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EARTH SCIENCE > OCEANS > OCEAN ACOUSTICS

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  • Scanned copy of an acoustics log from Casey Station. Data were collected during 1997. There is no accompanying information to go with the log.

  • This dataset contains acoustic recordings from Directional Frequency Analysis and Recording (DIFAR) sonobuoys that were deployed from 30 January – 23 March 2021 during the TEMPO voyage. 251 sonobuoys were deployed yielding 460 hours of acoustic recordings. Three models of sonobuoys were used during the voyage: AN/SSQ-53F sonobuoy from SonobuoyTechSystems, USA (made in 2011; identifiable by tall black housing); Q53F sonobuoys from Ultra Electronics Australia (made in 2011 for Australian Defence; identifiable by tall silver housing); SDSQ955 (HIDAR) sonobuoys from Ultra Electronics UK (re-lifed in 2018; identifiable from small silver housing); During TEMPO, recordings were made by deploying above sonobuoys in DIFAR (standard) mode while the ship was underway (Gedamke and Robinson 2010, Miller et al. 2015). During transit, listening stations were conducted every 30 nmi in water depths greater than 200 m when Beaufort sea state was less than 7. Sonobuoys were occasionally deployed with spacing less than 30 nmi in an attempt to more precisely determine spatial extent and vocal characteristics of calls that were believed to be coming from animals relatively close to the ship’s track. During marine science stations, sonobuoys were deployed approximately 2-4 nmi prior to stopping in order to attempt to monitor them for the full six-eight hour duration of their operational life or the duration of the station. The sampling regime was chosen for compatibility with previous surveys, and to balance spatial resolution with the finite number of sonobuoys available for this study. Instrumentation, software, and data collection At each listening station, a sonobuoy was deployed with the hydrophone set to a depth near 140 m. Sonobuoys transmitted underwater acoustic signals from the hydrophone and directional sensors back to the ship via a VHF radio transmitter. Radio signals from the sonobuoy were received using an omnidirectional VHF antenna (PCTel Inc. MFB1443; 3 dB gain tuned to 144 MHz centre frequency) and a Yagi antenna (Broadband Propagation Pty Ltd, Sydney Australia) mounted on the aft handrail of the flying bridge. The antennas were each connected to a WiNRADiO G39WSBe sonobuoy receiver via low-loss LMR400 coaxial cable via a cavity filter with 1 MHz passband centered on 144 MHz. The radio reception range on the Yagi antenna was similar to previous Antarctic voyages, and was adequate for monitoring and localisation typically out to a range of 10-12 nmi, provided that the direction to the sonobuoy was close (i.e. within around 30o) to the main axis of the antenna. The radio reception on the omnidirectional antenna typically provided 5-10 nmi of omnidirectional reception from sonobuoys. At transit speed (8-11 knots), the Yagi antenna provided about 75 minutes of acoustic recording time per sonobuoy. Using both antennas together were able obtain radio reception for up to six hours (i.e. the maximum life of a 955 sonobuoy) when sonobuoys were deployed within 5 nmi of a marine science station. Received signals were digitised via the instrument inputs of a Fireface UFX sound board (RME Fireface; RME Inc.). Digitised signals were recorded on a personal computer as 48 kHz 24-bit WAV audio files using the software program PAMGuard (Gillespie et al. 2008). Data from both the Yagi and Omnidirectional antenna were recorded simultaneously as WAV audio channels 0 (left) and 1 (right). Each recorded WAV file therefore contains a substantial amount of duplication since both antennas and receivers were usually receiving the same signals from the same sonobuoy. Directional calibration The magnetic compass in each sonobuoy was not calibrated/validated upon deployment because the ship did not generate enough noise. Intensity calibration Intensity calibration and values followed those described in Rankin et al (2019). Sonobuoy deployment metadata The PAMGuard DIFAR Module (Miller et al. 2016) was used to record the sonobuoy deployment metadata such as location, sonobuoy deployment number, and audio channel in the HydrophoneStreamers table of the PAMGuard database (IN2021_V01_Difar-2021-01-22.sqlite3). A written sonobuoy deployment log (SonobuoyLog.pdf) was also kept during the voyage, and this includes additional notes and additional information not included in the PAMGuard Database such as sonobuoy type, and sonobuoy end-time. Real-time monitoring and analysis: Aural and visual monitoring of audio and spectrograms from each sonobuoy was conducted using PAMGuard for at least 5 minutes after deployment only to validate that the sonobuoy was working correctly. Additional information about sonobuoys is contained in the file: Sonobuoy data collection during the TEMPO voyage - 2021-01-15.pdf References Greene, C.R.J. et al., 2004. Directional frequency and recording ( DIFAR ) sensors in seafloor recorders to locate calling bowhead whales during their fall migration. Journal of the Acoustical Society of America, 116(2), pp.799–813. Miller, B.S. et al., 2016. Software for real-time localization of baleen whale calls using directional sonobuoys: A case study on Antarctic blue whales. The Journal of the Acoustical Society of America, 139(3), p.EL83-EL89. Available at: http://scitation.aip.org/content/asa/journal/jasa/139/3/10.1121/1.4943627. Miller, B.S. et al., 2015. Validating the reliability of passive acoustic localisation: a novel method for encountering rare and remote Antarctic blue whales. Endangered Species Research, 26(3), pp.257–269. Available at: http://www.int-res.com/abstracts/esr/v26/n3/p257-269/. Rankin, S., Miller, B., Crance, J., Sakai, T., and Keating, J. L. (2019). “Sonobuoy Acoustic Data Collection during Cetacean Surveys,” NOAA Tech. Memo. NMFS, SWFSC614, 1–36.

  • Readme - Bathymetry Files Data for BROKE-WEST 2006 1) Zipped folder contains .csv files created from each acoustics ev file for Transects 1 to 11. 2) These files contain subsections of each transect of variable length (usually between 50 and 100 km). 3) No data exists for files; Transect01_01 and 01_02 as the sea floor was greater than 5000m deep in these areas and was below the range set for the sounder. 4) Each file contains 11 columns of data; Ping_date, Ping_time, Ping_milliseconds, Latitude, Longitude, Position_status, Depth, Line_Status, Ping_status, Altitude, GPS_UTC time. 5) For practical purposes, the columns of interest will be Ping_date, Ping_time, Latitude, Longitude and Depth. Other columns are ancillary acoustics information and can be ignored. Line status should be 1 (meaning good) as sea floor was only picked when it could be easily defined. If the sea floor could not be visually defined or was deemed to uncertain, it was not picked in the echogram. Hence sea floor may not be totally contiguous. 6) Depth of the sea floor was only defined for those areas deemed to be 'on transect', i.e. straight transects for acoustics survey purposes. Deviations from the transect, i.e. to pick up moorings, conduct target or routine trawls or visit nice looking bergs were deemed 'off transect' and were excluded from the analysis. 7) Sea floor depth was primarly defined for the purposes of the acoustics analysis, i.e. exclusion from the echograms. Hence the values in the files are for the 'sea floor exclusion line' that is set above the true sea floor in order to exclude noise from the analysis. This means the sea floor depths in these files are likely to be an underestimate of the true depth. The uncertainty is likely to be of the order of 2 to 10m. 8) Another source of error is that depth was calculated with values of absorption coefficient and sound speed set to default values derived from pre-cruise hydrographic data. One value for each parameter was applied to the whole data set. These values were; 0.028 dB/m (120 KhZ), 0.010 dB/m (38kHz), 0.041 dB/m (200 kHz), 0.0017 dB/m (12kHz - bathy sounder) for absorption coefficient and 1456 m/s for sound speed. 9) These values will be recalculated from the oceanographic data derived during the voyage and applied to the data set during post-processing (forthcoming analyses for May-June 2006). Revision of these parameters may cause a slight shift in the calculated depths, although this is likely to be small. 10) Reprocessing of the data may also result in more accurate bottom detection. This data should be available post June 2006 and will be sent to interested parties as soon as it is completed. 11) Dataset was created by Esmee van Wijk.

  • This annotated library contains both a data set and a data product. The data set contains a sub-sample of underwater recordings made around Antarctica from 2005-2017. These recordings were curated and sub-sampled from a variety of national and academic recording campaigns. Recordings were made using a variety of different instruments, and sub-samples span 11 different combinations of site and year. Spatial coverage of the recordings includes sites in the Western Antarctic Peninsula, Atlantic, Indian, and Pacific sectors. Temporal coverage of recordings covers a representative sample throughout each recording year for the years of 2005, 2013, 2014, 2015, and 2017. The focus is on low-frequency sounds of blue and fin whales, so curated recordings have been downsampled to sample rates of either 250, 500, 1000 or 2000 Hz. Recordings are all in 16-bit wav format. The file name of each wav file contains a timestamp with the date and time of the start of that file. Recordings are contained in the /wav/ subfolder for each site-year (e.g. Casey2014/wav). The data product is in the form of annotations that describe the times within each WAV file that contain detections of blue and fin whale sounds. Each annotations are stored as a row in a tab-separated text file (with descriptive column headers), and each text file describes a particular type of sound. These annotation text files are formatted as Selection Tables that can be directly imported into the software program Raven Pro 1.5 (Cornell Bioacoustics Laboratory). Full description of the details of the creation and use of this dataset are described in the draft manuscript contained in the documentation folder.

  • Bathymetry data was collected using a Simrad EK60 echosounder. The sample data have been corrected for the relative locations of GPS antenna, transducers and waterline. A sound-speed value of 1500 m/s was applied when calculating depth. The seafloor depth itself was defined firstly as the depth of the sounder-detected bottom minus 10m (contact Simrad for more information about their bottom-detection algorithm), and then modified manually where necessary to ensure that the line followed the seafloor as perceived by eye from the echogram. This is therefore a subjective process, and the true seafloor depth may vary from the perceived depth by several hundred metres in the worst cases. The greatest uncertainties are typically at greater depths, e.g. greater than 1000 m. This seafloor depth line therefore refers to the approximate depth (not range from transducer) of the seafloor less 10 m, i.e. 10 m should be added to the 'depth' values in the *.CSV file to give the 'true' seafloor depth. Depths greater than 5000 m are not available due to the 12 kHz data not being logged any deeper than this. These data are preliminary and subject to change. Bathymetry data was exported during the voyage by Belinda Ronai. Post voyage enquiries however should be directed to Toby Jarvis.

  • This dataset contains estimates of krill swarm characteristics from statistical models based on underway acoustic observations along with underway and remote-sensed environmental data. Estimates of internal swarm density and depth across the study region (60-80 degrees E) are included for the time of the survey (Feb 2006). Estimates of February internal swarm density across the broader East Antarctic region (30-120 degrees E) are also included for the period 2001-2010.

  • This dataset contains the data from Voyage 7.2 1989-90 of the Aurora Australis. The observations were taken from around Heard Island between May and June 1990. The objective of the zooplankton program was to determine the composition, distribution and abundance of zooplankton with the Heard Island-Kerguelen area, thus providing information of food availability to planktivorous fish. Surveys of krill and other zooplankton were made to obtain species identity and abundance data, length and age. Euphausia valentini and Themisto gaudichaudi were found to be the dominant species in the region. Other major species included the euphausiid Thysanoessa, the copepod Rhincalanus gigas and chaetognaths of the genus Sagitta. This dataset is a subset of the full cruise.

  • A routine was developed in R ('bathy_plots.R') to plot bathymetry data over time during individual CEAMARC events. This is so we can analyse benthic data in relation to habitat, ie. did we trawl over a slope or was the sea floor relatively flat. Note that the depth range in the plots is autoscaled to the data, so a small range in depths appears as a scatetring of points. As long as you look at the depth scale though interpretation will be ok. The R files need a file of bathymetry data in '200708V3_one_minute.csv' which is a file containing a data export from the underway PostgreSQL ship database and 'events.csv' which is a stripped down version of the events export from the ship board events database export. If you wish to run the code again you may need to change the pathnames in the R script to relevant locations. If you have opened the csv files in excel at any stage and the R script gets an error you may need to format the date/time columns as yyyy-mm-dd hh;mm:ss, save and close the file as csv without opening it again and then run the R script. However, all output files are here for every CEAMARC event. Filenames contain a reference to CEAMARC event id. Files are in eps format and can be viewed using Ghostview which is available as a free download on the internet.

  • This dataset contains data files, processing templates and documentation relating to the BROKE-West multifrequency echosounder (acoustic) survey carried out from the RSV Aurora Australis in the austral summer of 2005/06 (ASAC project 2655). The primary aim of the acoustic survey was to describe the distribution and abundance of Antarctic krill (Euphausia superba) in CCAMLR Division 58.4.2. However, these data are also relevant for studies of other sound-scattering targets detected by the echosounder system, for example other pelagic taxa or the seafloor. The dataset is a collection of *.csv data files, *.ev processing files and *.pdf documentation files, organised into 4 categories: 1. Acoustic survey: data files relating to the transects undertaken for the acoustic survey 2. Acoustic data processing: metadata files, processing templates and documentation relating to the collection and processing of the acoustic data 3. Acoustic results: results arising from the processing of the raw data. The raw data are described in a separate metadata record - "AAD Hydroacoustics hard disks - data collected from Southern Ocean cruises..." 4. Ancillary data: additional non-acoustic data used during the processing of the acoustic data The file "data_fields.pdf" lists and describes the fields in each of the *.csv data files. The file "processing_methods.pdf" provides a synopsis of the methods by which the raw acoustic data were collected and processed. The BROKE-West survey was conducted on voyage 3 of the Aurora Australis during the 2005-3006 season. It was intended to be a comprehensive biological and oceanographic survey of the region between 30 degrees and 80 degrees east.

  • This dataset contains acoustic recordings from Directional Frequency Analysis and Recording (DIFAR) sonobuoys that were deployed from 19 January – 5 March 2019 during the ENRICH (Euphausiids and Nutrient Recycling in Cetacean Hotspots) voyage. 295 sonobuoys were deployed yielding 828 hours of acoustic recordings. Passive acoustic research during ENRICH took the form of both broad-scale structured surveys and fine-scale adaptive surveys depending on the operational mode of the ship. Regardless of the mode of operation, listening stations were conducted by deploying SSQ955 sonobuoys (commonly called HIDAR sonobuoys) in Directional and Frequency Analysis and Recording (DIFAR) mode to monitor for and measure bearings to vocalising whales while the ship was underway (Miller et al. 2015). During transit, listening stations were conducted every 30 nmi in water depths greater than 200 m when Beaufort sea state was less than 7. During marine science stations, sonobuoys were deployed approximately 2-4 nmi prior to stopping in order to attempt to monitor them for the full six-eight hour duration of their operational life or the duration of the station. The sampling regime was chosen for compatibility with previous surveys, and to balance spatial resolution with the finite number of sonobuoys available for this study. During portions of the voyage dedicated to passive acoustic tracking, multiple sonobuoys were deployed concurrently to precisely locate Antarctic blue whales (Miller et al. 2015, 2016). Bearings from single sonobuoys, pairs, or triplets were also followed in order to track, locate, and sight blue whales to obtain visual observations of group size, behavior, and photographic identifications. Tracking was conducted during 10 days spread throughout the voyage: 30 Jan, and 2, 5, 9, 13, 17, 19, 22-24 Feb 2019 for a total of 124.1 hours. When conducting activities with whales, sonobuoys were deployed adaptively, often in pairs or triplets with 6-9 nmi spacing. When possible during acoustic tracking, the acousticians also continued to monitor other groups of whales that were judged to be nearby (e.g. within a 20-30 nmi radius of the array), as well as more distant animals. Triplets of sonobuoys were also occasionally deployed during small-scale active acoustic surveys even if there was no opportunity to approach whales. Instrumentation, software, and data collection At each listening station, a sonobuoy was deployed with the hydrophone set to a depth near 140 m. Sonobuoys transmitted underwater acoustic signals from the hydrophone and directional sensors back to the ship via a VHF radio transmitter. Radio signals from the sonobuoy were received using an omnidirectional VHF antenna (PCTel Inc. MFB1443; 3 dB gain tuned to 144 MHz centre frequency) and a Yagi antenna (Broadband Propagation Pty Ltd, Sydney Australia) mounted on the aft handrail of the flying bridge. The antennas were each connected to a WiNRADiO G39WSBe sonobuoy receiver via low-loss LMR400 coaxial cable. The radio reception range on the Yagi antenna was similar to previous Antarctic voyages, and was adequate for monitoring and localisation typically out to a range of 10-12 nmi, provided that the direction to the sonobuoy was close (i.e. within around 30o) to the main axis of the antenna. The radio reception on the omnidirectional antenna typically provided 5-10 nmi of omnidirectional reception from sonobuoys. At transit speed (8-11 knots), the Yagi antenna provided about 75 minutes of acoustic recording time per sonobuoy. Using both antennas together were able obtain radio reception for up to six hours (i.e. the maximum life of a 955 sonobuoy) when sonobuoys were deployed within 5 nmi of a marine science station. Received signals were digitised via the instrument inputs of a Fireface UFX sound board (RME Fireface; RME Inc.). Digitised signals were recorded on a personal computer as 48 kHz 24-bit WAV audio files using the software program PAMGuard (Gillespie et al. 2008). Data from both the Yagi and Omnidirectional antennas were recorded simultaneously as WAV audio channels 0 (left) and 1 (right) and 2. Each recorded WAV file therefore contains a substantial amount of duplication since both antennas and receivers were usually receiving the same signals from the same sonobuoy. Directional calibration The magnetic compass in each sonobuoy was not calibrated/validated upon deployment because the ship did not generate enough noise. Intensity calibration Intensity calibration and values followed those described in Rankin et al (2019). Sonobuoy deployment metadata The PAMGuard DIFAR Module (Miller et al. 2016) was used to record the sonobuoy deployment metadata such as location, sonobuoy deployment number, and audio channel in the HydrophoneStreamers table of the PAMGuard database (In2019_V01.sqlite3). A written sonobuoy deployment log (SonobuoyLog.pdf) was also kept during the voyage, and this includes additional notes and additional information not included in the PAMGuard Database such as sonobuoy type, and sonobuoy end-time. Real-time monitoring and analysis: Aural and visual monitoring of audio and spectrograms from each sonobuoy was conducted using PAMGuard for at least 5 minutes after deployment only to validate that the sonobuoy was working correctly. Additional information about sonobuoys is contained in the file: Sonobuoy data collection during the TEMPO voyage - 2021-01-15.pdf References Greene, C.R.J. et al., 2004. Directional frequency and recording ( DIFAR ) sensors in seafloor recorders to locate calling bowhead whales during their fall migration. Journal of the Acoustical Society of America, 116(2), pp.799–813. Miller, B.S. et al., 2016. Software for real-time localization of baleen whale calls using directional sonobuoys: A case study on Antarctic blue whales. The Journal of the Acoustical Society of America, 139(3), p.EL83-EL89. Available at: http://scitation.aip.org/content/asa/journal/jasa/139/3/10.1121/1.4943627. Miller, B.S. et al., 2015. Validating the reliability of passive acoustic localisation: a novel method for encountering rare and remote Antarctic blue whales. Endangered Species Research, 26(3), pp.257–269. Available at: http://www.int-res.com/abstracts/esr/v26/n3/p257-269/. Rankin, S., Miller, B., Crance, J., Sakai, T., and Keating, J. L. (2019). “Sonobuoy Acoustic Data Collection during Cetacean Surveys,” NOAA Tech. Memo. NMFS, SWFSC614, 1–36.