance 6.49km

SLEEP Zz01 Start 07/08/10 02:14:44 Duration 09:07:24

Recorded with a Nokia N86 8MP camera phone with Sports Tracker software.
All drawings are available as limited edition prints upon request from:
The drawings are similar to the Single Line Still series that recorded the GPS time and position of a barbeque, a table, and benches.

jeremy wood 2010