Comparison of TEC Estimation Techniques using S1 and L5 Signals of IRNSS
- 94 Downloads
Indian Regional Navigation Satellite System (IRNSS) is a satellite based navigation system developed by Indian Space Research Organization (ISRO). The positional accuracy of IRNSS is limited by several errors including ionospheric delay. Ionospheric delay can be estimated with precise calculation of total electron content (TEC). However, TEC is biased by multipath and thermal noise. Therefore, multipath and thermal noise free relative TEC measurements are made and compared with two other methods, namely, code TEC and IRNSS Receiver Software (IRS) techniques. In this investigation L5 (1176.45 MHz) and S1 (2492.028 MHz) signals from IRNSS 1A to 1G satellites are considered. The results indicate that relative TEC estimation technique removes the multipath and thermal noise from the TEC measurements. Further, the TEC for signals coming from various IRNSS satellites are evaluated by calculating the standard deviation (SD). In the analysis the data is divided into segments with duration of 1 h each. The results indicate that SDs for the relative TEC estimation (2.5 TECU in case of IRNSS 1B) are lesser than the other two techniques indicating the relative TEC can be used in the receiver for the estimation of ionospheric delay. Further, the high ratio of the operating frequencies indicates a better TEC estimation.
Unable to display preview. Download preview PDF.
- 1.Q. J. Mohd, D. S. Achanta, Reddy A. Supraja, T. Sridher, V. K. R. Natam, T. K. Pant, “Multipath and thermal noise free relative TEC estimation using IRNSS L5 and S1 signals,” Proc. of Int. Conf. on Innovative Technologies in Engineering, ICITE-2018, 11–13 Apr. 2018, Hyderabad, India (2018).Google Scholar
- 3.K. Yedukondalu, A. D. Sarma, S. S. Vemuri, “Estimation and mitigation of GPS multipath interference using adaptive filtering,” PIER M 21, 133 (2011). DOI: 10.2528/PIERM11080811.Google Scholar
- 4.R. B. Langley, “GPS receiver system noise,” GPS World, 40 (June 1997).Google Scholar
- 6.T. Walter, K. Gunning, J. Blanch, “Improved ephemeris monitoring for GNSS,” Proc. of ION Int. Tech. Meeting, 25–28 (Jan. 2016).Google Scholar
- 7.V. G. Rao, G. Lachepelle, “Proposed dual frequency signal design for optimal TTFF in IRNSS,” Proc. of Pearl Jubilee Int. Conf. on Navigation and Communication, 20–21 Dec. 2012, Hyderabad, India (2012).Google Scholar
- 9.“IRNSS signal in space ICD for standard positioning service,” v. 1.0, June 2014, ISROIRNSS-ICD-SPS-1.0, Indian Space Research Organization (ISRO), Bangalore.Google Scholar
- 10.C. Carrano, K. Groves, “Ionospheric data processing and analysis,” Proc. of Workshop on Satellite Navigation Science and Technology for Africa, March 23–April 9, 2009, The Abdus Salam ICTP, Trieste, Italy (2009).Google Scholar