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

Authors

  • 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

DOI:

https://doi.org/10.13052/jgeu0975-1416.923

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 litera-
ture 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 propa-
gation 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, iono-
spheric 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 & Devel-
opment 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 Appli-
cation Area, with the Indian Space Research Organization (ISRO), India.
His research interests include propagation modeling in the ionosphere and
troposphere and NavIC applications.

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Published

2021-06-09

How to Cite

Bhardwaj, S. C., Vidyarthi, A., Jassal, B. S., & Shukla, A. K. (2021). Estimation and Assessment of Ionospheric Slant Total Electron Content (STEC) Using Dual-frequency NavIC Satellite System. Journal of Graphic Era University, 9(2), 137–156. https://doi.org/10.13052/jgeu0975-1416.923

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