Document Type : Research Paper
Authors
1 Civil Engineering, University of Technology - Iraq
2 Department of Civil Engineering, University of Technology - Iraq
Abstract
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.
Keywords
Main Subjects
Controlled-Environment Quality Assessment of
Android GNSS Raw Measurements,” Electronics, vol.
8, no.1, p. 5, 2019.
[2] E. D. Kaplan and C. Hegarty, “Understanding
GPS/GNSS: Principles and Applications,” Artech
House, Third Edition, 2017.
[3] P. Misra and P. Enge, “Global Positioning
System: signals, measurements and performance,”
Ganga-Jamuna Press, Second edition, Massachusetts,
2006.
[4] B. Park, C. Lim, Y. Yun, E. Kim, and C. J. S.
Kee, “Optimal divergence-free Hatch filter for GNSS
single-frequency measurement,” Sensors, vol. 17, no.
3, p. 448, 2017.
[5] J. Guo, J. Ou, Y. Yuan, and H. J. P. i. N. S.
Wang, “Optimal carrier-smoothed-code algorithm for
dual-frequency GPS data,” Progress in Natural
Science: Materials International, vol. 18, no. 5, pp.
591-594, 2008.
[6] G. Xu, and Y. Xu, “GPS: theory, algorithms and
applications,” Springer, 2016.
[7] R. Hatch, “The synergism of GPS code and
carrier measurements,” International Geodetic
Symposium on Satellite Doppler Positioning,
Washington, DC, pp. 1213-1231, 1983.
[8] Z. Dai, “MATLAB software for GPS cycle-slip
processing,” GPS solutions, vol. 16, pp. 267-272,
2012.
)
