The classification of the methods of measuring information redundancy reduction in the telemetry systems and its comparative analysis are performed. The aperture methods are established to be the most suitable for the data redundancy compression techniques in the reduction of the measuring information in the telemetry systems. New aspects of the compression algorithm in the aperture method are developed on the basis of Taylor polynomials (extrapolation) and Lagrange polynomials (interpolation). The combined method — linear extrapolation on the transmitting side and the interpolation on the receiving side — is proposed to be used in the aperture approaches for data redundancy reduction. The combined approach is characterized by the absence of delay and a simpler algorithm realization on the transmitting side.