  Cosmic rays have valuable information about universe surroundings us. Finding
energy, mass and arrival direction of primary cosmic ray particle are the most
important aspects of extensive air shower studies. In order to determine these
parameters, arrival direction and core position of extensive air showers should
be determined at first. In this article, a new method has been introduced that
utilizes arrival time information of secondary particles of extensive air
showers for finding their core location and correcting plane wave front
approximation so that calculate the arrival direction of extensive air showers.
This method does not need number sensitive detectors-detectors which are
sensitive to the number of crossing particles- and consequently there is no
need for lateral distribution models. This model has been developed by analysis
of simulated events generated by CORSIKA package.
