Enhanced Sidescan-Sonar Image of National Oceanic and Atmospheric Administration (NOAA) Survey H11045, off Bridgeport, Connecticut (H11045_SSSGEO1M_WGS84.TIF, Geographic)

The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. This research program is currently studying sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology. Detailed maps of the sea floor are needed to aid in interpretation of the sea-floor geology. Therefore, sidescan-sonar data have been collected in areas of interest. Although these mosaics from NOAA surveys H11043, H11044, and H11045 in north-central Long Island Sound have been interpreted in prior reports, we have enhanced these three mosaics in order to minimize tonal artifacts created by the mismatching of backscatter in adjacent track lines. The enhanced mosaics provide a clearer image of the sea-floor geology.美国地质调查局（U.S. Geological Survey）联合美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration，NOAA）以及康涅狄格州环境保护部，完成了长岛海湾海底的详细地质制图工作。该研究依托1982年启动的康涅狄格州合作研究项目开展。当前该研究计划正围绕以下内容展开：海底沉积物分布、调控沉积物分布的地质过程、近岸环境相关问题，以及底栖生物群落结构（benthic community structure）与海底地质的关联。 详细的海底制图结果可为海底地质解译提供支撑，因此研究人员在目标海域收集了侧扫声呐（sidescan-sonar）数据。尽管此前的研究报告已对NOAA在长岛海湾中北部开展的H11043、H11044及H11045航次所生成的声呐镶嵌图进行了解译，但本研究对这三幅镶嵌图进行了增强处理，以最大程度消除相邻测线后向散射（backscatter）信号不匹配所产生的色调伪影。经增强处理后的声呐镶嵌图能够更清晰地展现海底地质特征。