[Review Article] Recent Techniques in Surface Metrology

An overview of the recent techniques used in surface metrology is presented. The techniques used in surface metrology can be classified into two: the first is contact measuring systems and the other is non-contact measuring systems. We start with explanation of the contact and non-contact measuring systems with their merits and demerits in surface metrology. Since the non-contact measuring systems have many advantages in surface metrology, so we proceed by focusing on the non-contact measuring systems and their recent technology. Then we proceed with explanation of the most common methods attached with the non-contact measuring systems used to extract the surface of the object being measured in three dimensional (3D). Recent techniques such as a rotating diffuser and convolution of Chebyshev type 2 and elliptic filters, proposed by the author, are explained in detail to enhance the measurement in surface metrology. Finally, we present some of potential applications in surface metrology such as measurement of steep smooth surfaces, rough surfaces, and opaque surfaces. The selected applications illustrate the major merits of using the non-contact measuring systems: it is possible to measure a relatively large field of view with high precision and in real-time. We end with an overview about estimation of the uncertainty budget in non-contact measuring systems.