Using Smartphones as a Measurement Platform in Geoscience Applications

Abstract

Most modern smartphones come with a variety of sensors. Among them are the gyroscope, accelerometer, magnetometer, GNSS (Global Navigation Satellite Systems) receiver, and from 2020, most modern devices are also coupled with a Lidar (Light Detection and Ranging) sensor. These specific sensors allow to acquire data that enables the location and spatial orientation of the smartphone in relation to other objects, and also measure them. For this, it is important to understand how the principle of operation of these sensors occurs, as well as the respective raw data obtained and how to use these data from the sensors to get measurements of the elements of the physical surface of the Earth. This article aims to present a state of the art about the working principle of these sensors and presents the raw data from them. In addition, this article seeks to present an initial test on the quality of the orientation sensor, based on the comparison between the data obtained from this sensor and a total station with high angular precision (1 second). It was noted the occurrence of a systematic error in the observations of the horizontal directions, and an average discrepancy of 5.20° between the observations of the vertical angle. The use of sensors attached to smartphones can support in several activities of geoscience application, such as carrying out a prior survey of a given area of study, aiming to do a pre-analysis of geodetic networks, to carry out measurements of angles and distances for applications in terrain measurements, or even to assist the Geographic Information System (GIS) development.