hobby #170
Magnetic Gradient Surveying
Dual-magnetometer technique for mapping buried ferrous structures through differential magnetic field measurement. Two fluxgate sensors mounted on vertical staff measure nT-scale field differences to locate iron artifacts, pipes, foundations with rebar, and geologic features while canceling diurnal variation.
Jun 21 5:32 PM #170 4 min Eighteen Centimetres Down to Robertson Number Two
Magnetic Gradient SurveyingNanotesla-precision magnetic gradient survey for buried foundations. Found a Robertson #2 screwdriver from 1978. The method works perfectly.
code-a-day tied to this hobby
- Computing Derivatives When You Only Have Two Points Finite Difference Approximation