If you can't go to the Anomaly then let the Anomaly come to you - Rubens Cage Surveys

We use small-scale surveys in a three-axis, uniform field generating coil set (a Rubens cage) to emulate the Black Hill Norite magnetic field anomaly in South Australia. We then run further surveys with the source rotated to provide a vertical magnetization and in a vertical applied field to investigate the FFT reduction-to-pole (RTP) transform, which for this anomaly faces challenges arising from the low-inclination magnetization. Survey-based data imperfections are an important influence on performance of the RTP transform and this study provides a valuable extension of computer-based investigations. We show that striations in the RTP anomalies of both the measured and emulated BHN anomalies are due to FFT artefacts avoided in physical rotation of the magnetization to the vertical.