Offshore oil slicks are significant for both the monitoring of marine spill accidents and the detection of marine oil resources.The use of remote sensing technology to detect the thickness of oil slicks is a major are...Offshore oil slicks are significant for both the monitoring of marine spill accidents and the detection of marine oil resources.The use of remote sensing technology to detect the thickness of oil slicks is a major area of research.The reflected light from oil slicks changes with the thickness of the oil.This is the theoretical basis of research on optical remote sensing of offshore oil slicks.A two-beam interference model that considers the offshore oil slick as a flat plate has been developed in this study.A quantitative remote sensing model which describes a series of processes that use oil slick thickness and reflectance as variables is established.The use of the Fresnel equation to analyze parameters in the model indicated that the key property of the quantitative relationship between the oil slick thickness and reflectance was ultimately the disappearance or extinction of the oil slick.This model has been tested and verified by data from offshore oil slick spectral response experiments.Results showed that the oil slick thickness remote sensing model can be theoretically analyzed and is efficient.The research indicated that the major cause of variations in the spectral response as a function of oil slick thickness was the different light-scattering characteristics.These characteristics can be used in remote sensing applications to identify the different types of offshore oil slicks.The theoretical interpretation of each parameter in this model led to the development of a look-up table of the model parameters which will improve the efficiency of future offshore oil slick remote sensing.展开更多
Using the seawater taken from Liaodong Bay and crude oil taken from Liaohe Oilfield,a laboratory experiment was designed to study the change of reflectance spectrum of artificial offshore oil slick with its thickness ...Using the seawater taken from Liaodong Bay and crude oil taken from Liaohe Oilfield,a laboratory experiment was designed to study the change of reflectance spectrum of artificial offshore oil slick with its thickness and to identify the spectrum ranges suitable for quantifying the thickness of the oil slick.During the experiment,crude oil was continuously dropped into the seawater to generate artificial oil slick with different thicknesses.After every drop of crude oil was added,reflectance spectrum of the oil slick was measured with a high resolution spectroradiometer(ASD FieldSpec Pro FR).The influence of oil slick thickness on its reflectance spectrum was explored through statistical analysis.The results show that the reflectance of oil slick changes marginally with oil slick thickness and higher than that of seawater in infrared band from 1150 to 2500 nm.This spectrum range can be practically used to distinguish oil slick from seawater.In the spectrum range from 400 to 1150 nm,the reflectance of oil slick decreases with its thickness.The negative power function is the best-fit function expressing the relationship between the reflectance and thickness.The spectral characteristics of oil slick are very distinct at 550 and 645 nm.They are the best wavelengths for monitoring the existence of offshore oil slick and estimating its thickness.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 40971186 and 41001196 )the Open Research Fund of Key Laboratory of Digital Earth,Center for Earth Observation and Digital Earth,Chinese Academy of Sciences (Grant No. 2010LDE007)
文摘Offshore oil slicks are significant for both the monitoring of marine spill accidents and the detection of marine oil resources.The use of remote sensing technology to detect the thickness of oil slicks is a major area of research.The reflected light from oil slicks changes with the thickness of the oil.This is the theoretical basis of research on optical remote sensing of offshore oil slicks.A two-beam interference model that considers the offshore oil slick as a flat plate has been developed in this study.A quantitative remote sensing model which describes a series of processes that use oil slick thickness and reflectance as variables is established.The use of the Fresnel equation to analyze parameters in the model indicated that the key property of the quantitative relationship between the oil slick thickness and reflectance was ultimately the disappearance or extinction of the oil slick.This model has been tested and verified by data from offshore oil slick spectral response experiments.Results showed that the oil slick thickness remote sensing model can be theoretically analyzed and is efficient.The research indicated that the major cause of variations in the spectral response as a function of oil slick thickness was the different light-scattering characteristics.These characteristics can be used in remote sensing applications to identify the different types of offshore oil slicks.The theoretical interpretation of each parameter in this model led to the development of a look-up table of the model parameters which will improve the efficiency of future offshore oil slick remote sensing.
基金Supported by PetroChina Exploration and Development Research Institute (Grant No.06-01C-01-08)
文摘Using the seawater taken from Liaodong Bay and crude oil taken from Liaohe Oilfield,a laboratory experiment was designed to study the change of reflectance spectrum of artificial offshore oil slick with its thickness and to identify the spectrum ranges suitable for quantifying the thickness of the oil slick.During the experiment,crude oil was continuously dropped into the seawater to generate artificial oil slick with different thicknesses.After every drop of crude oil was added,reflectance spectrum of the oil slick was measured with a high resolution spectroradiometer(ASD FieldSpec Pro FR).The influence of oil slick thickness on its reflectance spectrum was explored through statistical analysis.The results show that the reflectance of oil slick changes marginally with oil slick thickness and higher than that of seawater in infrared band from 1150 to 2500 nm.This spectrum range can be practically used to distinguish oil slick from seawater.In the spectrum range from 400 to 1150 nm,the reflectance of oil slick decreases with its thickness.The negative power function is the best-fit function expressing the relationship between the reflectance and thickness.The spectral characteristics of oil slick are very distinct at 550 and 645 nm.They are the best wavelengths for monitoring the existence of offshore oil slick and estimating its thickness.
