  The South Pole Acoustic Test Setup (SPATS) was built to evaluate the acoustic
characteristics of the South Pole ice in the 10 kHz to 100 kHz frequency range,
for the purpose of assessing the feasibility of an acoustic neutrino detection
array at the South Pole. The SPATS hardware consists of four vertical strings
deployed in the upper 500 m of the South Pole ice cap. The strings form a
trapezoidal array with a maximum baseline of 543 m. Each string has 7 stages
equipped with one transmitter and one sensor module. Sound is detected or
generated by piezoelectric ceramic elements inside the modules. Analogue
signals are sent to the surface on electric cables where they are digitized by
a PC-based data acquisition system. The data from all strings are collected on
a central computer in the IceCube Laboratory from where they are send to a
central data storage facility via a satellite link or stored locally on tape. A
technical overview of SPATS and its performance is presented.
