Item

Abstract

Phoenix Geophysics and Metronix are two leading companies offering measurement sys- tems for audio magnetotelluric (MT) measurements. So far data aquired with Phoenix and Metronix systems in use had to be processed separately. While Phoenix provides an implemented data-processing software, data logger from Metronix deliver raw data. Calibration curves of magnetic coils are handed out separately. Processing of data collected with Metronix systems therefore can be done independently and transparently whereas data processing with Phoenix software is non-transparent and data calibration mostly de- pends on their own software. This can pose a problem in areas with strong anthropogenic noise since multi-site processing is limited to the number of devices running simultaneously from each comapny. Thus, a combined processing of Metronix and Phoenix raw data will improve transfer function quality on field surveys using both measurement systems. On a joint MT measurement survey at Kasane (Botswana) of BUIST (Botswana University of Science and Technology) and Goethe University Frankfurt we applied measurement systems ADU07, ADU07e and MTU-5A from Metronix and Phoenix, respectively. Since the town of Kasane is close to the measurement area, the cultural noise production is assumed to be considerable. In order to reduce the noise a multi-site processing is necessary, meaning Phoenix and Metronix data processing has to be executed together. This work shows a method how to calculate calibration curves for MTU raw data. Addi- tionally, we present a new graphical user interface (GUI) implemented to the multivariate processing routine EGstart in Frankfurt MT software FFMT (Hering, 2019), which enables a straight-forward calculation of MTU calibration curves. For future studies, the comparison of Metronix and Phoenix magnetotelluric measurement systems facilitates joint mea- surement campaigns using transparent and independent MT data processing with both measurement systems in the field.