Oil on the Water Characterization with Coherent Fringe Projection and Digital Holographic In-line Interferometry.

摘要

We combine optical methods for sensing of oil films. These are: coherent fringe projection (CFP), digital holographic in-line Interferometry (DHILI). The methods of CFP and DHILI are described as coherent superposition of partial interference patterns. Although there are several methods of remote detection/identification of crude oil in water and/or on the solid surfaces, there is still a need for more efficient and reliable methods [1). Spectroscopic methods allow characterization of oil composition [2] but give little information about spatial distribution of oil. Digital holographic in-line interferometry (DHILI) allows determination oil film thickness [3,4] and size of oil droplets, but requires elaborate image processing. Coherent fringe projection (CFP) techniques proved to be efficient in noncontact metrology of microstructured objects [5]. We suggest combining DHILI and CFP in one set-up for improved detection/identification of oil. We propose a unified approach for modeling of both DHILI and CFP thai is suitable for remote characterization of oil films (spills) in sea water.