Field Survey Methodology in
Low-Frequency Signal Analysis
3.2 Site procedure. Measurements at the primary survey site were recorded over eleven consecutive days at fixed intervals. Baseline drift was corrected against a reference receiver placed four kilometres inland. Readings outside two standard deviations were logged, reviewed and, where attributable to local interference, excluded from the working set.
Ambient conditions were stable throughout. Instrument calibration followed standard field procedure6. One recurring pattern did not conform to any known local source and has not been included in the analysis that follows7.
3.3 Limitations. The present study concerns method, not interpretation. Survey coordinates are provided in Appendix A for replication.
6 Calibration logs are available from the authors on request.
7 A persistent signal anomaly was detected at the primary survey site. The anomaly falls outside the scope of this study and will be documented separately.