In adaptive high-frequency (HF) radio, the overall process by which measurements of signal quality are made, assessed, and analyzed. Note 1: In LQA, signal quality is determined by measuring, assessing, and analyzing link parameters, such as bit error ratio (BER,) and the levels of the ratio of signal-plus-noise-plus-distortion to noise-plus-distortion (SINAD. ) Measurements are stored at--and exchanged between--stations, for use in making decisions about link establishment. Note 2: For adaptive HF radio, LQA is automatically performed and is usually based on analyses of pseudo-BERs and SINAD readings.