Smart Compass-Clinometer: A smartphone application for easy and rapid geological site investigation

This study presents a smartphone application for geological site investigation. The application allows a smartphone to replace a diverse array of instrumentation and processes required for data measurement, visualization, and analysis. This application, named Smart Compass-Clinometer, consists of a digital compass-clinometer module, a data visualization module, a data analysis module, and a data management module. The compass-clinometer module measures the orientation of geological structures using data collected from built-in sensors. It converts the sensor data to orientation information using an algorithm developed specifically for this purpose. The visualization module plots the measured data on stereographic projections using three different methods, and can be used concurrently with the compass-clinometer module. The analysis module conducts instability analyses on the measured data, and can present the results in graphical and statistical forms. Users can send or receive data wirelessly with the data management module, even without a connection to a cellular network. To evaluate and validate the precision and accuracy of the compass-clinometer module, indoor and outdoor tests were conducted using Smart Compass-Clinometer and a conventional compass-clinometer. The minimum standard deviation of measured values with Smart Compass-Clinometer was 0.096° for dip and 0.122° for dip direction. The average difference between values measured using Smart Compass-Clinometer and the conventional compass-clinometer in the outdoor test was 1.70° for dip and 2.63° for dip direction. In an underground mine, the average discrepancies between Smart Compass-Clinometer and the conventional compass-clinometer were 2.57° in dip and 4.57° in dip direction. Smart Compass-Clinometer offers geoscientists a fast, reliable, and convenient tool for geological investigation.