Modified Steepest Decent algorithm for ground launch positioning in WGS84 coordinates

In positioning, Gradient Steepest Decent algorithm is used as an iterative method and based on TDOA. This algorithm is designed in the Cartesian coordinates. Given that resources are mainly in the form of latitude and longitude coordinates, Its conversion to Cartesian coordinates is in error. On the other hand, this algorithm requires much number of iterations to convergence towards the desired response, in WGS84 coordinates. In this paper, therewith that the Gradient Steepest Descent algorithm is designed in WGS84 coordinates, performance of this algorithm in terms of error rate and the number of iterations required to achieve the desired accuracy are compared in Cartesian and WGS84 coordinates. Then a way to reduce the iterations and decrease the waste of time is proposed in combination of two coordinates. The root mean square errors of all these methods are compared with each other.