Complementary research ability of ground- and space-based detectors of ultra high energy cosmic rays

In comparison of ground- and space-based optical detectors of ultra high energy cosmic rays (UHECR) the space-based detectors have the advantage of registering EAS, initiated by UHECR particles, at a much larger area of the atmosphere. They also have the advantages of observing EAS in a wide range of atmosphere depth including near-horizontal EAS, initiated by neutrino. at depths >1000 g cm(-2). Ground-based particle detector arrays have the advantages of taking data on EAS parameters, sensitive to a primary particle mass, not determined by space detectors. Particle. detectors having 100% duty cycle observe a specific UHECR source longer than the space detector with the same geometrical factor.