ABSTRACT
The study of extensive air showers (EAS) using ground arrays of scintillation counters is the oldest technique in the field. The idea is to determine the approximate lateral distribution function of an EAS by sampling the charged particle component at the earth's surface. The area of the array detectors and their spacing determines the size threshold and is an important parameter in determining the angular resolution of the array. The measurement of zenith angle usually assumes that the EAS shower front near the axis is planar, and that the time spread of the shower front is small. The Haverah Park ground array was constructed using water tanks instead of scintillation counter to detect ground level particles from EAS. The Yakutsk array although formally similar to the Haverah Park array, has several unique features. The array uses scintillation counters, Cherenkov light detectors, and muon detectors to simultaneously measure some lateral distribution functions.
