"comment":"The number of tx_beams in this beam group"
"comment":"The number of transmit beams in this beam group"
},
{
"name":"backscatter_sample",
...
...
@@ -1870,7 +1870,7 @@
"obligation":"M",
"comment":"Timestamp at which each ping occurred.",
"dims":[
"ping_time"
"ping_timeDim"
],
"type":"uint64",
"attributes":[
...
...
@@ -1936,8 +1936,8 @@
"obligation":"MA",
"comment":"Imaginary part of backscatter measurements. Each element in the 2D matrix is a variable length vector (of type sample_t) that contains the samples for that beam and ping time.",
"dims":[
"ping_time",
"beam"
"ping_timeDim",
"beamDim"
],
"type":"sample_byte_t",
"attributes":[
...
...
@@ -2157,6 +2157,159 @@
}
]
},
{
"name":"tx_beam_direction_x",
"obligation":"M",
"comment":"The _x_-axis coordinate of a unit vector in the tx_beam direction for each beam and ping in the FACS coordinate system (ie relative to the vertical)",
"dims":[
"ping_timeDim",
"beamDim"
],
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"_x_-component of the vector that gives the pointing direction of the tx_beam, in sonar beam coordinate system"
},
{
"name":"crs",
"value":"FACS"
},
{
"name":"valid_range",
"value":"-1.0f, 1.0f",
"type":"float"
}
]
},
{
"name":"tx_beam_direction_y",
"obligation":"M",
"comment":"The _y_-axis coordinate of a unit vector in the beam direction for each tx_beam and ping, in the FACS coordinate system (ie relative to the vertical)",
"dims":[
"ping_timeDim",
"beamDim"
],
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"_y_-component of the vector that gives the pointing direction of the tx_beam, in the FACS coordinate system (ie relative to the vertical)"
},
{
"name":"valid_range",
"value":"-1.0f, 1.0f",
"type":"float"
},
{
"name":"crs",
"value":"FACS"
}
]
},
{
"name":"tx_beam_direction_z",
"obligation":"M",
"comment":"The _z_-axis coordinate of a unit vector in the tx_beam direction for each beam and ping, in the FACS coordinate system (ie relative to the vertical)",
"dims":[
"ping_timeDim",
"beamDim"
],
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"_z_-component of the vector that gives the pointing direction of the tx_beam, in the FACS coordinate system (ie relative to the vertical)"
},
{
"name":"valid_range",
"value":"-1.0f, 1.0f",
"type":"float"
},
{
"name":"crs",
"value":"FACS"
}
]
},
{
"name":"tx_tilt_angle",
"obligation":"M",
"comment":"the along ship steering angle of beam relative the transducer face in TACS coordinate system",
"dims":[
"ping_timeDim",
"tx_beamDim"
],
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"the along ship steering angle of beam relative the transducer face in TACS coordinate system"
},
{
"name":"crs",
"value":"TACS"
},
{
"name":"valid_range",
"value":"-90.0f, 90.0f",
"type":"float"
},
{
"name":"units",
"value":"arc_degree"
}
]
},
{
"name":"tx_transducer_zdepth",
"obligation":"O",
"comment":"Tx transducer depth in meters below waterline, at time of midpoint of first tx pulse. For the tx array (head) used by this RX-fan. Use depth of TX1 to move depth point (XYZ) from water line to transducer (reference point of old datagram format). ",
"dims":[
"ping_timeDim"
],
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"Tx transducer depth below waterline"
},
{
"name":"units",
"value":"m"
}
]
},
{
"name":"beam_stabilisation",
"obligation":"M",
"comment":"Indicates whether or not sonar beams have been compensated for platform motion.",
"dims":[
"ping_timeDim"
],
"type":"beam_stabilisation_t",
"attributes":[
{
"name":"long_name",
"value":"Beam stabilisation applied (or not)"
}
]
},
{
"name":"beam_type",
"obligation":"M",
"comment":"Type of beam.",
"dims":[
"ping_timeDim"
],
"type":"beam_t",
"attributes":[
{
"name":"long_name",
"value":"Type of beam"
}
]
},
{
"name":"equivalent_beam_angle",
"obligation":"M",
...
...
@@ -2274,7 +2427,26 @@
{
"name":"sample_time_offset",
"obligation":"M",
"comment":"Time offset applied to sample time-stamps and intended for applying a range correction (e.g. as caused by signal processing delays). Positive values reduce the calculated range to a sample. For multibeam echo sounder, this match the transmit sector time delay",
"comment":"Time offset applied to sample time-stamps and intended for applying a range correction (e.g. as caused by signal processing delays). Positive values reduce the calculated range to a sample.",
"dims":[
"ping_timeDim"
],
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"Time offset that is subtracted from the timestamp of each sample"
},
{
"name":"units",
"value":"s"
}
]
},
{
"name":"transmit_time_delay",
"obligation":"O",
"comment":"Time delay for each transmit beam between the ping time and the transmit time",
"dims":[
"ping_timeDim",
"tx_beamDim"
...
...
@@ -2283,7 +2455,7 @@
"attributes":[
{
"name":"long_name",
"value":"Time offset that is subtracted from the timestamp of each sample (For multibeam echo sounder, this match the transmit sector time delay)"
"value":"Time delay for each transmit beam between the ping time and the transmit time"
},
{
"name":"units",
...
...
@@ -2292,22 +2464,26 @@
]
},
{
"name":"sample_start_offset",
"name":"blanking_interval",
"obligation":"M",
"comment":"number of sample before the start of sample recording, this amount of empty sample should be added to the water column data",
"comment":"Time between first sample in data array and the first valid values.",
"dims":[
"ping_timeDim",
"beamDim"
],
"type":"int",
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"number of sample before the start of sample recording"
"value":"Time between first recorded sample in data array and the first valid value "
},
{
"name":"units",
"value":"s"
},
{
"name":"valid_min",
"value":"0"
"value":"0.0"
}
]
},
...
...
@@ -2355,7 +2531,8 @@
"obligation":"O",
"comment":"Estimated bandwidth of the transmitted pulse. For CW pulses, this is a function of the pulse duration and frequency. For FM pulses, this will be close to the difference between transmit_frequency_start and transmit_frequency_stop.",
"dims":[
"ping_timeDim"
"ping_timeDim",
"tx_beamDim"
],
"type":"float",
"attributes":[
...
...
@@ -2379,7 +2556,8 @@
"obligation":"MA",
"comment":"Equivalent duration of the transmit pulse. This is the square pulse containing the same energy as the actual transmitted pulse. Necessary for both type 1 and 2 conversion equations.",
"dims":[
"ping_timeDim"
"ping_timeDim",
"tx_beamDim"
],
"type":"float",
"attributes":[
...
...
@@ -2403,7 +2581,8 @@
"obligation":"M",
"comment":"Nominal duration of the transmit pulse. This is not the equivalent pulse duration.",
"dims":[
"ping_timeDim"
"ping_timeDim",
"tx_beamDim"
],
"type":"float",
"attributes":[
...
...
@@ -2428,7 +2607,7 @@
"comment":"Frequency at the start of the transmit pulse. The beam dimension can be omitted, in which case the value apples to all beams in the ping.",
"dims":[
"ping_timeDim",
"beamDim"
"tx_beamDim"
],
"type":"float",
"attributes":[
...
...
@@ -2457,7 +2636,7 @@
"comment":"Frequency at the end of the transmit pulse. The beam dimension can be omitted, in which case the value apples to all beams in the ping.",
"dims":[
"ping_timeDim",
"beamDim"
"tx_beamDim"
],
"type":"float",
"attributes":[
...
...
@@ -2613,7 +2792,34 @@
}
]
},
{
"name":"sound_speed_at_transducer",
"obligation":"O",
"comment":"Sound speed at tx transducer depth at ping time",
"dims":[
"ping_timeDim"
],
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"Indicative sound speed at ping time and transducer depth"
},
{
"name":"units",
"value":"m/s"
},
{
"name":"valid_min",
"value":"0.0",
"type":"float"
},
{
"name":"standard_name",
"value":"speed_of_sound_in_sea_water"
}
]
},
{
"name":"platform_latitude",
"obligation":"M",
...
...
@@ -2693,7 +2899,7 @@
},
{
"name":"valid_range",
"value":"0, 360.0",
"value":"0f, 360.0f",
"type":"float"
}
]
...
...
@@ -2725,7 +2931,7 @@
},
{
"name":"valid_range",
"value":"−90.0, 90.0",
"value":"-90.0f, 90.0f",
"type":"float"
}
]
...
...
@@ -2790,34 +2996,7 @@
}
]
},
{
"name":"sound_speed_at_transducer",
"obligation":"O",
"comment":"Sound speed at tx transducer depth at the mid-time of emission of the first tx pulse",
"dims":[
"ping_timeDim"
],
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"Indicative sound speed at tx time and depth"
},
{
"name":"units",
"value":"m/s"
},
{
"name":"valid_min",
"value":"0.0",
"type":"float"
},
{
"name":"standard_name",
"value":"speed_of_sound_in_sea_water"
}
]
},
{
"name":"swath_dynamic_draught",
"obligation":"M",
...
...
@@ -2887,74 +3066,7 @@
}
]
},
{
"name":"tx_center_frequency",
"obligation":"M",
"comment":"center frequency of transmit sector",
"dims":[
"ping_timeDim",
"tx_beamDim"
],
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"center frequency of transmit sector"
},
{
"name":"units",
"value":"Hz"
}
]
},
{
"name":"tx_tilt_angle",
"obligation":"M",
"comment":"the along ship steering angle of beam relative the transducer face in TACS coordinate system",
"dims":[
"ping_timeDim",
"tx_beamDim"
],
"type":"float",
"attributes":[
{
"name":"long_name",
"value":"the along ship steering angle of beam relative the transducer face in TACS coordinate system"
},
{
"name":"crs",
"value":"TACS"
},
{
"name":"valid_range",
"value":"-90.0f, 90.0f",
"type":"float"
},
{
"name":"units",
"value":"arc_degree"
}
]
},
{
"name":"tx_transducer_zdepth",
"obligation":"O",
"comment":"Tx transducer depth in meters below waterline, at time of midpoint of first tx pulse. For the tx array (head) used by this RX-fan. Use depth of TX1 to move depth point (XYZ) from water line to transducer (reference point of old datagram format). ",
