Methodological and Experimental Investigation of a Gravimetric Prospecting Technique Based on the Combined Exploitation of Smartphone Inertial Sensors

Gravimetric surveying is widely used to detect subsurface density contrasts and to identify buried cavities and geological structures. Conventional gravimeters provide high precision but remain costly and complex. This study investigates a low-cost alternative based on the inertial sensors of a smartphone (iPhone 7), combining a tri-axial accelerometer and a gyroscope to estimate the local gravitational acceleration. The proposed method consists of performing repeated acceleration measurements, calibrating the sensors, correcting the device orientation through sensor fusion, and extracting the static component of gravity. Experiments were conducted under three configurations to evaluate repeatability and measurement precision. Processed data show standard deviations on the order of 10^？6, indicating good stability and reproducibility. These results demonstrate the feasibility of a portable and affordable gravimetric approach suitable for experimental and educational applications. Further validation against reference gravimeters is required to assess the metrological performance for geophysical exploration purposes.