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Abstract

Magnetotellurics is a so called passive method where natural electromagnetic variations are used as signal excitation. The convenience of passive methods works at the expense of signal - to - noise ratios which are generally poor due to the absence of control of signal strengths. The Remote -Reference -Technique is an effective way to improve magnetotelluric data quality by referencing the local fields to simultaneously recorded and undisturbed fields at a remote reference site. In areas where noise level is high remote reference processing is required but finding and maintaining a reference site during a campaign is expensive and time consuming. Therefore a permanent and self - sustaining reference station simplifies MT measurements which are carried out in a radius where source fields are still coherent, which depends on the frequency. For high frequencies up to 1000Hz this coherency radius can amount to over 800 km, which was proven by referencing data from the Black Forest to Rügen (Schill et al., 2011). Locating appropriate reference sites across Germany was not an easy task. We found high quality data in the urban forest of Wittstock where the permanent reference station was installed end of 2011. Reference data is being permanently recorded with sampling rates up to several kilohertz since 2010. Meantime the Wittstock station operated repeatedly as reference and magnetotelluric data from northern and eastern Germany could significantly be improved. Access to the reference site data is open to the MT community.