Cascading De-noising Algorithm for Improving GPS Positional Accuracy
The temporal and spectral variations of GPS errors severely degrade the precise positioning. These errors may change the positional information from centimeters to several meters and may result catastrophic errors in navigational information of civil aviation. Applying of de-noising methods by targeting both temporal and spectral features of GPS errors is a new strategy. With conventional code carrier smoothing algorithms, the maximum amount of temporal variations is eliminated, and by novel wavelet multiresolution analysis, the other systematic and random errors of GPS are eliminated. In present research, a combination of code carrier smoothing algorithm and wavelet multiresolution analysis is used to improve the GPS receiver position smoothing. The proposed method is well suited for critical application like GAGAN of Indian SBAS augmentation for improving positional accuracy. In this analysis, the raw GPS data is firstly processed with traditional code carrier smoothing to remove the temporal variations before position is estimated. Subsequently, the Wavelet Hidden Markov Tree (WHMT) is used to reduce the systematic and random biases of GPS.
KeywordsGlobal positioning system (GPS) Hatch filter Multiresolution analysis Wavelet hidden markov model (WHMT)
The author Ch Mahesh, expresses sincere thanks to the team of Nav-Aid, Hyderabad International Airport limited, Hyderabad and S. Nandulal, Asst. GM (CNS), GAGAN, AAI, for their continuous support and valuable suggestions of this project.
- 1.Misra, P., Enge, P.: Global Positioning System (GPS), Signals, Measurements and Performance. Ganga-Jamuna Press, P.O.Box-633, Lincoln, MA 01773. ISBN:0-9709544-1-7Google Scholar
- 2.Fu, W.X., Rizos, C.: The applications of wavelets to GPS signal processings. In: 10th Intl. Tech. Meeting of the Satellite Division of the U.S Inst. of Navigation, Kansas City, Missouri, pp. 1385-1388, 16–19 Sept 1997Google Scholar
- 3.Satirpod, C., Ogeja, C., Wang, J., Rizos, C.: An approach to GPS analysis incorporating wavelet decomposition. Artif. Satell. 36, 27–25 (2001)Google Scholar
- 4.Rife, J., Tufts University, Sen, S., Tufts University: Design of a Single-Frequency Filter that Minimizes Ionosphere Divergence ErrorGoogle Scholar
- 6.Adhika Pradipta Lie, A.: Hatch Filter: Single and Dual—Frequency Carrier Smoothing. (2006)Google Scholar
- 7.Sunehra, Dhiraj: Validation of GPS receiver instrumental biases results for precise navigation. Indian J. Radio Space Phys. 42, 175–181 (2013)Google Scholar
- 8.Hwang, P., McGraw, G., Bader, J.: Enhanced differential GPS carrier-smoothed code processing using dual-frequency measurements. Navigation 46(2), 127–137 (1999)Google Scholar
- 10.Romberg, J.K., Choi, H., Baraniuk, R.G.: Bayesian tree—structured image modeling using wavelet–domain hidden markov models. In: Proceedings of SPIE, Denvor, CO, vol. 3816, pp. 31–44, July 1999Google Scholar