Answers.Body: <p>There are some good answers in the thread already, but thought it might be nice to collate them into a more complete and structured response.</p>
  <p>Ultimately, there have been a range of solutions to this problem over the years for various scenarios and platforms. I've grouped my response by platform type just for the sake of readability.</p>
  <p><strong>Mobile platforms</strong> (but not towed or attached your ship)</p>
  <p>Sonobuoys can transmit sounds over radio in real-time and have a long history for whale research (see e.g. <a href="https://jcaa.caa-aca.ca/index.php/jcaa/article/view/1599" rel="nofollow noreferrer">McDonald et al 2003</a>). They are usually temporary devices with a lifespan measured in hours, and if used this way, then lots of them are required to be deployed in succession for sustained monitoring over longer time periods. However several studies over the years describe how they can be repurposed into a reusable form (e.g. <a href="http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=16836" rel="nofollow noreferrer">Horsley 1989</a>, <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1748-7692.1998.tb00719.x" rel="nofollow noreferrer">Van Parijs et al 1998</a>, <a href="https://repository.library.noaa.gov/view/noaa/20265" rel="nofollow noreferrer">Rankin et al 2019</a>). Alternatively, there have been some studies that have achieved the same effect as a reusable sonobuoy, but have started from a clean slate (e.g. <a href="http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=4623833" rel="nofollow noreferrer">Baumgartner et al 2008</a> comes to mind).</p>
  <p>More recently the idea has been extended to autonomous vehicles, with on-board near real-time processing and satellite communications. Usually to reduce the amount of data sent over the expensive satellite link only a summary or portion of the detections are sent back in near real-time (e.g. <a href="https://doi.org/10.1121/10.0004817" rel="nofollow noreferrer">Baumgartner et al 2021</a>, <a href="https://asa.scitation.org/doi/10.1121/10.0010124" rel="nofollow noreferrer">Johnson et al 2022</a>, <a href="http://asa.scitation.org/doi/10.1121/10.0001811" rel="nofollow noreferrer">Kowarski et al 2020</a>).</p>
  <p><strong>Fixed platforms</strong></p>
  <p>Fixed platforms include moorings and cabled arrays.</p>
  <p>Moorings are conceptually the same as the mobile platforms, but with an anchor (and all of the benefits and limitations that brings). They can have a terrestrial or satellite radio link, and can transmit 'raw' acoustic data or just detections. There are some commercially available products in this category from <a href="https://www.smruconsulting.com/cabgrd" rel="nofollow noreferrer">SMRU Ltd</a> and <a href="https://www.jasco.com/observerbuoy-06m" rel="nofollow noreferrer">Jasco</a> that have already been mentioned in this thread. There are also custom scientific solutions (possibly commercially available, but a bit unclear) like the <a href="https://www.whoi.edu/press-room/news-release/new-whale-detection-buoys-will-help-ships-take-the-right-way-through-marine-habitat/" rel="nofollow noreferrer">WHOI/Cornell BRP NARW moorings mentioned</a> in <a href="https://int-res.com/abstracts/meps/v395/p21-36" rel="nofollow noreferrer">Van Parijs et al (2009)</a> and <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/2041-210X.13244" rel="nofollow noreferrer">Baumgartner et al (2019)</a>.</p>
  <p>Cabled arrays/observatories are pretty rare due to high costs of running submarine cables and servicing sensors. The main example that comes to mind for me for bioacoustics is the <a href="https://www.ctbto.org/our-work/monitoring-technologies/hydroacoustic-monitoring" rel="nofollow noreferrer">CTBTO, who operates several cabled observatories around the world to monitor</a> for nuclear explosions. While I believe they can monitor in near-real time, I think most bioacousticians end up accessing their archived data rather than any real-time data stream. Additionally, the <a href="https://www.iqoe.org/systems" rel="nofollow noreferrer">International Quiet Ocean Experiment has a public website with a list of some other cabled observatories</a> that's worth checking out.</p>
  <p>Though cabled observatories can be quite expensive, there has been some work in recent years towards repurposing existing undersea fibre-optic cables for underwater acoustic monitoring. <a href="https://www.frontiersin.org/articles/10.3389/fmars.2022.901348/full" rel="nofollow noreferrer">Buoffaut et al (2022) provide an example</a>, of how this can be done in real-time.</p>
  <p>The above is not at all a fully comprehensive list, but should hopefully serve as a useful summary.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
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Answers.Body: <p>The answer depends on information that you did not present.</p>
  <p>A solution for shallow water applications is different to the one for deep water application. Also the distance from shore is important. Thirdly, does your budget allow for ocean-ready moored buoys that can provide power and fast data link? Do you have a single species of interest or any whale and dolphin should be reported?</p>
  <p>A possible system can be designed if the experimental contraints are well defined.</p>
  
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Answers.Text: Along these lines, there's an aging, but still highly relevant paper that might be of interest: Van Parijs, S., Clark, C. W., Sousa-Lima, R. S., Parks, S. E., Rankin, S., Risch, D., et al. (2009). Management and research applications of real-time and archival passive acoustic sensors over varying temporal and spatial scales. Marine Ecology Progress Series 395, 21–36. doi: 10.3354/meps08123(https://www.int-res.com/abstracts/meps/v395/p21-36)
Answers.UserDisplayName: Brian Miller
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Answers.Body: <p>Look at the CAB moorings by SMRU Consulting: <a href="https://www.smruconsulting.com/cabsnt" rel="nofollow noreferrer">https://www.smruconsulting.com/cabsnt</a></p>
  
Answers.ContentLicense: CC BY-SA 4.0
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Answers.Text: Yes, a nice picture, but with no explonatory text, specifications, etc. (at least I could not find it)
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Answers.Text: Check their other model, it has a product sheet and some more details on the site. I believe the system uses Pamguard in real time and can send detections via radio, cell phone network, or satellite link.  Another company with similar real-time moorings is JASCO with their ObserverBuoy, several versions, see https://www.jasco.com/observerbuoy-06m
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Body: <p>Methodology problem: If soundtrapping whales with an array of hydrophones that are set out for ~1 year underwater, is data collection purely physical? As in do you have to wait until the end of the soundtrapping period before collecting from the on-board storage? Or are there any hydrophones that can be set out and ping an alert to a computer remotely?</p>
  <p>Sum: Is there any way of using fixed hydrophones (not held from a boat) that detect the presence of whales in real-time? Can you suggest a hydrophone for this?</p>
  
Tags: <soundtrap><hydrophone>
Title: Looking for a suitable hydrophone where data can be monitored remotely (does it exist?)
ThreadText: # Looking for a suitable hydrophone where data can be monitored remotely (does it exist?)
  
  (Asked by: username_0 on 2024-03-11)
  
  Methodology problem: If soundtrapping whales with an array of hydrophones that are set out for ~1 year underwater, is data collection purely physical? As in do you have to wait until the end of the soundtrapping period before collecting from the on-board storage? Or are there any hydrophones that can be set out and ping an alert to a computer remotely?
  
  Sum: Is there any way of using fixed hydrophones (not held from a boat) that detect the presence of whales in real-time? Can you suggest a hydrophone for this?
  
  **Tags:** soundtrap, hydrophone
  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_1 on 2024-03-27. Score: 3
  
  There are some good answers in the thread already, but thought it might be nice to collate them into a more complete and structured response.
  
  Ultimately, there have been a range of solutions to this problem over the years for various scenarios and platforms. I've grouped my response by platform type just for the sake of readability.
  
  **Mobile platforms** (but not towed or attached your ship)
  
  Sonobuoys can transmit sounds over radio in real-time and have a long history for whale research (see e.g. [McDonald et al 2003](https://jcaa.caa-aca.ca/index.php/jcaa/article/view/1599)). They are usually temporary devices with a lifespan measured in hours, and if used this way, then lots of them are required to be deployed in succession for sustained monitoring over longer time periods. However several studies over the years describe how they can be repurposed into a reusable form (e.g. [Horsley 1989](http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=16836), [Van Parijs et al 1998](https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1748-7692.1998.tb00719.x), [Rankin et al 2019](https://repository.library.noaa.gov/view/noaa/20265)). Alternatively, there have been some studies that have achieved the same effect as a reusable sonobuoy, but have started from a clean slate (e.g. [Baumgartner et al 2008](http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=4623833) comes to mind).
  
  More recently the idea has been extended to autonomous vehicles, with on-board near real-time processing and satellite communications. Usually to reduce the amount of data sent over the expensive satellite link only a summary or portion of the detections are sent back in near real-time (e.g. [Baumgartner et al 2021](https://doi.org/10.1121/10.0004817), [Johnson et al 2022](https://asa.scitation.org/doi/10.1121/10.0010124), [Kowarski et al 2020](http://asa.scitation.org/doi/10.1121/10.0001811)).
  
  **Fixed platforms**
  
  Fixed platforms include moorings and cabled arrays.
  
  Moorings are conceptually the same as the mobile platforms, but with an anchor (and all of the benefits and limitations that brings). They can have a terrestrial or satellite radio link, and can transmit 'raw' acoustic data or just detections. There are some commercially available products in this category from [SMRU Ltd](https://www.smruconsulting.com/cabgrd) and [Jasco](https://www.jasco.com/observerbuoy-06m) that have already been mentioned in this thread. There are also custom scientific solutions (possibly commercially available, but a bit unclear) like the [WHOI/Cornell BRP NARW moorings mentioned](https://www.whoi.edu/press-room/news-release/new-whale-detection-buoys-will-help-ships-take-the-right-way-through-marine-habitat/) in [Van Parijs et al (2009)](https://int-res.com/abstracts/meps/v395/p21-36) and [Baumgartner et al (2019)](https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/2041-210X.13244).
  
  Cabled arrays/observatories are pretty rare due to high costs of running submarine cables and servicing sensors. The main example that comes to mind for me for bioacoustics is the [CTBTO, who operates several cabled observatories around the world to monitor](https://www.ctbto.org/our-work/monitoring-technologies/hydroacoustic-monitoring) for nuclear explosions. While I believe they can monitor in near-real time, I think most bioacousticians end up accessing their archived data rather than any real-time data stream. Additionally, the [International Quiet Ocean Experiment has a public website with a list of some other cabled observatories](https://www.iqoe.org/systems) that's worth checking out.
  
  Though cabled observatories can be quite expensive, there has been some work in recent years towards repurposing existing undersea fibre-optic cables for underwater acoustic monitoring. [Buoffaut et al (2022) provide an example](https://www.frontiersin.org/articles/10.3389/fmars.2022.901348/full), of how this can be done in real-time.
  
  The above is not at all a fully comprehensive list, but should hopefully serve as a useful summary.
  
  
  ---
  
  ### Answer by username_2 on 2024-03-11. Score: 1
  
  The answer depends on information that you did not present.
  
  A solution for shallow water applications is different to the one for deep water application. Also the distance from shore is important. Thirdly, does your budget allow for ocean-ready moored buoys that can provide power and fast data link? Do you have a single species of interest or any whale and dolphin should be reported?
  
  A possible system can be designed if the experimental contraints are well defined.
  
  > **Comments:**
  > **username_1**: Along these lines, there's an aging, but still highly relevant paper that might be of interest: Van Parijs, S., Clark, C. W., Sousa-Lima, R. S., Parks, S. E., Rankin, S., Risch, D., et al. (2009). Management and research applications of real-time and archival passive acoustic sensors over varying temporal and spatial scales. Marine Ecology Progress Series 395, 21–36. doi: 10.3354/meps08123(https://www.int-res.com/abstracts/meps/v395/p21-36)  
  
  ---
  
  ### Answer by username_3 on 2024-03-22. Score: 1
  
  Look at the CAB moorings by SMRU Consulting: <https://www.smruconsulting.com/cabsnt>
  
  > **Comments:**
  > **username_2**: Yes, a nice picture, but with no explonatory text, specifications, etc. (at least I could not find it)  
  > **username_3**: Check their other model, it has a product sheet and some more details on the site. I believe the system uses Pamguard in real time and can send detections via radio, cell phone network, or satellite link.  Another company with similar real-time moorings is JASCO with their ObserverBuoy, several versions, see https://www.jasco.com/observerbuoy-06m  
  
  ---
  
  