Description
An acoustic echo-location system was applied for distant localization of
the Baikal Neutrino Telescope string positions. The echo-location system
was situated on the ice surface, while the telescope stayed in its standard
arrangement between 1100 and 1200 m depth. "Large" reflectors, such as the
end buoys located above the strings, served as reference marks. Acoustic
localization of these marks was conducted by means of antenna comprising
four acoustic projectors spaced with 50 meters from each other and placed
under the ice on the depth of 9.5 m. Acoustic pulses occupied the frequency
band between 10 and 22 kHz and had the length of 51.2 s. In result of
tomographying, all three large objects (two double buoys and the central
electronics module) were localized and visualized as evident (contrast)
spots. Localization accuracy represented the value of app. 0.2 m (range
lengthwise) and app. 1.0 m (range crosswise), which was fully acceptable
for current purposes. There also have been made estimations for signal
forms and parameters necessary for improved acoustic tomography
measurements of the telescope.
Auteurs principaux
Konstantin Kebkal
(EvoLogics GmbH, Berlin)
Ralf Wischnewski
(Institut for Nuclear Research, Moscow)
