• <xarray.Dataset>
      Dimensions:  ()
      Data variables:
          *empty*
      Attributes:
          conventions:                 CF-1.7, SONAR-netCDF4-1.0, ACDD-1.3
          keywords:                    EK60
          sonar_convention_authority:  ICES
          sonar_convention_name:       SONAR-netCDF4
          sonar_convention_version:    1.0
          summary:                     EK60 raw file s3://ncei-wcsd-archive/data/ra...
          title:                       2017 Pacific Hake Acoustic Trawl Survey
          date_created:                2017-07-28T18:16:19Z
          survey_name:                 
      xarray.Dataset
          • conventions :
            CF-1.7, SONAR-netCDF4-1.0, ACDD-1.3
            keywords :
            EK60
            sonar_convention_authority :
            ICES
            sonar_convention_name :
            SONAR-netCDF4
            sonar_convention_version :
            1.0
            summary :
            EK60 raw file s3://ncei-wcsd-archive/data/raw/Bell_M._Shimada/SH1707/EK60/Summer2017-D20170728-T181619.raw from the 2017 Pacific Hake Acoustic Trawl Survey, converted to a SONAR-netCDF4 file using echopype.
            title :
            2017 Pacific Hake Acoustic Trawl Survey
            date_created :
            2017-07-28T18:16:19Z
            survey_name :

        • <xarray.Dataset>
          Dimensions:                 (frequency: 3, ping_time: 529)
          Coordinates:
            * frequency               (frequency) float64 1.8e+04 3.8e+04 1.2e+05
            * ping_time               (ping_time) datetime64[ns] 2017-07-28T18:16:19.31...
          Data variables:
              absorption_indicative   (frequency, ping_time) float64 0.002822 ... 0.03259
              sound_speed_indicative  (frequency, ping_time) float64 1.481e+03 ... 1.48...
          xarray.Dataset
            • frequency: 3
            • ping_time: 529
            • frequency
              (frequency)
              float64
              1.8e+04 3.8e+04 1.2e+05
              units :
              Hz
              long_name :
              Transducer frequency
              valid_min :
              0.0
              array([ 18000.,  38000., 120000.])
            • ping_time
              (ping_time)
              datetime64[ns]
              2017-07-28T18:16:19.313999872 .....
              axis :
              T
              long_name :
              Timestamps for NMEA position datagrams
              standard_name :
              time
              array(['2017-07-28T18:16:19.313999872', '2017-07-28T18:16:22.143000064',
                     '2017-07-28T18:16:24.962999808', ..., '2017-07-28T18:41:23.292000256',
                     '2017-07-28T18:41:25.949000192', '2017-07-28T18:41:28.597000192'],
                    dtype='datetime64[ns]')
            • absorption_indicative
              (frequency, ping_time)
              float64
              0.002822 0.002822 ... 0.03259
              long_name :
              Indicative acoustic absorption
              units :
              dB/m
              valid_min :
              0.0
              array([[0.00282171, 0.00282171, 0.00282171, ..., 0.00282171, 0.00282171,
                      0.00282171],
                     [0.00985526, 0.00985526, 0.00985526, ..., 0.00985526, 0.00985526,
                      0.00985526],
                     [0.03259379, 0.03259379, 0.03259379, ..., 0.03259379, 0.03259379,
                      0.03259379]])
            • sound_speed_indicative
              (frequency, ping_time)
              float64
              1.481e+03 1.481e+03 ... 1.481e+03
              long_name :
              Indicative sound speed
              standard_name :
              speed_of_sound_in_sea_water
              units :
              m/s
              valid_min :
              0.0
              array([[1480.62597656, 1480.62597656, 1480.62597656, ..., 1480.62597656,
                      1480.62597656, 1480.62597656],
                     [1480.62597656, 1480.62597656, 1480.62597656, ..., 1480.62597656,
                      1480.62597656, 1480.62597656],
                     [1480.62597656, 1480.62597656, 1480.62597656, ..., 1480.62597656,
                      1480.62597656, 1480.62597656]])

        • <xarray.Dataset>
          Dimensions:        (location_time: 2165, frequency: 3, ping_time: 529)
          Coordinates:
            * location_time  (location_time) datetime64[ns] 2017-07-28T18:16:21.4759997...
            * frequency      (frequency) float64 1.8e+04 3.8e+04 1.2e+05
            * ping_time      (ping_time) datetime64[ns] 2017-07-28T18:16:19.313999872 ....
          Data variables:
              latitude       (location_time) float64 dask.array<chunksize=(2165,), meta=np.ndarray>
              longitude      (location_time) float64 dask.array<chunksize=(2165,), meta=np.ndarray>
              sentence_type  (location_time) <U3 dask.array<chunksize=(2165,), meta=np.ndarray>
              pitch          (frequency, ping_time) float64 dask.array<chunksize=(3, 529), meta=np.ndarray>
              roll           (frequency, ping_time) float64 dask.array<chunksize=(3, 529), meta=np.ndarray>
              heave          (frequency, ping_time) float64 dask.array<chunksize=(3, 529), meta=np.ndarray>
              water_level    (frequency, ping_time) float64 dask.array<chunksize=(3, 529), meta=np.ndarray>
          Attributes:
              platform_type:       Research vessel
              platform_name:       Bell M. Shimada
              platform_code_ICES:  315
          xarray.Dataset
            • location_time: 2165
            • frequency: 3
            • ping_time: 529
            • location_time
              (location_time)
              datetime64[ns]
              2017-07-28T18:16:21.475999744 .....
              axis :
              T
              long_name :
              Timestamps for NMEA datagrams
              standard_name :
              time
              array(['2017-07-28T18:16:21.475999744', '2017-07-28T18:16:21.635000320',
                     '2017-07-28T18:16:22.168999936', ..., '2017-07-28T18:41:29.893000192',
                     '2017-07-28T18:41:31.143000064', '2017-07-28T18:41:31.301000192'],
                    dtype='datetime64[ns]')
            • frequency
              (frequency)
              float64
              1.8e+04 3.8e+04 1.2e+05
              units :
              Hz
              long_name :
              Transducer frequency
              valid_min :
              0.0
              array([ 18000.,  38000., 120000.])
            • ping_time
              (ping_time)
              datetime64[ns]
              2017-07-28T18:16:19.313999872 .....
              axis :
              T
              long_name :
              Timestamps for position datagrams
              standard_name :
              time
              array(['2017-07-28T18:16:19.313999872', '2017-07-28T18:16:22.143000064',
                     '2017-07-28T18:16:24.962999808', ..., '2017-07-28T18:41:23.292000256',
                     '2017-07-28T18:41:25.949000192', '2017-07-28T18:41:28.597000192'],
                    dtype='datetime64[ns]')
            • latitude
              (location_time)
              float64
              dask.array<chunksize=(2165,), meta=np.ndarray>
              long_name :
              Platform latitude
              standard_name :
              latitude
              units :
              degrees_north
              valid_range :
              (-90.0, 90.0)
              Array Chunk
              Bytes 16.91 kiB 16.91 kiB
              Shape (2165,) (2165,)
              Count 2 Tasks 1 Chunks
              Type float64 numpy.ndarray
              2165 1
            • longitude
              (location_time)
              float64
              dask.array<chunksize=(2165,), meta=np.ndarray>
              long_name :
              Platform longitude
              standard_name :
              longitude
              units :
              degrees_east
              valid_range :
              (-180.0, 180.0)
              Array Chunk
              Bytes 16.91 kiB 16.91 kiB
              Shape (2165,) (2165,)
              Count 2 Tasks 1 Chunks
              Type float64 numpy.ndarray
              2165 1
            • sentence_type
              (location_time)
              <U3
              dask.array<chunksize=(2165,), meta=np.ndarray>
              Array Chunk
              Bytes 25.37 kiB 25.37 kiB
              Shape (2165,) (2165,)
              Count 2 Tasks 1 Chunks
              Type numpy.ndarray
              2165 1
            • pitch
              (frequency, ping_time)
              float64
              dask.array<chunksize=(3, 529), meta=np.ndarray>
              long_name :
              Platform pitch
              standard_name :
              platform_pitch_angle
              units :
              arc_degree
              valid_range :
              (-90.0, 90.0)
              Array Chunk
              Bytes 12.40 kiB 12.40 kiB
              Shape (3, 529) (3, 529)
              Count 2 Tasks 1 Chunks
              Type float64 numpy.ndarray
              529 3
            • roll
              (frequency, ping_time)
              float64
              dask.array<chunksize=(3, 529), meta=np.ndarray>
              long_name :
              Platform roll
              standard_name :
              platform_roll_angle
              units :
              arc_degree
              valid_range :
              (-90.0, 90.0)
              Array Chunk
              Bytes 12.40 kiB 12.40 kiB
              Shape (3, 529) (3, 529)
              Count 2 Tasks 1 Chunks
              Type float64 numpy.ndarray
              529 3
            • heave
              (frequency, ping_time)
              float64
              dask.array<chunksize=(3, 529), meta=np.ndarray>
              long_name :
              Platform heave
              standard_name :
              platform_heave_angle
              units :
              arc_degree
              valid_range :
              (-90.0, 90.0)
              Array Chunk
              Bytes 12.40 kiB 12.40 kiB
              Shape (3, 529) (3, 529)
              Count 2 Tasks 1 Chunks
              Type float64 numpy.ndarray
              529 3
            • water_level
              (frequency, ping_time)
              float64
              dask.array<chunksize=(3, 529), meta=np.ndarray>
              long_name :
              z-axis distance from the platform coordinate system origin to the sonar transducer
              units :
              m
              Array Chunk
              Bytes 12.40 kiB 12.40 kiB
              Shape (3, 529) (3, 529)
              Count 2 Tasks 1 Chunks
              Type float64 numpy.ndarray
              529 3
          • platform_type :
            Research vessel
            platform_name :
            Bell M. Shimada
            platform_code_ICES :
            315

        • <xarray.Dataset>
          Dimensions:        (location_time: 22037)
          Coordinates:
            * location_time  (location_time) datetime64[ns] 2017-07-28T18:16:19.3140003...
          Data variables:
              NMEA_datagram  (location_time) <U73 '$SDVLW,5050.149,N,5050.149,N' ... '$...
          Attributes:
              description:  All NMEA sensor datagrams
          xarray.Dataset
            • location_time: 22037
            • location_time
              (location_time)
              datetime64[ns]
              2017-07-28T18:16:19.314000384 .....
              axis :
              T
              long_name :
              Timestamps for NMEA datagrams
              standard_name :
              time
              array(['2017-07-28T18:16:19.314000384', '2017-07-28T18:16:20.896000000',
                     '2017-07-28T18:16:20.995999744', ..., '2017-07-28T18:41:32.515999744',
                     '2017-07-28T18:41:32.616000000', '2017-07-28T18:41:32.401999872'],
                    dtype='datetime64[ns]')
            • NMEA_datagram
              (location_time)
              <U73
              '$SDVLW,5050.149,N,5050.149,N' ....
              long_name :
              NMEA datagram
              array(['$SDVLW,5050.149,N,5050.149,N', '$INHDT,268.8,T', '$INHDT,268.8,T',
                     ..., '$INHDT,270.9,T', '$INHDT,270.9,T',
                     '$GPDTM,W84,,0000.0000,N,00000.0000,E,,W84'], dtype='<U73')
          • description :
            All NMEA sensor datagrams

        • <xarray.Dataset>
          Dimensions:  ()
          Data variables:
              *empty*
          Attributes:
              conversion_software_name:     echopype
              conversion_software_version:  0.5.4.dev30+g927d2cf.d20211110
              conversion_time:              2021-12-08T05:23:19Z
              src_filenames:                s3://ncei-wcsd-archive/data/raw/Bell_M._Shi...
              duplicate_ping_times:         0
          xarray.Dataset
              • conversion_software_name :
                echopype
                conversion_software_version :
                0.5.4.dev30+g927d2cf.d20211110
                conversion_time :
                2021-12-08T05:23:19Z
                src_filenames :
                s3://ncei-wcsd-archive/data/raw/Bell_M._Shimada/SH1707/EK60/Summer2017-D20170728-T181619.raw
                duplicate_ping_times :
                0

            • <xarray.Dataset>
              Dimensions:  ()
              Data variables:
                  *empty*
              Attributes:
                  sonar_manufacturer:      Simrad
                  sonar_model:             ER60
                  sonar_serial_number:
                  sonar_software_name:
                  sonar_software_version:  2.4.3
                  sonar_type:              echosounder
              xarray.Dataset
                  • sonar_manufacturer :
                    Simrad
                    sonar_model :
                    ER60
                    sonar_serial_number :
                    sonar_software_name :
                    sonar_software_version :
                    2.4.3
                    sonar_type :
                    echosounder

                • <xarray.Dataset>
                  Dimensions:                         (frequency: 3, ping_time: 529, range_bin: 3957)
                  Coordinates:
                    * frequency                       (frequency) float64 1.8e+04 3.8e+04 1.2e+05
                    * ping_time                       (ping_time) datetime64[ns] 2017-07-28T18:...
                    * range_bin                       (range_bin) int64 0 1 2 3 ... 3954 3955 3956
                  Data variables: (12/30)
                      channel_id                      (frequency) <U37 'GPT  18 kHz 009072058c8...
                      beam_type                       (frequency) int64 1 1 1
                      beamwidth_receive_alongship     (frequency) float64 10.9 6.81 6.58
                      beamwidth_receive_athwartship   (frequency) float64 10.82 6.85 6.52
                      beamwidth_transmit_alongship    (frequency) float64 10.9 6.81 6.58
                      beamwidth_transmit_athwartship  (frequency) float64 10.82 6.85 6.52
                      ...                              ...
                      data_type                       (frequency, ping_time) float64 3.0 ... 3.0
                      count                           (frequency, ping_time) float64 3.957e+03 ...
                      offset                          (frequency, ping_time) float64 0.0 ... 0.0
                      transmit_mode                   (frequency, ping_time) float64 0.0 ... 0.0
                      angle_athwartship               (frequency, ping_time, range_bin) float64 ...
                      angle_alongship                 (frequency, ping_time, range_bin) float64 ...
                  Attributes:
                      beam_mode:              vertical
                      conversion_equation_t:  type_3
                  xarray.Dataset
                    • frequency: 3
                    • ping_time: 529
                    • range_bin: 3957
                    • frequency
                      (frequency)
                      float64
                      1.8e+04 3.8e+04 1.2e+05
                      long_name :
                      Transducer frequency
                      standard_name :
                      sound_frequency
                      units :
                      Hz
                      valid_min :
                      0.0
                      array([ 18000.,  38000., 120000.])
                    • ping_time
                      (ping_time)
                      datetime64[ns]
                      2017-07-28T18:16:19.313999872 .....
                      long_name :
                      Timestamp of each ping
                      standard_name :
                      time
                      axis :
                      T
                      array(['2017-07-28T18:16:19.313999872', '2017-07-28T18:16:22.143000064',
                             '2017-07-28T18:16:24.962999808', ..., '2017-07-28T18:41:23.292000256',
                             '2017-07-28T18:41:25.949000192', '2017-07-28T18:41:28.597000192'],
                            dtype='datetime64[ns]')
                    • range_bin
                      (range_bin)
                      int64
                      0 1 2 3 4 ... 3953 3954 3955 3956
                      long_name :
                      Along-range bin (sample) number, base 0
                      array([   0,    1,    2, ..., 3954, 3955, 3956])
                    • channel_id
                      (frequency)
                      <U37
                      'GPT 18 kHz 009072058c8d 1-1 ES...
                      array(['GPT  18 kHz 009072058c8d 1-1 ES18-11',
                             'GPT  38 kHz 009072058146 2-1 ES38B',
                             'GPT 120 kHz 00907205a6d0 4-1 ES120-7C'], dtype='<U37')
                    • beam_type
                      (frequency)
                      int64
                      1 1 1
                      long_name :
                      type of transducer (0-single, 1-split)
                      array([1, 1, 1])
                    • beamwidth_receive_alongship
                      (frequency)
                      float64
                      10.9 6.81 6.58
                      long_name :
                      Half power one-way receive beam width along alongship axis of beam
                      units :
                      arc_degree
                      valid_range :
                      (0.0, 360.0)
                      array([10.89999962,  6.80999994,  6.57999992])
                    • beamwidth_receive_athwartship
                      (frequency)
                      float64
                      10.82 6.85 6.52
                      long_name :
                      Half power one-way receive beam width along athwartship axis of beam
                      units :
                      arc_degree
                      valid_range :
                      (0.0, 360.0)
                      array([10.81999969,  6.8499999 ,  6.51999998])
                    • beamwidth_transmit_alongship
                      (frequency)
                      float64
                      10.9 6.81 6.58
                      long_name :
                      Half power one-way transmit beam width along alongship axis of beam
                      units :
                      arc_degree
                      valid_range :
                      (0.0, 360.0)
                      array([10.89999962,  6.80999994,  6.57999992])
                    • beamwidth_transmit_athwartship
                      (frequency)
                      float64
                      10.82 6.85 6.52
                      long_name :
                      Half power one-way transmit beam width along athwartship axis of beam
                      units :
                      arc_degree
                      valid_range :
                      (0.0, 360.0)
                      array([10.81999969,  6.8499999 ,  6.51999998])
                    • beam_direction_x
                      (frequency)
                      float64
                      0.0 0.0 0.0
                      long_name :
                      x-component of the vector that gives the pointing direction of the beam, in sonar beam coordinate system
                      units :
                      1
                      valid_range :
                      (-1.0, 1.0)
                      array([0., 0., 0.])
                    • beam_direction_y
                      (frequency)
                      float64
                      0.0 0.0 0.0
                      long_name :
                      y-component of the vector that gives the pointing direction of the beam, in sonar beam coordinate system
                      units :
                      1
                      valid_range :
                      (-1.0, 1.0)
                      array([0., 0., 0.])
                    • beam_direction_z
                      (frequency)
                      float64
                      0.0 0.0 0.0
                      long_name :
                      z-component of the vector that gives the pointing direction of the beam, in sonar beam coordinate system
                      units :
                      1
                      valid_range :
                      (-1.0, 1.0)
                      array([0., 0., 0.])
                    • angle_offset_alongship
                      (frequency)
                      float64
                      -0.18 -0.08 -0.05
                      long_name :
                      electrical alongship angle of the transducer
                      array([-0.18000001, -0.08      , -0.05      ])
                    • angle_offset_athwartship
                      (frequency)
                      float64
                      0.25 0.0 0.37
                      long_name :
                      electrical athwartship angle of the transducer
                      array([0.25, 0.  , 0.37])
                    • angle_sensitivity_alongship
                      (frequency)
                      float64
                      13.89 21.97 23.12
                      long_name :
                      alongship sensitivity of the transducer
                      array([13.89000034, 21.96999931, 23.12000084])
                    • angle_sensitivity_athwartship
                      (frequency)
                      float64
                      13.89 21.97 23.12
                      long_name :
                      athwartship sensitivity of the transducer
                      array([13.89000034, 21.96999931, 23.12000084])
                    • equivalent_beam_angle
                      (frequency)
                      float64
                      -17.37 -21.01 -20.47
                      long_name :
                      Equivalent beam angle
                      units :
                      sr
                      valid_range :
                      (0.0, 12.566370614359172)
                      array([-17.37000084, -21.01000023, -20.46999931])
                    • transducer_offset_x
                      (frequency)
                      float64
                      0.0 0.0 0.0
                      long_name :
                      x-axis distance from the platform coordinate system origin to the sonar transducer
                      units :
                      m
                      array([0., 0., 0.])
                    • transducer_offset_y
                      (frequency)
                      float64
                      0.0 0.0 0.0
                      long_name :
                      y-axis distance from the platform coordinate system origin to the sonar transducer
                      units :
                      m
                      array([0., 0., 0.])
                    • transducer_offset_z
                      (frequency)
                      float64
                      0.0 0.0 0.0
                      long_name :
                      z-axis distance from the platform coordinate system origin to the sonar transducer
                      units :
                      m
                      array([0., 0., 0.])
                    • gain_correction
                      (frequency)
                      float64
                      22.95 26.07 26.55
                      long_name :
                      Gain correction
                      units :
                      dB
                      array([22.95000076, 26.06999969, 26.54999924])
                    • gpt_software_version
                      (frequency)
                      <U6
                      '070413' '070413' '070413'
                      array(['070413', '070413', '070413'], dtype='<U6')
                    • backscatter_r
                      (frequency, ping_time, range_bin)
                      float32
                      15.79 26.34 26.27 ... -159.5 -158.4
                      long_name :
                      Backscatter power
                      units :
                      dB
                      array([[[  15.7923155,   26.340124 ,   26.269571 , ..., -145.34105  ,
                               -146.65805  , -139.60266  ],
                              [  15.7923155,   26.340124 ,   26.269571 , ..., -145.08235  ,
                               -146.19945  , -134.15825  ],
                              [  15.7923155,   26.340124 ,   26.269571 , ..., -141.47234  ,
                               -142.30722  , -146.36407  ],
                              ...,
                              [  15.7923155,   26.340124 ,   26.269571 , ..., -158.02899  ,
                               -148.25728  , -143.49489  ],
                              [  15.7923155,   26.340124 ,   26.269571 , ..., -135.67516  ,
                               -145.0941   , -131.0186   ],
                              [  15.7923155,   26.340124 ,   26.269571 , ..., -134.85204  ,
                               -136.62764  , -132.78246  ]],
                      
                             [[  17.379778 ,   26.72817  ,   27.175013 , ..., -151.70265  ,
                               -155.86534  , -161.45085  ],
                              [  17.379778 ,   26.72817  ,   27.175013 , ..., -163.59099  ,
                               -162.27399  , -161.35678  ],
                              [  17.379778 ,   26.72817  ,   27.175013 , ..., -155.99469  ,
                               -147.63405  , -154.08972  ],
                      ...
                              [  17.379778 ,   26.72817  ,   27.175013 , ..., -145.42336  ,
                               -144.48264  , -146.96378  ],
                              [  17.379778 ,   26.72817  ,   27.175013 , ..., -145.67029  ,
                               -149.93881  , -147.42238  ],
                              [  17.379778 ,   26.72817  ,   27.175013 , ..., -150.23277  ,
                               -150.35037  , -152.79623  ]],
                      
                             [[  12.417487 ,   18.073559 ,   18.050041 , ..., -180.3593   ,
                               -160.2632   , -163.3558   ],
                              [  12.417487 ,   18.073559 ,   18.0618   , ..., -183.04034  ,
                               -162.48564  , -157.74677  ],
                              [  12.417487 ,   18.073559 ,   18.050041 , ..., -166.00157  ,
                               -167.4009   , -170.03491  ],
                              ...,
                              [  12.417487 ,   18.073559 ,   18.0618   , ..., -169.77621  ,
                               -155.05397  , -162.21518  ],
                              [  12.417487 ,   18.073559 ,   18.0618   , ..., -157.81732  ,
                               -167.87126  , -162.45036  ],
                              [  12.417487 ,   18.073559 ,   18.050041 , ..., -158.89915  ,
                               -159.53413  , -158.37     ]]], dtype=float32)
                    • sample_interval
                      (frequency, ping_time)
                      float64
                      0.000256 0.000256 ... 0.000256
                      long_name :
                      Interval between recorded raw data samples
                      units :
                      s
                      valid_min :
                      0.0
                      array([[0.000256, 0.000256, 0.000256, ..., 0.000256, 0.000256, 0.000256],
                             [0.000256, 0.000256, 0.000256, ..., 0.000256, 0.000256, 0.000256],
                             [0.000256, 0.000256, 0.000256, ..., 0.000256, 0.000256, 0.000256]])
                    • transmit_bandwidth
                      (frequency, ping_time)
                      float64
                      1.574e+03 1.574e+03 ... 3.026e+03
                      long_name :
                      Nominal bandwidth of transmitted pulse
                      units :
                      Hz
                      valid_min :
                      0.0
                      array([[1573.66552734, 1573.66552734, 1573.66552734, ..., 1573.66552734,
                              1573.66552734, 1573.66552734],
                             [2425.1496582 , 2425.1496582 , 2425.1496582 , ..., 2425.1496582 ,
                              2425.1496582 , 2425.1496582 ],
                             [3026.39160156, 3026.39160156, 3026.39160156, ..., 3026.39160156,
                              3026.39160156, 3026.39160156]])
                    • transmit_duration_nominal
                      (frequency, ping_time)
                      float64
                      0.001024 0.001024 ... 0.001024
                      long_name :
                      Nominal bandwidth of transmitted pulse
                      units :
                      s
                      valid_min :
                      0.0
                      array([[0.001024, 0.001024, 0.001024, ..., 0.001024, 0.001024, 0.001024],
                             [0.001024, 0.001024, 0.001024, ..., 0.001024, 0.001024, 0.001024],
                             [0.001024, 0.001024, 0.001024, ..., 0.001024, 0.001024, 0.001024]])
                    • transmit_power
                      (frequency, ping_time)
                      float64
                      2e+03 2e+03 2e+03 ... 250.0 250.0
                      long_name :
                      Nominal transmit power
                      units :
                      W
                      valid_min :
                      0.0
                      array([[2000., 2000., 2000., ..., 2000., 2000., 2000.],
                             [2000., 2000., 2000., ..., 2000., 2000., 2000.],
                             [ 250.,  250.,  250., ...,  250.,  250.,  250.]])
                    • data_type
                      (frequency, ping_time)
                      float64
                      3.0 3.0 3.0 3.0 ... 3.0 3.0 3.0 3.0
                      long_name :
                      recorded data type (1-power only, 2-angle only 3-power and angle)
                      array([[3., 3., 3., ..., 3., 3., 3.],
                             [3., 3., 3., ..., 3., 3., 3.],
                             [3., 3., 3., ..., 3., 3., 3.]])
                    • count
                      (frequency, ping_time)
                      float64
                      3.957e+03 3.957e+03 ... 3.957e+03
                      long_name :
                      Number of samples
                      array([[3957., 3957., 3957., ..., 3957., 3957., 3957.],
                             [3957., 3957., 3957., ..., 3957., 3957., 3957.],
                             [3957., 3957., 3957., ..., 3957., 3957., 3957.]])
                    • offset
                      (frequency, ping_time)
                      float64
                      0.0 0.0 0.0 0.0 ... 0.0 0.0 0.0 0.0
                      long_name :
                      Offset of first sample
                      array([[0., 0., 0., ..., 0., 0., 0.],
                             [0., 0., 0., ..., 0., 0., 0.],
                             [0., 0., 0., ..., 0., 0., 0.]])
                    • transmit_mode
                      (frequency, ping_time)
                      float64
                      0.0 0.0 0.0 0.0 ... 0.0 0.0 0.0 0.0
                      long_name :
                      0 = Active, 1 = Passive, 2 = Test, -1 = Unknown
                      array([[0., 0., 0., ..., 0., 0., 0.],
                             [0., 0., 0., ..., 0., 0., 0.],
                             [0., 0., 0., ..., 0., 0., 0.]])
                    • angle_athwartship
                      (frequency, ping_time, range_bin)
                      float64
                      -3.0 -3.0 -4.0 ... 19.0 54.0 33.0
                      long_name :
                      electrical athwartship angle
                      array([[[  -3.,   -3.,   -4., ...,   46., -103.,  -18.],
                              [  -3.,   -3.,   -4., ...,  -13., -126.,   -2.],
                              [  -3.,   -3.,   -4., ...,    6.,   17.,  -61.],
                              ...,
                              [  -3.,   -3.,   -4., ...,  107., -103.,  112.],
                              [  -3.,   -3.,   -4., ...,   30.,  123.,   33.],
                              [  -3.,   -3.,   -4., ...,   -9.,  -15.,   15.]],
                      
                             [[  -1.,   -2.,   -2., ...,  -37.,  -65., -117.],
                              [  -1.,   -2.,   -2., ...,  -38.,   47., -100.],
                              [  -1.,   -2.,   -2., ...,   11.,   23.,   32.],
                              ...,
                              [  -1.,   -2.,   -2., ...,   13.,   13.,   32.],
                              [  -1.,   -2.,   -2., ...,    4.,   31.,   24.],
                              [  -1.,   -2.,   -2., ...,  -11.,  -42., -104.]],
                      
                             [[  -2.,   -3.,   -3., ...,  122.,  -30.,   -7.],
                              [  -2.,   -3.,   -3., ..., -120.,   81.,    9.],
                              [  -2.,   -3.,   -3., ...,   -2.,   51., -105.],
                              ...,
                              [  -2.,   -3.,   -3., ...,  107.,  -32.,  -20.],
                              [  -2.,   -3.,   -3., ...,  -13.,  -99.,  -39.],
                              [  -2.,   -3.,   -3., ...,   19.,   54.,   33.]]])
                    • angle_alongship
                      (frequency, ping_time, range_bin)
                      float64
                      3.0 2.0 3.0 3.0 ... 51.0 93.0 -27.0
                      long_name :
                      electrical alongship angle
                      array([[[   3.,    2.,    3., ...,  -90.,  -78.,  -29.],
                              [   3.,    2.,    3., ...,   90., -101.,  -70.],
                              [   3.,    2.,    3., ...,   49.,   75.,  105.],
                              ...,
                              [   3.,    2.,    3., ...,  118.,   77.,  -63.],
                              [   3.,    2.,    3., ...,  -55.,  116.,   18.],
                              [   3.,    2.,    3., ...,   -1.,  -46.,  -42.]],
                      
                             [[   0.,    0.,   -1., ...,  -42.,    7., -103.],
                              [   0.,    0.,   -1., ...,   93.,  -76.,   86.],
                              [   0.,   -1.,   -1., ...,  -60.,    9.,   33.],
                              ...,
                              [   0.,   -1.,   -1., ...,   19.,   47.,   64.],
                              [   0.,    0.,   -1., ...,   25.,   -2.,    4.],
                              [   0.,   -1.,   -1., ...,   63.,  -10.,  -14.]],
                      
                             [[  -1.,   -1.,   -1., ..., -122.,  -30., -100.],
                              [  -1.,   -1.,   -1., ...,  118.,   61.,    9.],
                              [  -1.,   -1.,   -1., ...,  109.,   42.,  120.],
                              ...,
                              [  -1.,   -1.,   -1., ...,   88.,    3.,  -71.],
                              [  -1.,   -1.,   -1., ...,   47.,  109.,   70.],
                              [  -1.,   -1.,   -1., ...,   51.,   93.,  -27.]]])
                  • beam_mode :
                    vertical
                    conversion_equation_t :
                    type_3

                • <xarray.Dataset>
                  Dimensions:           (frequency: 3, pulse_length_bin: 5)
                  Coordinates:
                    * frequency         (frequency) float64 1.8e+04 3.8e+04 1.2e+05
                    * pulse_length_bin  (pulse_length_bin) int64 0 1 2 3 4
                  Data variables:
                      sa_correction     (frequency, pulse_length_bin) float64 0.0 -0.7 ... -0.3
                      gain_correction   (frequency, pulse_length_bin) float64 20.3 22.95 ... 26.55
                      pulse_length      (frequency, pulse_length_bin) float64 0.000512 ... 0.00...
                  xarray.Dataset
                    • frequency: 3
                    • pulse_length_bin: 5
                    • frequency
                      (frequency)
                      float64
                      1.8e+04 3.8e+04 1.2e+05
                      units :
                      Hz
                      long_name :
                      Transducer frequency
                      valid_min :
                      0.0
                      array([ 18000.,  38000., 120000.])
                    • pulse_length_bin
                      (pulse_length_bin)
                      int64
                      0 1 2 3 4
                      array([0, 1, 2, 3, 4])
                    • sa_correction
                      (frequency, pulse_length_bin)
                      float64
                      0.0 -0.7 0.0 0.0 ... 0.0 0.0 -0.3
                      array([[ 0.  , -0.7 ,  0.  ,  0.  ,  0.  ],
                             [ 0.  ,  0.  , -0.52,  0.  ,  0.  ],
                             [ 0.  ,  0.  ,  0.  ,  0.  , -0.3 ]])
                    • gain_correction
                      (frequency, pulse_length_bin)
                      float64
                      20.3 22.95 22.9 ... 27.0 27.0 26.55
                      array([[20.299999, 22.950001, 22.9     , 23.      , 23.      ],
                             [24.      , 26.      , 26.07    , 26.5     , 26.5     ],
                             [25.5     , 26.799999, 27.      , 27.      , 26.549999]])
                    • pulse_length
                      (frequency, pulse_length_bin)
                      float64
                      0.000512 0.001024 ... 0.001024
                      array([[5.120e-04, 1.024e-03, 2.048e-03, 4.096e-03, 8.192e-03],
                             [2.560e-04, 5.120e-04, 1.024e-03, 2.048e-03, 4.096e-03],
                             [6.400e-05, 1.280e-04, 2.560e-04, 5.120e-04, 1.024e-03]])