Laser for Remote Oil Pollution Detection
Development of the Prototype of the Laser Device for Remote Oil Pollution Detection and Petrochemical Film Thickness Measurement on the Rough Sea Surface
Tech Area / Field
- ENV-MIN/Monitoring and Instrumentation/Environment
- ENV-WPC/Water Pollution and Control/Environment
3 Approved without Funding
MGTU (Moscow State Technical University), Russia, Moscow
- University of Illinois At Urbana-Champaign, USA, IL, Urbana
Project summaryThe proposed project is directed on development and creation of a prototype of a laser equipment (device) for efficient remote detection of oil pollution and petrochemical film thickness measurements on the rough sea surface.
The efficient control of the oil pollution is necessary for an estimation of ecological conditions in inland waters, in harborages, in near-shore zones of the seas, for an estimation of water purification efficiency in waste disposal plants etc.
For today the laser methods on the basis of registration of fluorescent radiation and photometric methods on the basis of laser sources application - one-wavelength (for the task of the detection) and multiwavelength or tunable (for the task of the oil film thickness measurement) are the most promising ones for remote detection of oil pollution and petrochemical film thickness measurement on the water surface from an aircraft.
The laser methods of remote sounding do not require natural illumination, they can be used in a wide range of atmospheric conditions irrespective of time of a day.
The important advantages of the photometric methods are relative simplicity of the equipment (and consequently their low cost). But until recent times disadvantages of the methods were:
- poor reliability of single-spectral measurements for the task of oil pollution;
- necessity of multispectral (using several tens of spectral channels) measurements for the task of petroleum film thickness measurements.
Within the framework of the ISTC project № 2437 “Development of laser methods for remote detection of oil pollution on rough sea surface and measurement of petrochemical product film thickness” in 2004 – 2005 the laser methods for remote detection of oil pollution and petrochemical film thickness measurements on the rough sea surface were developed: the detection method using two sounding wavelengths and petrochemical film thickness measurement methods using two and four sounding wavelengths. The theoretical justification of the suggested methods of measurement for the case of remote measurements and rough sea surface was given. The mathematical modeling of the developed methods operation was conducted.
The proposed project is the extension of this work. The project is directed to the development and creation of prototype of a laser device for detection of oil pollution and petrochemical film thickness measurements on the rough sea surface and its experimental approbation. Operation of the laser device will be based on the methods of detection and measurement of oil film thickness developed within the framework of the project ISTC #2437.
The developed two-spectral laser method of oil pollution detection is based on application of two sounding wavelengths. Application of the two-wavelength laser detection method allows to control two effects simultaneously - wind wave smoothing and variation of sea surface reflection coefficient. It allows to reach the decision on presence of petrochemical pollution with high reliability. In the proposed project it is supposed to use 2,86 μm and 5,76 μm wavelengths for the detection task.
For petrochemical film thickness measurement it is proposed to use the methods of petrochemical film thickness measurement that have been developed within the framework of the project ISTC #2437:
- the two-wave method of petrochemical film thickness d measurement with the thickness from 4 μm to some maximal value dmax. The method is based on determination of transmission coefficient of the oil film (that depends on absorption coefficient of the petrochemical and the film thickness). In the proposed project it is supposed to use 2,86 and 5,76 μm radiation wavelengths. The value dmax depends mainly on used wavelengths and measurement noise. At about 1% mean square relative value of measurement noise the value dmax ~ 140 μm.
- the four-wave method of petrochemical thin film thickness measurement with the thickness from 0,1 to 4 μm. The method is based on determination of phase taper difference in the oil film for sounding wavelengths (that depends on absorption coefficient of the petrochemical and the film thickness). In the proposed project it is supposed to use 1,53; 1,43; 1,406 and 1,33 μm radiation wavelengths.
Mathematical modelling showed a high operation efficiency of the developed methods at selected sounding wavelengths for petrochemical film thickness measurement. The accuracy of oil film thickness measurement in most cases is not worse than 20 % at 1% relative value of measurement mean square error.
Within the framework of the project it is planned to develop block diagram and technical pattern of the laser device, to create a prototype of the device and to conduct laboratory investigations of its operation, to produce an experimental sample of the device suitable for full-scale test, and to conduct the full-scale test of the experimental sample of the device.
The developed compact laser device can be used for both remote measurements of coastal area of the seas (e.g. from an aircraft) and non-contact measurements (e.g. in harborage or in waste disposal plants).
For different applied problems the developed laser device can be used in different modifications, e.g. only for oil pollution detection or for both oil pollution detection and petrochemical thin film thickness measurement with the thickness more than 4 μm (in this case the device will operate on two wavelengths 2,86 and 5,76 μm).
It is proposed that role of the foreign collaborator will consist in information exchange during realization of the project, work meetings by the results of the project performance, performance coordination of the project.
The project is important for realization of the ISTC aim to support applied researches in the field of environment protection.
The head and senior participants of the project are experts in the field of laser sounding of atmosphere and sea surface and development of laser sounding devices.