Estimation and Visualization of 3D orbits of GPS satellites using GPS navigation data file and SP3 data file

this paper is to find the orbital path of the 32 GPS satellites revolving around the earth in elliptical path in ECEF coordinate system. The process of Trilateration finds position of user, velocity and time of the user, where we use three satellites to identify user location anywhere on globe. To find the orbital path of GPS satellite we extracted some parameters from GPS navigation data file and compared with RINEX File. These parameters are then implemented in formulas by using MATLAB and XYZ coordinates in ECEF system are obtained and a 2 Dimensional plot. Another 2 Dimensional plot of XYZ coordinates are obtained from SP3 file. The variance is calculated by comparing the 2D plot of GPS satellite obtained from GPS navigation data file and SP3 file. This variance calculated indicates the amount of error present in GPS satellite path. This 2 Dimensional plot obtained by SP3 file is converted into 3 Dimensional plot in ECEF coordinate system. The 3 Dimension plot is plotted with equator as reference and poles as the reference.