The optical interferometry systems are widely used for surface metrology. However, the environmental noise and the data analysis approach can limit the measurement performance during in- process inspection. This paper introduces a wavelength scanning interferometer (WSI) for micro and nano-scale areal surface measurement. The WSI can measure large discontinuous surface profiles without phase ambiguity problems. The proposed WSI is immune to environmental noise using an active servo control system that serves as a phase compensating mechanism. Furthermore, a parallel CUDA programming model is presented as a solution to accelerate the computing analysis. The presented system can be used for on-line or in-process measurement on the shop floor.