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渤海是我国的半封闭内海,受陆源影响显著,水体光学性质复杂多变,静止轨道水色卫星(GOCI)的高时间分辨率数据为研究渤海水体总吸收系数的时空变化特征,特别是逐时变化提供了可能。针对GOCI波段设置,利用实测数据建立了基于遥感反射率波段比值的412、443、555 nm波段渤海总吸收系数遥感反演模型,经独立实测数据检验,模型反演值与实测值的相关系数大于0.8,平均相对误差(APD)小于13%,中值相对误差小于9%,优于已有典型算法(精度提高约10%);经独立现场-卫星时空匹配数据检验,基于该模型和GOCI卫星数据的总吸收系数遥感反演平均相对误差在35%以内。基于2015年5月4日1天8景的GOCI影像和所建立的模型,研究了渤海总吸收系数的逐时变化特征。结果表明,8:30—15:30期间总吸收系数变幅主要分布范围是0.2~0.3 m~(-1),最大变幅可达到0.8 m~(-1),变幅极大值主要分布在辽东湾、渤海湾和莱州湾近岸海域。结合潮汐数据的分析发现,辽东湾、渤海湾北部总吸收系数与潮高的逐时变化具有较好的一致性,总吸收系数极小值出现时刻滞后于低潮时刻0~1.5 h;莱州湾西部总吸收系数与潮高逐时变化呈明显负相关性;渤海湾南部、莱州湾东部总吸收系数与潮高变化未见显著相关性。
Bohai Sea is a semi-enclosed inland sea in China. Due to the significant influence of terrestrial sources, the complex and variable optical properties of water bodies, the high temporal resolution data of the geolocular satellite (GOCI) is the temporal and spatial variation of the total absorption coefficient of the Bohai Sea, Provided possible. According to the GOCI band setting, the remote sensing inversion model of the total absorption coefficient of the Bohai Sea based on remote sensing reflectance band ratio was established based on remote sensing reflectance band ratio. The independent measured data show that the correlation coefficient between the model inversion value and the measured value is greater than 0.8, the average relative error (APD) is less than 13%, and the median relative error is less than 9%, which is better than the typical algorithm (about 10% accuracy improvement); based on the independent site- satellite space- The data of the total absorption coefficient of the remote sensing inversion average relative error within 35%. Based on the GOCI images and the established model of one day and eight scenes on May 4, 2015, the hourly variation of the total absorption coefficient in the Bohai Sea was studied. The results showed that the main range of variation of total absorption coefficient was 0.2 ~ 0.3 m ~ (-1) during the period of 8:30 to 15:30, and the maximum amplitude was 0.8 m ~ (-1). The main distribution of maximum amplitude In Liaodong Bay, Bohai Bay and Laizhou Bay coastal waters. According to the analysis of tidal data, it is found that there is a good consistency between the total absorption coefficient and the tide height in Liaodong Bay and northern Bohai Bay. The minimum value of total absorption coefficient lags behind 0-1.5 h at low tide; in the west of Laizhou Bay There was a negative correlation between the total absorption coefficient and the tidal height and hourly variation. There was no significant correlation between the total absorption coefficient and the tide height in the southern Bohai Bay and the eastern part of Laizhou Bay.