We present an approach to the characterization of low-power bright picosecond optical pulses with an internal frequency modulation simultaneously in both time and frequency domains in practically much used case of the Gaussian shape. This approach exploits the Wigner time–frequency distribution, which can be found for these bright pulses by using a novel interferometric technique under our proposal. Then, the simplest two-beam scanning Michelson interferometer is selected for shaping the field-strength auto-correlation function of low-power picosecond pulse trains. We are proposing and considering in principle the key features of a new experimental technique for accurate and reliable measurements of the train-average width as well as the value and sign of the frequency chirp of pulses in high-repetition-rate trains. This technique is founded on an ingenious algorithm for the advanced metrology, assumes using a specially designed supplementary semiconductor cell, and suggests carrying out a pair of additional measures with exploiting this semiconductor cell. Such a procedure makes possible constructing the Wigner distribution and describing the above-listed time–frequency parameters of low-power bright picosecond optical pulses. In the appendix, we follow one of possible avenues for deriving the joint Wigner time–frequency distribution via choosing the Weil’s correspondence between classical functions and operators.