This paper reveals about global navigation satellite system GNSS in the indian subcontinent known as the navigation in the indian subcontinent(NavIC) We have tried to model a new technique in GNSS known as the optical flow tracking global navigation system (OF GNSS). This method using differential equations is very accurate for very small distances on the surface of the earth in the 1500km range of the Indian subcontinent satellite coverage. When we talk of accuracy of the GPS system it should be very accurate on the surface of the earth when used to show changes in coordinate of the moving body with respect to the ground by the satellite which is situated on the earths orbit. Optical flow is a method which uses movements with respect to x and y axis for infinitesimal changes in its coordinates and then uses this algorithm to use it in global positioning system to find accurate position of the body with respect to the satellite coordinates with respect to ground positioning. The modern method of differential frames is also very accurate as it involves infinitesimal frames which are modelled together from the satellite to find changes in the coordinates on the earths surface, so we have designed a new algorithm in this paper on the Optical flow GNSS system which is an alternative and can improve the study done in the design of these algorithms in this field of applications.