The possibility of inducing population gratings in a three-level resonant medium using a pair of unipolar attosecond pulses that do not overlap in the medium has been studied theoretically. It has been shown that the results of the approximate solution of the Schrodinger equation agree with the results of the numerical solution of the system of equations for the density matrix of a three-level medium whose parameters are close to the parameters of atomic vapors of rubidium.