High-spectral-resolution lidar for ocean ecosystem studies

摘要

The research and protection of the ocean ecosystem are key works to maintain the marine status and develop marine functions. However, human's knowledge about the ocean is greatly limited. Now, in situ, acoustic and remote sensing methods have been applied in the research to understand and explore the ocean. Especially, the lidar is one outstanding remote sensing method for its high spatial and temporal resolution as well as the ability of the vertical detection. High-spectral-resolution lidar (HSRL) employs an ultra-narrow spectral filter to distinguish scattering signals between particles and water molecules without assuming a lidar ratio and obtains optical properties of the ocean with a high accuracy. Nevertheless, the complexity of the seawater causes variable marine optical properties, which gives huge potentiality to develop a HSRL working at different wavelengths in order to promote the inversion accuracy and increase the detection depth. The field-widened Michelson interferometer (FWMI), whose central transmittance can be tuned to any wavelength and field of view is large, can be employed as the HSRL spectral filter and solves problems that the operating wavelength of the iodine filter is fixed and the field of view of Fabry-Perot interferometer is small. The principle of the HSRL based on the FWMI designing for the ocean remote sensing will be presented in detail, hi addition, the availability of the application of the FWMI influenced by the disturbance of the states of Brillouin scattering is analyzed and the preliminary theory shows that the HSRL instrument basing on FWMI could be employed in the marine remote sensing with a high accuracy.