DIFAR
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During the 2013 Antarctic Blue Whale Voyage Acousticians noted all whale calls and other acoustic events that were detected during real-time monitoring in a Sonobuoy Event Log. The acoustic tracking software, difarBSM, stored processed bearings from acoustic events and cross bearings in tab delimited text files. Each event was assigned a classification by the acoustician, and events for each classification were stored in separate text files. The first row in each file contains the column headers, and the content of each column is as follows: buoyID: Buoy ID number is the number of the sonobuoy on which this event was detected. This can be used as a foreign key to link to the sonobuoy deployment log. timeStamp_matlabDatenum: Date and time (UTC) at the start of the event represented as a Matlab datenum (i.e. number of days since Jan 0 0000). Latitude: Latitude of the sonobuoy deployment in decimal degrees. Southern hemisphere latitudes should be negative. Longitude: Longitude of sonobuoy deployment in decimal degrees. Western hemisphere longitudes should be negative. Altitude: Depth of the sonobuoy deployment in metres. For DIFAR sonobuoys either 30, 120 or 300. magneticVariation_degrees: The estimated magnetic variation of the sonobuoy in degrees at the time of the event. Positive declination is East, negative is West. At the start of a recording this will be entered from a chart. As the recording progresses, this should be updated by measuring the bearing to the vessel. bearing_degreesMagnetic: Magnetic bearing in degrees from the sonobuoy to the acoustic event. Magnetic bearings were selected by the acoustician by choosing a single point on the bearing-frequency surface (AKA DIFARGram) produced by the analysis software difarBSM. frequency_Hz: The frequency in Hz of the magnetic bearing that the acoustician selected from the bearing-frequency surface (DIFARGram). logDifarPower: The base 10 logarithm of the height of the point on the DIFARGram receiveLevel_dB: This column contains an estimate of the The RMS receive level (dB SPL re 1 micro Pa) of the event. Received levels were estimated by applying a correction for the shaped sonobuoy frequency response, the receiver’s frequency response, and were calculated over only the frequency band specified in each classification (see below). soundType: soundType is the classification assigned to the event by the acoustician. Analysis parameters for each classification are included in the csv file classificationParameters.txt. The columns of this file are as follows: outFile: The name of the tab-separated text file that contains events for this classification. analysisType: A super-class describing the broad category of analysis parameters soundType: The name of the classification sampleRate: When events are processed, they are downsampled to this sample rate (in Hz) in order to make directional processing more efficient and precise FFTLength: The duration (in seconds) used for determining the size of the FFT during difar beamforming (i.e. creation of the DIFARGram). numFreqs: Not used during this voyage targetFreq: The midpoint of the frequency axis (in Hz) displayed in the DIFARGram Bandwidth: This describes the half-bandwidth (Hz) of the frequency axis of the DIFARGram. The frequency axis of the DIFARGram starts at targetFreq-bandwidth and ends at targetFreq + bandwidth frequencyBands_1: The lower frequency (Hz) used for determining RMS received level. frequencyBands_2: The upper frequency (Hz) used for determining RMS received level. preDetect: Duration of audio (in seconds) that will be loaded before the start of the event. The processed audio includes the time-bounds of the event marked by the acoustician as well as preDetect seconds before the start of the event. postDetect: Duration of audio (in seconds) that will be loaded after the end of the event. The processed audio includes the time-bounds of the event marked by the acoustician + postDetect seconds.
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This dataset contains acoustic recordings from Directional Frequency Analysis and Recording (DIFAR) sonobuoys that were deployed throughout the 2012 Blue Whale Voyages conducted off Portland, Victoria, Australia from January – March (in the Bonney Upwelling). During the 20 days at sea 131 AN/SSQ-53D sonobuoys were deployed yielding more than 500 hours of acoustic recordings. In January a total team of three dedicated acousticians monitored round-the-clock for blue whales and in all weather conditions. In March the team size was increased so that five acousticians monitored and tracked blue whales round-the-clock. The recording chain for all sonobuoy deployments through 25 March 2012 included a 3-dB communications antenna with a central frequency at 161 MHz and masthead amplifier connected to a passive four way splitter. The highest point of the antenna was approximately 14 m above sea level. The antenna, amplifier, and splitter were connected with low loss cable, and each output of the four way splitter connected to the DIFAR input of a WiNRaDiO 2902i sonobuoy VHF receiver. On 25 March the masthead amplifier failed and was removed from the recording chain. This failure prompted the use of recently acquired WiNRaDiO G39WSBe sonobuoy receivers. The A/D converter used throughout both voyages was a RME Fireface UFX. The voltage outputs of all of the sonobuoy receivers were calibrated as a function of modulation frequency before the voyage, and DIFAR outputs from each of the 2902i and G39WSBe were connected to an instrument input of the UFX. The instrument inputs of the UFX (analog inputs 9-12) have a peak-peak voltage range of 80 V with digitally controlled gain that can be set between 10-65 dB, and this setting was noted in the Sonobuoy Deployment Log (see below) in order to measure received sound-pressure levels accurately. The digitised signals from the UFX were saved as 16-bit WAV files with 48 kHz sample rate using passive acoustic monitoring software Pamguard. Directional calibration The magnetic compass in each sonobuoy was calibrated/validated upon deployment as described by Miller et al. (2015, 2016). Calibration procedure involved measuring the mean bearing error and standard deviation of errors between the GPS-derived bearing from the sonobuoy to the ship and the magnetic bearing to the ship noise detected by the sonobuoy. 15-30 bearings were used for each calibration as the ship steamed directly away from the deployment location. Intensity calibration Obtaining calibrated intensity measurements from sonobuoys not only requires knowledge of the sensitivity of the hydrophone, but also the calibration parameters of the radio transmitter and radio receiver. Throughout the voyage, a hydrophone sensitivity of -122 dB re 1 V/µPa was applied to recordings via the Hydrophone Array Manager in PAMGuard. This value is defined in the DIFAR specification as the reference intensity at 100 Hz that will generate a frequency deviation of 25 kHz (Maranda 2001), thus the specification combines the hydrophone sensitivity and transmitter calibration. In line with manufacturers specifications, the WiNRADiO G39 WSB and 2902i both had a measured voltage response of approximately 1 V-peak–peak (approximately -3 dB) at 25 kHz frequency deviation (Miller et al. 2014), and this can be subtracted from the hydrophone sensitivity to yield an total combined factor of 125 dB re 1 V/µPa. These calibration settings, along with the shaped filter response provided by Greene et al. (2004) make it possible to obtain calibrated pressure amplitude from the recorded WAV audio files. Sonobuoy deployment metadata (Sonobuoy deployment log) This spreadsheet contains metadata on the deployment of sonobuoys deployed during the 2013 Antarctic Blue Whale Voyage. The first row contains column headers, while each subsequent row contains deployment information for a single sonobuoy. Information contained in each column are: buoyID: Buoy ID number is the sequential number of the buoy starting at 1 for the first buoy of the trip. startDate: Date (UTC) at the start of the sonobuoy deployment (YYYY-MM-DD) startTime: Time (UTC) at the start of the sonobuoy deployment (HH:MM:SS) 2 digit hour with 24 hour clock and leading zero. stopDate: Date (UTC) at the end of the sonobuoy deployment (YYYY-MM-DD). While the recording is in progress this should be 1,2 4 or 8 hours after the startTime based on sonobuoy setting. stopTime: Time (UTC) at the end of the sonobuoy deployment (HH:MM:SS). While the recording is in progress this should be 1,2 4 or 8 hours after the startTime based on the sonobuoy setting. lat: Latitude of deployment in decimal degrees. Southern hemisphere latitudes should be negative. long: Longitude of deployment in decimal degrees. Western hemisphere longitudes should be negative. alt: Depth of the sonobuoy deployment in metres. For DIFAR sonobuoys either 30, 120 or 300. recordingChannel: This is the channel number within the recorded wav-file that contains audio from this buoy as would be reported by Matlab. Channel numbers start at 1 (1-indexed) so usually this will be 1, 2 or 3. magVariation: The magnetic variation in degrees. Positive declination is East, negative is West. At the start of a recording this will be entered from a chart. As the recording progresses, this should be updated by measuring the bearing to the vessel. sonobuoyType: The an/ssq designation for the sonobuoy. Usually 53B, 53D, 53F, HIDAR, 57A/B, or 36Q. receiver: The type and serial number of the calibrated radio receiver (WinRadio) used to receive the VHF signal. (wr15725, wr17274, wr15274, or wr15273) preamp: The (unitless) gain in dB of any preamplifier (including the instrument preamp from the Fireface UFX). Usually 10 or 20 dB. adc: The analog-to-digital converter (adc) used to digitize the audio. This is the sound card name and gain. All data were recorded on an RME Fireface UFX, so Ufx10 would be the RME Fireface UFX with a gain of 10 dB. vhfFreq: The VHF channel number used to receive the sonobuoys. Sonobuoys have 99 pre-set VHF channels between Real-time monitoring and analysis (Acoustic event log) During the 2012 Blue Whale Voyages Acousticians noted all whale calls and other acoustic events that were detected during real-time monitoring in a written Sonobuoy Event Log. Additionally, the acoustic tracking software, difarBSM, stored processed bearings from acoustic events and cross bearings in tab delimited text files. Each event was assigned a classification by the acoustician, and events for each classification were stored in separate text files. The first row in each file contains the column headers, and the content of each column is as follows: buoyID: Buoy ID number is the number of the sonobuoy on which this event was detected. This can be used as a foreign key to link to the sonobuoy deployment log. timeStamp_matlabDatenum: Date and time (UTC) at the start of the event represented as a Matlab datenum (i.e. number of days since Jan 0 0000). Latitude: Latitude of the sonobuoy deployment in decimal degrees. Southern hemisphere latitudes should be negative. Longitude: Longitude of sonobuoy deployment in decimal degrees. Western hemisphere longitudes should be negative. Altitude: Depth of the sonobuoy deployment in metres. For DIFAR sonobuoys either 30, 120 or 300. magneticVariation_degrees: The estimated magnetic variation of the sonobuoy in degrees at the time of the event. Positive declination is East, negative is West. At the start of a recording this will be entered from a chart. As the recording progresses, this should be updated by measuring the bearing to the vessel. bearing_degreesMagnetic: Magnetic bearing in degrees from the sonobuoy to the acoustic event. Magnetic bearings were selected by the acoustician by choosing a single point on the bearing-frequency surface (AKA DIFARGram) produced by the analysis software difarBSM. frequency_Hz: The frequency in Hz of the magnetic bearing that the acoustician selected from the bearing-frequency surface (DIFARGram). logDifarPower: The base 10 logarithm of the height of the point on the DIFARGram receiveLevel_dB: This column contains an estimate of the The RMS receive level (dB SPL re 1 micro Pa) of the event. Received levels were estimated by applying a correction for the shaped sonobuoy frequency response, the receiver’s frequency response, and were calculated over only the frequency band specified in each classification (see below). soundType: soundType is the classification assigned to the event by the acoustician. Aural and visual monitoring of audio and spectrograms from each sonobuoy was conducted for each sonobuoy deployment. Detections from marine mammals, and other sources and were detected and classified manually, and their time and frequency bounds were marked on the PAMGuard spectrogram. Parameters for monitoring and recording, were stored within the PAMGuard database and as stand-alone Pamguard Settings Files (PSF). During the voyage there were detections of pygmy blue whale song, and blue whale 'D-call' vocalisations. During the dedicated blue whale voyages the course of the ship was diverted to follow bearings to vocalising blue whales. Whale tracking log (Written Whale Acoustic Tracking Log - Tangaroa 2015.pdf) During the 2012 Blue Whale Voyages, noted all whale calls and other acoustic events that were detected during real-time monitoring in a Sonobuoy Event Log. A written summary of the event log was recorded during data collection at approximately 15 minute intervals, and this summary comprises the Whale Tracking Log. - Tracking Log. - Entries in the written Sonobuoy Tracking Log (on the bench in the acoustics workstation) also include total number of different whales heard in that 15 minute interval. - If multiple whales/groups were detected, then the acoustician on-duty, in consultation with the lead acoustician and/or voyage management designateded one of the whales the 'target' whale, and attempted to encounter this target first. - When targeting a whale/group, the acoustician on-duty continued to track all other whales/groups in the area as these tracked whales/groups may become the next target after obtaining concluding with the current target. Date: (UTC) written only at top of datasheet Time: (UTC) on the hour, 15 past, half past, and 15 to. Track: Unique identifier for each whale/group tracked in the past 15 minutes. Each track will have: Position: Either an average bearing from a sonobuoy (eg 220 degrees from SB18) or a Lat/Lon from the most recent triangulation Notes: What is the vessel action with respect to this tracked whale/group? (eg. Is this the current or previous 'target'? Are we presently photographing this whale? Did we finish photographing the whale?) Has the whale gone silent? Has this track crossed paths with another?
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During the 2013 Antarctic Blue Whale Voyage Acousticians noted all whale calls and other acoustic events that were detected during real-time monitoring in a Sonobuoy Event Log. A written summary of the event log was recorded during data collection at approximately 15 minute intervals, and this summary comprises the Whale Tracking Log. - The acoustician on-duty recorded the average bearings or locations of each calling whale/group every 15 minutes in the written Whale Tracking Log. - Entries in the written Sonobuoy Tracking Log (on the bench in the acoustics workstation) also include total number of different whales heard in that 15 minute interval. - If multiple whales/groups were detected, then the acoustician on-duty, in consultation with the lead acoustician and/or voyage management designateded one of the whales the 'target' whale, and attempted to encounter this target first. - When targeting a whale/group, the acoustician on-duty continued to track all other whales/groups in the area as these tracked whales/groups may become the next target after obtaining concluding with the current target. Date: (UTC) written only at top of datasheet Time: (UTC) on the hour, 15 past, half past, and 15 to. Track: Unique identifier for each whale/group tracked in the past 15 minutes. Each track will have: Location: Either an average bearing from a sonobuoy (eg 220 degrees from SB18) or a Lat/Lon from the most recent triangulation Notes: What is the vessel action with respect to this tracked whale/group? (eg. Is this the current or previous 'target'? Are we presently photographing this whale? Did we finish photographing the whale?) Has the whale gone silent? Has this track crossed paths with another?
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This dataset contains acoustic recordings from Directional Frequency Analysis and Recording (DIFAR) sonobuoys that were deployed throughout the 2015 NZ-Aus Antarctic Ecosystems Voyage. During the 42 day voyage 310 sonobuoys were deployed yielding 520 hours of acoustic recordings. Two models of sonobuoys were used during the voyage: 2 were AN/SSQ-53F (Ultra Electronics: SonobuoyTechSystems, USA) and 308 were re-lifed AN/SSQ-955-HIDAR (deployed in DIFAR compatibility mode; Ultra Electronics Sonar Systems, UK). A total team of four dedicated acousticians monitored round-the-clock for blue whales and in all weather conditions. After deployment, sonobuoys sent acoustic and directional data 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 pre-amplifier (Minicircuits Inc. ZX60-33LN-S+) mounted on the mast of the ship at a height of 21 m. The preamplifier was connected to a power splitter via LMR400 cable and signals were received with two WiNRaDiO G39WSBe sonobuoy receivers. The radio signal from sonobuoys was adequate for monitoring and localization out to a typical range of 12-15 nmi. Received signals were digitised via the instrument inputs of a Fireface UFX sound board (RME Fireface; RME Inc.) with a gain set to 20 dB (8.396 V peak-peak voltage limits). Digitised signals were recorded on a personal computer as two-channel 48 kHz 24-bit WAV audio files using the software program PAMGuard (Gillespie et al. 2008). Directional calibration The magnetic compass in each sonobuoy was calibrated/validated upon deployment as described by Miller et al. (2015, 2016). Calibration procedure involved measuring the mean bearing error and standard deviation of errors between the GPS-derived bearing from the sonobuoy to the ship and the magnetic bearing to the ship noise detected by the sonobuoy. 15-20 bearings were used for each calibration as the ship steamed directly away from the deployment location. Intensity calibration Obtaining calibrated intensity measurements from sonobuoys not only requires knowledge of the sensitivity of the hydrophone, but also the calibration parameters of the radio transmitter and radio receiver. Throughout the voyage, a hydrophone sensitivity of -122 dB re 1 V/micro Pa was applied to recordings via the Hydrophone Array Manager in PAMGuard. This value is defined in the DIFAR specification as the reference intensity at 100 Hz that will generate a frequency deviation of 25 kHz (Maranda 2001), thus the specification combines the hydrophone sensitivity and transmitter calibration. In line with manufacturers specifications, the WiNRADiO G39 WSB had a measured voltage response of 1 V-peak–peak (approximately -3 dB) at 25 kHz frequency deviation (Miller et al. 2014), and this was subtracted from the hydrophone sensitivity to yield an total combined factor of 125 dB re 1 V/µPa. The gain of the instrument input on the Fireface UFX was set to 20 dB, yielding a maximum voltage input voltage range of 8.36 V peak–peak. These calibration settings, along with the shaped filter response provided by Greene et al. (2004) make it possible to obtain calibrated pressure amplitude from the recorded WAV audio files. 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 (PamguardBlueWhale-2015-02-03.mdb). A written sonobuoy deployment log (Sonobuoy deployment logbook - 2015 Tangaroa.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 (Acoustic event log) Aural and visual monitoring of audio and spectrograms from each sonobuoy was conducted for each sonobuoy deployment. Two different spectrograms were typically viewed, one for low-frequency sounds with the following parameters: 250 Hz sample rate; 256 sample FFT; 32 sample advance between time slices. The other spectrogram was used to view mid-frequency sounds with the following parameters: 8000 Hz sample rate; 1024 sample FFT; 128 sample advance between time slices. Monitoring was typically conducted in real-time as data were being acquired, and the intensity scale of the spectrogram was adjusted by the operator to suit the ambient noise conditions. Detections from marine mammals, ice, and other sources and were detected and classified manually, and their time and frequency bounds were marked on the PAMGuard spectrogram. The PAMGuard DIFAR module (Miller et al. 2016) was then used to measure the direction of arrival and intensity of suitable calls from a variety of species such as tonal, frequency-modulated, and pulsed calls of baleen whales; and also some whistles from toothed whales. Echolocation clicks from sperm whales and any other short broadband sounds were noted in the PAMGuard UserInput (free form notes stored in the PAMGuard Microsoft Access database), but were not able to be localised with the DIFAR module due to limitations inherent in directional sensors in the sonobuoy. Each detection, bearing, and intensity measurement were saved within PAMGuard binaryStorage files in addition to the DIFAR_Localisation table of the PAMGuard database. In addition to PAMGuard binary files and audio files, the PAMGuard settings and metadata were saved inside the PAMGuard Sqlite database. Parameters for monitoring, recording, directional analysis, and other PAMGuard modules were stored within the PAMGuard database and as stand-alone Pamguard Settings Files (PSF). In addition to recording of Antarctic blue whale song, New Zealand type blue whale song, and blue whale 'D-call' vocalisations, these recordings also contain vocalisations from fin whales, humpback whales, killer whales, sperm whales, as well as low frequency sounds from Antarctic sea ice. Whale tracking log (Written Whale Acoustic Tracking Log - Tangaroa 2015.pdf) During the 2015 Voyage Acousticians also created a written summary of the event log at irregular intervals, typically between 30-60 minutes and this summary comprises the Whale Tracking Log. The acoustician on-duty recorded the average bearings or locations of each calling whale/group in the written Whale Tracking Log when the situation regarding the relative position of tracked whale groups was deemed to have changed. Entries in the written Sonobuoy Tracking Log (on the bench in the acoustics workstation) included the location of different whale groups and total number of different whale groups heard during that time interval. 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. Maranda, B.H., 2001. Calibration Factors for DIFAR Processing, Miller, B.S. et al., 2014. Accuracy and precision of DIFAR localisation systems: Calibrations and comparative measurements from three SORP voyages. Submitted to the Scientific Committee 65b of the International Whaling Commission, Bled, Slovenia. SC/65b/SH08, p.14. 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/. Raw Audio Files: DS05_Sonobuoy_audio Sonobuoy deployment log: DS07_Sonobuoy_deployment_log Acoustic event log: DS08_Acoustic_event_log Whale tracking log: DS09_Whale_tracking_log
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The sonobuoy deployment log is a csv file that contains metadata on the deployment of sonobuoys deployed during the 2013 Antarctic Blue Whale Voyage. The first row contains column headers, while each subsequent row contains deployment information for a single sonobuoy. Data that were recorded during each sonobuoy deployment are: buoyID: Buoy ID number is the sequential number of the buoy starting at 1 for the first buoy of the trip. startDate: Date (UTC) at the start of the sonobuoy deployment (YYYY-MM-DD) startTime: Time (UTC) at the start of the sonobuoy deployment (HH:MM:SS) 2 digit hour with 24 hour clock and leading zero. stopDate: Date (UTC) at the end of the sonobuoy deployment (YYYY-MM-DD). While the recording is in progress this should be 1,2 4 or 8 hours after the startTime based on sonobuoy setting. stopTime: Time (UTC) at the end of the sonobuoy deployment (HH:MM:SS). While the recording is in progress this should be 1,2 4 or 8 hours after the startTime based on the sonobuoy setting. lat: Latitude of deployment in decimal degrees. Southern hemisphere latitudes should be negative. long: Longitude of deployment in decimal degrees. Western hemisphere longitudes should be negative. alt: Depth of the sonobuoy deployment in metres. For DIFAR sonobuoys either 30, 120 or 300. recordingChannel: This is the channel number within the recorded wav-file that contains audio from this buoy as would be reported by Matlab. Channel numbers start at 1 (1-indexed) so usually this will be 1, 2 or 3. magVariation: The magnetic variation in degrees. Positive declination is East, negative is West. At the start of a recording this will be entered from a chart. As the recording progresses, this should be updated by measuring the bearing to the vessel. sonobuoyType: The an/ssq designation for the sonobuoy. Usually 53B, 53D, 53F, HIDAR, 57A/B, or 36Q. receiver: The type and serial number of the calibrated radio receiver (WinRadio) used to receive the VHF signal. (wr15725, wr17274, wr15274, or wr15273) preamp: The (unitless) gain in dB of any preamplifier (including the instrument preamp from the Fireface UFX). Usually 10 or 20 dB. adc: The analog-to-digital converter (adc) used to digitize the audio. This is the sound card name and gain. All data were recorded on an RME Fireface UFX, so Ufx10 would be the RME Fireface UFX with a gain of 10 dB. vhfFreq: The VHF channel number used to receive the sonobuoys. Sonobuoys have 99 pre-set VHF channels between