Real-time time drift adjustment for a TDR step stimulus

A method for reducing drift in a step stimulus from a sampling system, such as an oscilloscope, is described having an initial step of setting a calibration repetition rate. A step stimulus stabilization calibration is performed to acquire a reference mid-crossing time and the current mid-crossing time. Acquisition cycles of TDR/TDT waveform samples are acquired equal to the repetition rate with the initial strobe delay interval in the sampling system being adjusted by the difference between the reference mid-crossing time and the current mid-crossing time. The step stimulus stabilization calibration is performed again to acquire a new current mid-crossing time and initial strobe delay interval and more acquisition cycles of TDR waveform samples are acquired equal to the repetition rate. The process continues until a stop command is activated for the sampling system.