Estimation and Assessment of Ionospheric Slant Total Electron Content (STEC) Using Dual-frequency NavIC Satellite System

  • Sharat chandra Bhardwaj Propagation Research Laboratory, Department of Electronics and Communication, Graphic Era (Deemed to be) University, Dehradun, India
  • Anurag Vidyarthi Propagation Research Laboratory, Department of Electronics and Communication, Graphic Era (Deemed to be) University, Dehradun, India
  • B. S. Jassal Propagation Research Laboratory, Department of Electronics and Communication, Graphic Era (Deemed to be) University, Dehradun, India
  • Ashish K. Shukla Space Applications Center, Indian Space Research Organization, Ahmedabad, India
Keywords: Code range, Carrier range, NavIC, STEC, Data Pre-processing, Ionospheric delay

Abstract

Many atmospheric errors affect the positional accuracy of a satellite-based navigation device, such as troposphere, ionosphere, multipath, and so on, but the ionosphere is the most significant contributor to positional error. Since the ionosphere’s dynamics are highly complex, especially in low latitude and equatorial regions, a dual-frequency approach for calculating slant total electron content (STEC) for ionospheric delay estimation performs better in these conditions. However, the STEC is ambiguous and it cannot be used directly for ionospheric delay prediction, accurate positioning purposes, or ionospheric study. As a result, STEC estimation and pre-processing are required steps prior to any positioning application. There is very little literature available for STEC pre-processing in the NavIC system, necessitating an in-depth discussion. This paper focuses on how to extract navigational data from a raw binary file obtained from the Indian NavIC satellites, estimate and pre-process STEC, and build a database for STEC. It has been found that an hourly averaged STEC data is suitable for ionospheric studies and monthly mean value can be used for ionospheric behavioral research. Furthermore, the STEC is affected by diurnal solar activity, thus, the seven-month data analysis that includes summer and winter months has been used to study ionosphere action during the summer and winter months. It has been observed that STEC values are higher during the summer months than the winter months; some seasonal characteristics are also been found.

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Author Biographies

Sharat chandra Bhardwaj, Propagation Research Laboratory, Department of Electronics and Communication, Graphic Era (Deemed to be) University, Dehradun, India

Sharat Chandra Bhardwaj is Ph.D. student at the Graphic Era (deemed to be University), Dehradun India. He received B.E. and M.Tech. degree in electronics and communication from Sant Longowal Institute of Engineering and Technology, Longowal, Punjab, India, in 2009 and 2011 respectively. He is currently a Research Fellow working with the Indian Space Research Organization, Ahmedabad, India. His area of interest includes signal propagation through the ionosphere.

Anurag Vidyarthi, Propagation Research Laboratory, Department of Electronics and Communication, Graphic Era (Deemed to be) University, Dehradun, India

Anurag Vidyarthi received B.Sc. degree from MJPR University, Bareilly, India, in 2005 and M.Sc. degree from BU Bhopal, India, in 2007. He receives M.Tech. and Ph.D. degree from Graphic Era University, India, in 2010 and 2014 respectively. Presently he is associated with Department of Electronics and Communication Engineering, Graphic Era University, Dehradun, India. His areas of interest are rain attenuation, fade mitigation techniques, ionospheric effects on the navigation system, and applications of Navigational satellite data.

B. S. Jassal, Propagation Research Laboratory, Department of Electronics and Communication, Graphic Era (Deemed to be) University, Dehradun, India

B. S. Jassal received M.Sc. degree in Physics from Meerut University, Meerut, India, in 1968 and Ph.D. degree in Science (Radiowave propagation) from Jadavpur University, Calcutta, India, in 1990. He worked as lecturer in DAV (PG) College, Dehradun from July 1969 to October 1969. He worked in Defence Electronics Applications Laboratory (Defence Research & Development Organization, Govt. of India) as a scientist for 38 years from 1969 to 2007. He headed various research projects relating to RF and Microwave communication, Radiometric studies of the atmosphere, terminal guidance systems, satellite communication for military applications. Presently he is associated with Graphic Era University, Dehradun since 2008. In addition to teaching undergraduate and postgraduate students, he has also been involved in various sponsored research projects. His present area of research is NavIC system based ionospheric studies.

Ashish K. Shukla, Space Applications Center, Indian Space Research Organization, Ahmedabad, India

Ashish K. Shukla received the Masters and Ph.D. degrees in applied mathematics from Lucknow University, Lucknow, India, in 1997 and 2003 respectively. He is currently a scientist in the SATCOM and IT Application Area, with the Indian Space Research Organization (ISRO), India. His research interests include propagation modeling in the ionosphere and troposphere and NavIC applications.

References

Bhardwaj, S. C., Vidyarthi, A., Jassal, B. S., and Shukla, A. K. (2020). Estimation of Temporal Variability of Differential Instrumental Biases of NavIC Satellites and Receiver using Kalman Filter. Radio Science. https://doi.org/10.1029/2019RS006886

Bhardwaj, S. C., Vidyarthi, A., Jassal, B. S., and Shukla, A. K. (2020). Investigation of ionospheric total electron content (tec) during summer months for ionosphere modeling in Indian region using dual-frequency NavIC system. Advances in Intelligent Systems and Computing, 1166, 83–91. https://doi.org/10.1007/978-981-15-5148-2_8

Bhardwaj, S. C., Vidyarthi, A., Jassal, B. S., and Shukla, A. K. (2018). Study of temporal variation of vertical TEC using NavIC data. 2017 International Conference on Emerging Trends in Computing and Communication Technologies, ICETCCT 2017, 2018-January, 1–5. https://doi.org/10.1109/ICETCCT.2017.8280317

Bradford W. Parkinson (Stanford University, Stanford, C. ), and James J. Spilker Jr. (Stanford Telecom, Sunnyvale, C. (2013). Global Positioning System: Theory and Applications (Vol. 53, Issue 9). https://doi.org/10.1017/CBO9781107415324.004

Coster, A. J., Gaposchkin, E. M., and Thornton, L. E. (1992). Real-Time Ionospheric Monitoring System Using GPS. Navigation, 39(2), 191–204. https://doi.org/10.1002/j.2161-4296.1992.tb01874.x

Hager, B. H., King, R. W., and Murray, M. H. (1991). System Global Positioning.

Hernández-Pajares, M., Juan, J. M., Sanz, J., Aragón-Àngel, À., García-Rigo, A., Salazar, D., and Escudero, M. (2011). The ionosphere: Effects, GPS modeling and the benefits for space geodetic techniques. Journal of Geodesy, 85(12), 887–907. https://doi.org/10.1007/s00190-011-0508-5

IRNSS Signal-in-Space ICD for SPS Version 1.0 Signal in Space ICD for Standard Positioning Service Configuration Definition Document Satellite Navigation Programme. (2017).

Jakowski, N., Mayer, C., Hoque, M. M., and Wilken, V. (2011). Total electron content models and their use in ionosphere monitoring. Radio Science, 46(5), 1–11. https://doi.org/10.1029/2010RS004620

Jin, S., and Jin, R. (2011). GPS Ionospheric Mapping and Tomography: A Case of Study in a Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China Graduate University of the Chinese Academy of Sciences, Beijing 100049, China. 1127–1130. http://nssdcftp.gsfc.nasa.gov/models/ionospheric/iri/iri2007

Klobuchar, J. A. (1987). Ionospheric Time-Delay Algorithm for Single-Frequency GPS Users. IEEE Transactions on Aerospace and Electronic Systems, AES-23(3), 325–331. https://doi.org/10.1109/TAES.1987.310829

Li, J., and Jin, S. (2016). Second-order ionospheric effects on ionospheric electron density estimation from GPS Radio Occultation. International Geoscience and Remote Sensing Symposium (IGARSS), 2016-Novem, 3952–3955. https://doi.org/10.1109/IGARSS.2016.7730027

Ma, X., Tang, C., and Wang, X. (2019). The evaluation of IRNSS/NavIC system’s performance in its primary and secondary service areas–data quality, usability and single point positioning. Acta Geodaetica et Geophysica, 54(1), 55–70. https://doi.org/10.1007/s40328-019-00246-8

Mannucci, A. J., Wilson, B. D., Yuan, D. N., Ho, C. H., Lindqwister, U. J., and Runge, T. F. (1998). A global mapping technique for GPS-derived ionospheric total electron content measurements. Radio Science, 33(3), 565–582. https://doi.org/10.1029/97RS02707

Of Geophysics, A., and To, S. (2004). 8 Effects of gradients of the electron density on Earth-space communications (Vol. 47, Issue 3).

Ratnam, D. V., Dabbakuti, J. R. K. K., and Sunda, S. (2017). Modeling of Ionospheric Time Delays Based on a Multishell Spherical Harmonics Function Approach. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10(12), 5784–5790. https://doi.org/10.1109/JSTARS.2017.2743695

Sinha, S., Mathur, R., Bharadwaj, S. C., Vidyarthi, A., Jassal, B. S., and Shukla, A. K. (2018, December 1). Estimation and smoothing of tec from navic dual frequency data. 2018 4th International Conference on Computing Communication and Automation, ICCCA 2018. https://doi.org/10.1109/CCAA.2018.8777665

Suryanarayana Rao, K. N. (2007). GAGAN – The Indian satellite based augmentation system. Indian Journal of Radio and Space Physics, 36(4).

Zhong, J., Lei, J., Dou, X., and Yue, X. (2016). Assessment of vertical TEC mapping functions for space-based GNSS observations. GPS Solutions, 20(3), 353–362. https://doi.org/10.1007/s10291-015-0444-6

Published
2021-07-04
Section
Articles