(1)EM122开机问题,经过最近两个航次的使用,发现EM122 TRU的电源HV必须启动两次才能正常。
(2)EM122采用船底刚朵拉方式安装,因此航行一段时间后会挂上很多绳子,渔网等等,由于声学设备特别是EM122都位于刚朵拉底部,所以会造成多波束的噪声增多,水体图像上的表现为,浅层水体不干净,噪声很多。
通过自检,可以看出:
RX NOISE SPECTRUM
Board No: 1 2 3 4
10.0 kHz: 64.2 64.7 65.9 68.0 dB
10.2 kHz: 65.6 66.5 67.6 69.7 dB
10.3 kHz: 66.8 67.7 68.5 70.9 dB
10.4 kHz: 67.1 67.7 69.7 71.4 dB
10.6 kHz: 67.3 67.4 70.1 71.7 dB
10.7 kHz: 68.4 67.3 70.4 70.8 dB
10.9 kHz: 69.2 67.1 69.8 71.7 dB
11.0 kHz: 69.1 67.4 70.6 72.5 dB
11.2 kHz: 69.9 67.6 70.6 72.3 dB
11.3 kHz: 69.7 67.8 70.3 72.0 dB
11.4 kHz: 69.4 67.1 71.9 72.3 dB
11.6 kHz: 69.2 66.5 71.4 71.4 dB
11.7 kHz: 69.4 65.1 72.2 71.6 dB
11.9 kHz: 70.2 66.6 72.4 72.3 dB
12.0 kHz: 69.9 65.6 71.6 73.2 dB
12.1 kHz: 70.0 65.2 71.1 72.2 dB
12.3 kHz: 69.6 65.8 70.4 72.0 dB
12.4 kHz: 69.8 64.6 70.8 72.0 dB
12.6 kHz: 69.3 64.4 70.8 72.3 dB
12.7 kHz: 68.0 65.2 70.2 71.9 dB
12.9 kHz: 67.2 65.8 70.1 71.3 dB
13.0 kHz: 66.1 66.3 69.0 71.1 dB
Maximum noise at Board 4 Frequency 12.0 kHz Level: 73.2 dB
噪声平均为71~72db
靠港请潜水员进行清理以后,造成水平降低,自检看出:
RX NOISE SPECTRUM
Board No: 1 2 3 4
10.0 kHz: 52.2 57.1 51.2 58.0 dB
10.2 kHz: 53.1 59.7 51.4 57.9 dB
10.3 kHz: 54.6 60.5 51.6 59.3 dB
10.4 kHz: 56.1 60.4 53.0 59.3 dB
10.6 kHz: 55.9 61.2 52.7 58.9 dB
10.7 kHz: 57.7 62.5 52.4 59.6 dB
10.9 kHz: 58.9 62.9 52.6 61.3 dB
11.0 kHz: 59.5 63.4 53.1 59.7 dB
11.2 kHz: 60.4 65.9 52.9 59.1 dB
11.3 kHz: 61.8 65.6 54.0 60.1 dB
11.4 kHz: 62.4 64.4 53.7 60.9 dB
11.6 kHz: 60.5 65.7 53.4 62.2 dB
11.7 kHz: 58.3 66.6 53.4 61.5 dB
11.9 kHz: 57.6 63.5 54.1 61.2 dB
12.0 kHz: 57.2 63.8 53.1 62.1 dB
12.1 kHz: 57.1 64.3 52.4 61.1 dB
12.3 kHz: 57.2 64.1 53.2 60.6 dB
12.4 kHz: 57.0 63.3 53.9 60.0 dB
12.6 kHz: 57.6 64.1 54.2 60.1 dB
12.7 kHz: 58.0 64.1 54.3 59.7 dB
12.9 kHz: 57.5 62.6 55.1 58.2 dB
13.0 kHz: 57.3 60.3 55.7 58.1 dB
Maximum noise at Board 2 Frequency 11.7 kHz Level: 66.6 dB
噪声平均为59~60db,水体图像如下,浅层水体非常干净。
(3)EM122浪高2.5m(包含涌浪的时候)的图像:
下图是一次海浪和涌浪增大时,多波束多次找不到海底,不得不调整最大发射角度,增强回波信号强度,调整最大发射角以后,多波束就很快找到底了,说明信号发射正常,而且从水体可以看出浅层水体非常干净,完全是回波信号强度的问题。