• GPS satellite and receiver instrumental biases estimation using least squares method for accurate ionosphere modelling

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      https://www.ias.ac.in/article/fulltext/jess/116/05/0407-0411

    • Keywords

       

      Instrumental biases; Global Positioning System; GPS Aided Geo Augmented Navigation; Space-Based Augmentation System.

    • Abstract

       

      The positional accuracy of the Global Positioning System (GPS)is limited due to several error sources.The major error is ionosphere.By augmenting the GPS,the Category I (CAT I)Precision Approach (PA)requirements can be achieved.The Space-Based Augmentation System (SBAS)in India is known as GPS Aided Geo Augmented Navigation (GAGAN).One of the prominent errors in GAGAN that limits the positional accuracy is instrumental biases.Calibration of these biases is particularly important in achieving the CAT I PA landings.In this paper,a new algorithm is proposed to estimate the instrumental biases by modelling the TEC using 4th order polynomial.The algorithm uses values corresponding to a single station for one month period and the results confirm the validity of the algorithm.The experimental results indicate that the estimation precision of the satellite-plus-receiver instrumental bias is of the order of ± 0.17 nsec.The observed mean bias error is of the order − 3.638 nsec and − 4.71 nsec for satellite 1 and 31 respectively.It is found that results are consistent over the period.

    • Author Affiliations

       

      G Sasibhushana Rao1

      1. University College of Engineering, Andhra University, Visakhapatnam 530 003, India.
    • Dates

       
  • Journal of Earth System Science | News

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