Smoothing Smartphone GPS Raw Measurements


This research aims to investigate the smoothing of the pseudo-range raw measurements of the smartphone using a Hatch filter. The measurements of smartphones suffer from high noise generated from low-cost antennas and oscillators, which are designed to work in a certain way. These types of low-cost antennas and oscillators are entirely different from geodetic instruments, which are designed for high accuracy positioning. The GPS measurement data were collected using a Huawei P10 device, 41 minutes and 24 seconds GPS observation time with sampling intervals of 1 second using Geo++ Android application. The GPS measurements are processed using standalone (epoch by epoch) method, by MATLAB software developed by the authors, as a part of a software package for processing smartphone GPS measurements. The errors in raw measurements in the Easting, Northing, and Up (ENU) components when using standalone (epoch by epoch) method are ranging from -50m to 30m, and the errors after applying the Hatch filter are reduced to have ranged from -10m to 5m, the raw data were very noisy and funded it has many cycles slips as a result of low-cost antennas and oscillators of smartphone’s. The cycle slips in the measurements were detected and found that it was the result of jumping the errors to 27 m in northing and 43 m in up