Peculiar velocities distort the correlation function of galaxies in redshift space. In the linear regime, the distortion has a characteristic quadrupole plus hexadecapole form. The amplitude of the distortion depends on the cosmological density parameter-OMEGA. Practical formulae are derived here which can be applied to redshift galaxy catalogs to measure-OMEGA in the linear regime. The formulae also yield the real underlying correlation function in the linear regime, corrected for peculiar velocities.