Assessing Jitter in Sensor Time Series from Android Mobile Devices

This paper is motivated by work on a real-time Android navigation system using accelerometer, gyroscope, and camera data. We observed that our attempts at combining data from these different sensors yielded time series with jitter, i.e., inaccurate timestamps, that negatively affected program correctness and reliability. Thus, the aim of this paper is to help Android developers anticipate, assess, and understand problems with data quality in sensor-dependent applications. Our analysis focuses on jitter in timestamps obtained from Android's SensorManager and CameraManager services. We demonstrate the presence and severity of jitter obtained through these services and explain the characteristics of Android that originate jitter, resulting in a taxonomy of the various sources of jitter. Finally, we discuss the results of a quantitative analysis of jitter performed on three Android mobile devices (HTC One M8, Google Nexus 5, and Asus Zenfone 2) and provide recommendations on how Android developers can design sensing applications that will behave correctly across the majority of mobile devices.