Analysis of the effect of magnetotelluric data quality improvement using rho variance and edit XPR parameters in densely populated areas

Magnetotelluric (MT) research was conducted to map the fault structure in the western part of East Java. The advantage of the magnetotelluric method is its deep penetration because it propagates at a low frequency so that it can detect resistivity anomalies that are thought to be faults. The measuring path of the magnetotelluric method covered the Surabaya and Gresik areas. Research conducted in densely populated areas thus it requires a noise reduction process to improve the quality of the data. Performing the robust processing with Rho Variance parameters and editing XPR is an effort to reduce noise and to improve the quality of magnetotelluric data. The robust processing result of 5 (five) sounding MT data using the Rho Variance parameter can improve the quality of magnetotelluric data by increasing the coherence value of 2.128% (MT01), 2.804% (MT02), 2.378% (MT03), 3.508% (MT04), and 3.129% (MT12). Meanwhile, the editing XPR process can increase the coherence value of 0.184% (MT01), 7.155% (MT02), 9,364% (MT03), 0.784% (MT04), and 0.628% (MT12). Escalation of coherence value by implemented the Rho Variance and Editing XPR means that two methods are sufficient effectively to raise the confidence level of MT data processing and interpretation result.