Digital optical method (DOM™) and system for determining opacity

US7495767B2 · kind B2 · utility

Assignee

• The United States of America as represented by the Secretary of the Army · US

Inventors

• Byung Joo Kim · Incheon, KR
• Mark J. Rood · Champaign, US
• Ke Du · Tangxia, CN

Key dates

• Filing date: Apr 20, 2006
• Grant date: Feb 24, 2009
• Expiry date: Mar 24, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/5957
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Photography is employed to objectively quantify opacity of fluids such as smoke plumes and dust via a method termed the Digital Optical Method (DOM™). The DOM™ quantifies the ratio of radiance values by means of a camera response curve obtained using objective measures. The radiance ratios are then used to calculate opacity of target fluids such as smoke plumes. The DOM™ quantifies opacity during both daytime and nighttime conditions with a much broader range of subject types, e.g., white, gray and black smoke plumes, and environmental conditions, e.g., non-blue-sky, building, and mountain backgrounds, than existing systems while not requiring human interpretation for any application. In one embodiment, the DOM™ quantifies opacity from digital photos using a pre-designed algorithm and an inexpensive digital camera. Very little training is needed to implement the DOM™ and it yields consistent objective quantitative results, while providing a permanent photographic record easily digitally archived.