The linear-scanned-array wavefront sensor extends the applicability of imaging centroid trackers to Hartmann-type outgoing wave beam-control systems. Oscillating mirrors are used to produce optical integration of the irradiance distribution along one axis while the centroid is measured along the orthogonal axis. The use of linear detector arrays reduces the total detector-element count and increases the measurement bandwidth in comparison to area array sensors. Experiments with a four-beam laboratory model of the sensor have demonstrated centroiding of 150-pm diameter Hartmann spots to an accuracy of better than 0.6 µm at 4-kHz bandwidth. Optimal thresholding can improve the measurement accuracy considerably. The linearity of the sensor was measured to be better than 0.2 pm over an 80-pm range.