Mean emission SPL in dB (rms) in search and passive approach flight and mean minimal SPL of active approach during all landings (n = 20 for each dish type).

Mean emission SPL in dB (rms) in search and passive approach flight and mean minimal SPL of active approach during all landings (n = 20 for each dish type).搜索与被动进近飞行阶段的平均发射声压级（SPL，单位为均方根分贝（dB rms）），以及所有着陆过程中主动进近阶段的平均最小声压级（SPL）；每种天线类型的样本量均为n=20。