These ideas were still very fresh in 1996 when Army ERDEC requested a monitoring system to track and correct velocity errors in any FT-IR spectrometer. The multi-channel DSP approach outlined here was suggested as the natural implementation of the synchronized sampling proposed in 1994. Over time the remaining pieces fell into place. A method to extract the transfer functions of the detector elements and electronics was needed, hardware and software were needed for digitizing both the laser and infrared signals, and some new signal processing approaches were needed to improve computational efficiency. First light emitting diodes (LED's) had to be tested to find ones fast enough for characterizing the detectors and circuits in typical spectrometers. Finally, convenient methods to measure and disturb the velocity were needed. It was considered undesirable to use large vibration test equipment for this purpose.