HEPL Seminar

Thursday 8 September 2005, 4.15 pm
(Refreshments available at 4pm)
Location AP200

Ulrich Schreiber
Forschungseinrichtung Satellitengeodäsie, TU-München,
Fundamentalstation Wettzell, Germany

“High Precision Sagnac Interferometry for Applications in Geoscience ”

Characteristic parameters such as sensitivity, scaling factor stability and instrumental drift are usually used to qualify rotational sensors in navigation. In this group of sensors, ring lasers may be considered as one of the most successful representatives. The sensitivity to rotation improves significantly as the size of such instruments is scaled up. However this also results in much higher demands on mechanical stability of large ring laser gyroscopes. In our laboratories in Germany and New Zealand we have constructed and operated more than 6 ring lasers with effective areas between 1 and 800 m 2 realized in various different ways. With respect to stability and sensitivity some of these sensors exceed the performance of tpyical navigational ring laser gyros by several orders of magnitude.

Contributions from solid Earth tides, microseismics, teleseismic events as well as high frequency components of the nutation of the rotational axis of the Earth (known as diurnal polar motion) can now readily be observed with these instruments. This talk outlines the current status of large ring laser gyros and new fields of application.

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rev 2 Sep 2005 NC