...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>ICES Journal of Marine Science >Improving acoustic estimates of krill: experience from repeat sampling of northern krill (Meganyctiphanes norvegica) in Gullmarsfjord, Sweden
【24h】

Improving acoustic estimates of krill: experience from repeat sampling of northern krill (Meganyctiphanes norvegica) in Gullmarsfjord, Sweden

机译：改善磷虾的声学估计：在瑞典古马斯峡湾对北磷虾（Meganyctiphanes norvegica）进行重复采样的经验

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A series of eight replicated acoustic surveys, four by day and four by night, was undertaken in Gullmarsfjord on the Swedish west coast during two 24-h periods on 8 and 10 September 2003, using a calibrated echosounder operating at 120 and 38 kHz. The difference in signal strength (ΔS_V) was used to distinguish northern krill (Meganyctiphanes norvegica) from other acoustic scatterers. The approach is concluded to be very effective, but it can be improved greatly by applying the following series of simple extensions to current protocols: first, set a very low threshold on both frequencies to minimize sampling bias; second, undertake tests to confirm that the data extracted from each acoustic frequency apply to the same scatterers; third, ensure that the range of ΔS_V is not greater than the TS_(range) at either frequency; and finally, when abundance estimation is the primary aim, arrange for sampling at the time of day and using the acoustic frequency that together provide the least variance.
机译：2003年9月8日至10日，在瑞典西海岸的Gullmarsfjord进行了八次重复的声波测量，分别在120 kHz和38 kHz下进行了两次八小时的连续两次，时间为两个24小时。信号强度的差异（ΔS_V）用于区分北磷虾（Meganyctiphanes norvegica）与其他声散射体。该方法被认为是非常有效的，但是可以通过对当前协议应用以下一系列简单扩展来大大改进该方法：首先，在两个频率上都设置一个非常低的阈值，以最大程度地减少采样偏差；第二，进行测试以确认从每个声频提取的数据适用于相同的散射体；第三，在任一频率下，确保ΔS_V的范围不大于TS_（范围）。最后，当丰度估算为主要目标时，请安排在一天中的某个时间进行采样，并使用共同提供最小方差的声频。

著录项

相似文献

  • 外文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号