Backscatter ionospheric sounding (BIS) is a powerful tool for monitoring and predicting conditions of operation of HF communication systems. The BIS method is adopted to determine coverage areas of radio waves and maximum usable radio frequencies, distance along the ground to a scatterer, as well as to gain information about ionospheric structure and conditions. To solve these problems, we propose a method for direct diagnostics of HF radio channel at the leading edge of BIS signals on ionograms. The method relies on real-time automatic processing and interpretation of BIS ionograms. We present algorithms for determining the maximum usable frequencies and characteristics of oblique sounding signals from current BIS data, without correcting ionospheric parameters. We realize the algorithm for recovering ionospheric parameters at the path midpoint.