---
# System prepended metadata

title: NTFI研究筆記
tags: [NTFI]

---

# NTFI研究筆記

* key points 
    * let them know that Ao is important
    * let them thoroughly understand AO as they may not be familiar with this topic
    * eff. digit
    * 到時候檔案會很大
    * 實驗基本部分：儀器、地點、實驗時間、一堆照片
    ==GPS 25.1445299, 121.8050581==

* PSD發現的特殊時段(我們從PSD找到的異常)
    * 日落日出的兩根黃色（溫度跟光度跟潮汐）
    * 日夜大規模的比較（各頻率、各能量）
    * 18:00~19:30 anomaly（鰕虎、雀鯛跟低頻槍蝦的互動）：2.7kHz低、300Hz高（播放槍蝦snapping Shrimp跟鰕虎goby 的聲音），以及其他在八點左右之後的相似patterns
    * 04:00(船嚇跑了槍蝦和魚，播船的聲音)
    * 船的活動18:51 00:18、潛水客或其他原因(小尺度，播潛水客的聲音)
==簡報'https://hackmd.io/@hchs-earthscience/r15Ish8n5'==
#   **NEW!!!!!!!**[ppt編輯連結](https://1drv.ms/p/s!AiPxlN1a7YpOhnXyUPmEvwkE9mB0)

###    濾波計畫
1. 全天剪頻率-> 0~1200Hz
2. 取21:30 無人聲純自然聲音做背景降噪音->失敗
3. 取18:54 ->失敗
4. 取21:30做魚跟背景聲音移除->半成功 
5. 取人聲音做聲音移除？
## P50圖發現的奇特現象
 ![](https://i.imgur.com/FT0e8tU.png)
 ![](https://i.imgur.com/ybuHaJI.png)

### anomalies in time
#### valleys
1. 1839.42(lum<21.6)~1909, 2.2~3.8kHz, low amplitude median 55dB (超明顯) 
==A:有種槍蝦是peak ~3kHz, ~20dB，在這段時間內此中槍蝦活動力高，製造較多分貝較低的聲音，占比高導致中位數降低==
~~==A:槍蝦在吃東西，所以沒有空繼續捕捉==~~
![](https://i.imgur.com/eXgpU9d.png)

![](https://i.imgur.com/6WGuMzr.png)
valley~ 2500Hz
![](https://i.imgur.com/IKd6yeq.png)
![](https://i.imgur.com/mmBlDiE.png)

![](https://i.imgur.com/zFjJg2y.png)




3. 1954~2015 & 2024~2033 & 2052 & 2106 & 2115 & 2127~2233  all frequency (boats)
1957 1:20秒 蝦虎 ~170Hz
2kHz的中位數有明顯的下降。
![](https://i.imgur.com/r6OcS19.png)

5. 0015~0324 all fre (slight) (boats？？？) 
==0018.40~0019.20 boat confirmed==


![](https://i.imgur.com/2D4QNw7.png)
![](https://i.imgur.com/QGv2XIp.png)
0340-0343 船(明顯低頻分貝增加，已確定不是魚的聲音)
![](https://i.imgur.com/USDURSb.png)



6. 0357 all fre 黃轉藍 (超明顯) 
==A:被船嚇跑、被干擾==
7. 0815 all fre (超明顯)頻譜圖呈現40kHz脈衝訊號
8. 0812~0815 船
![](https://i.imgur.com/bZFVUYr.png)
8. 0848 船和潛水客(潛水客呼氣頻率約為10次一分鐘)
![](https://i.imgur.com/MawtByd.png)

8. 0945 >31kHz

##### peaks
1. 1840~1912 >11kHz(超明顯)
2. 18:51 <300Hz 雀鯛 
    想法：蝦虎魚和槍蝦是共生關係，當時低頻聲音變大聲，可能是因為雀鯛活動力上升(繁殖季求偶)，而蝦虎魚和雀鯛是競爭關係，因此產生警戒，故活動力下降，同時槍蝦的活動力也下降。
4. 1840~1938 4.6~7.3kHz +>10kHz (超明顯)
==日落：==
4. 0340-0343 船(後端有一個從低頻到高頻的馬達聲(可能可以推論出船的行進方向))
5. 
6. 0359.00~0400.40 (rescue？)boat <1kHz非常明顯 
![](https://i.imgur.com/yTDi6XS.png)
                                       ![](https://i.imgur.com/x0Wkhh0.png)
![](https://i.imgur.com/B6SjHR1.png)


4. 0400~0439 all fre 藍轉黃
==慢慢恢復==
5. 0439~0521 2.7~7.3 kHz +>10kHz (超明顯)
==慢慢恢復+日出==

### anomalies in frequency
1. <300Hz 兩種魚
3. 500~1000Hz 一種魚
4. 1~3.5kHz 摳摳槍蝦 偶發事件
5. 2.7~7.3 kHz、10.7~20k Hz all time
6. 已確定和蟹守螺無關
7. 

## Q&A

* Q2. 為何聲音在海水中不易被吸收?
* Q3. the meaning of sampling frequency?
* Q4. 

## 相關係數分析
1.dB和光度
2.dB和潮位
3.dB對溫度
## References
潮汐與槍蝦
Inyong Jeong and Dong-Guk Paeng(2022)。Circadian and Tidal Changes in Snapping Shrimp
(Alpheus brevicristatus) Sound Observed by a Moored
Hydrophone in the Coastal Sea of Western Jeju。Applied Sciences，6493，6。![](https://i.imgur.com/5AzZ5um.png)

==海洋生物時頻譜
https://ejournal.stpi.narl.org.tw/sd/download?source=10712-09.pdf&vlId=1714245f06b444338ef516f2b64eccd6&nd=1&ds==
雀鯛求偶時會發出叫聲
H. Yan. (translated from Chinese)(2021)。The Senses of Fish. (translated from Chinese) The Omics in the Ocean(translated from Chinese), 109, 105~107.
==雀鯛active time (P18)、魚類發聲原理
https://www.discoverboating.com/resources/best-times-for-saltwater-freshwater-fishing==

Yuqing, M., Yanan, L., & Shuyong, Z. (2016). Analysis of the physical chemistry principles of the strike process of snapping shrimp. Chemistry, 7, 16.
http://course.sdu.edu.cn/Download2/20210822222611424.pdf
Lin, T., Chou, T., Huang, C. (translated from Chinese) (2021). Soundscapes Underwater at Chaojing Park, Keelung and Guangshing Sea Area, Taoyuan. (translated from Chinese) (Version 2021-11-24T07:28:08.760764) 
[Data set]. https://pid.depositar.io/ark:37281/k5g258093
https://data.depositar.io/dataset/cea0c/resource/b96c319f-999c-4861-bd8b-bfaf1732a463

Lillis, A., & Mooney, T. A. (2018). Snapping shrimp sound production patterns on Caribbean coral reefs: relationships with celestial cycles and environmental variables. Coral Reefs, 37(2), 597-607.
https://www2.whoi.edu/site/amooney/wp-content/uploads/sites/31/2018/06/Lillis_Mooney_2018_CR.pdf

==鰕虎(或其他魚)發聲機制與特徵
(https://ejournal.stpi.narl.org.tw/sd/download?source=10805-04.pdf&vlId=744d20a3f16042e8abd0435006dac0cf&nd=1&ds=1)==

![](https://i.imgur.com/P5cHXTw.png)
![](https://i.imgur.com/DjrOSmp.png)

==https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4711987/

https://espace.curtin.edu.au/bitstream/handle/20.500.11937/47625/246321_246321.pdf?sequence=2
https://www.researchgate.net/publication/275583013_Nocturnal_diurnal_crepuscular_activity_assessments_of_Pisauridae_and_Lycosidae==




Class A:
A-槍蝦
B-槍蝦
C-槍蝦
D-槍蝦
雀鯛

Class B:
溫度
光度
潮位
人類潛水活動密度
人類船舶密度

共5*5=25種 


## 生物性問題
* 晨昏性生物的定義?
* 日夜行性的定義(日-夜/日+夜)


