Comparison of L1 and L5 GPS smartphone absolute positioning results

Abstract

Abstract The paper presents the analysis of single-point GPS positioning results obtained from smartphones, using code observations on the L1 and L5 frequencies. In this research we used two Huawei P30 Pro mobile phones and one geodetic receiver (Javad Alpha) acting as the reference receiver. Smartphones were placed at an equal distance of 0.5 m from this receiver. Such a close distance was specially planned by the authors in order to achieve identical observation conditions. Thus, it was possible to compare the accuracy of GPS positioning using pseudoranges on the L1 and L5 frequencies for individual observation epochs. The analysis was carried out from static GPS positioning, using the results from the open-source RTKLib software. In general, the usefulness of code measurements on the L5 frequency to determine the GPS position made it possible to increase the accuracy by several times with respect to the positions determined using the C/A code on the L1 frequency. Average errors of horizontal and vertical coordinates were about 70 % lower for the GPS solution using the L5 code observations than using the L1 code observations. Based on statistical analysis, a horizontal accuracy of about 0.45 m and vertical accuracy of about 1.8 m (STDEV) with only five GPS satellites may be obtained using a smartphone with L5 code observations.