AEON Fine-Scale Acoustic Survey (FSAS)

FSAS datasets are shown by the collection site and date measurements were performed; see associated cruise reports for cruise-specific information on how and when these data were collected. Generally, FSAS grids are composed of 4 to 5 line transects, with the survey grid centered on bottom-lander at the given AEON site. Transducer depth is set to 1 m below the surface, the approximate depth at which the towfish (to which the transducers were mounted) was towed.Each .csv file is the survey data at a single frequency, for all transect lines. The naming convention of each file is as follows, with periods separating each component:<br>Date = start date (2022.01.08)Cruise = ship name (Warren, Beast, etc.)<br>Site = three letter site code (WIB, etc.)FSAS number = Assigned FSAS number per cruise, as listed in cruise log (FSAS1)<br>Freq = three digit frequency (120kHz)<br>Export bin dimensions = 005mvert_100mhorz<br>Each .csv contains the following variables:<br>Process ID = ID number per exportInterval = Cell column<br>Layer = Cell rowS_V_mean = Mean S_V in the cell (dB re 1m^-1)<br>NASC = Nautical area scattering coefficient (m²nmi^-2) for the cellS_V_max = Maximum Sv in the cell (dB re 1m^-1)<br>S_V_min = Minimum Sv in the cell (dB re 1m^-1)S_V_noise = Mean noise Sv in the cell (dB re 1m_-1)<br>Depth_mean = Mean depth of the cell (m)Ping_M = Ping number of middle ping in the cell<br>Dist_M = GPS-measured distance from first ping to middle ping in the cell (m)Date_M = Date of middle ping in the cell (YYYYMMDD)<br>Time_M = Time of middle ping in the cell (UTC)Lat_M = Latitude of middle ping in the cell (decimal degrees)<br>Lon_M = Longitude of middle ping in the cell (decimal degrees)Program_version = Echoview software version number<br>Processing_version = File format version used for analysis (value = 3 since Echoview 1.40)Processing_date = Date on which the data were exported (YYYYMMDD)<br>Processing_time = Time at which the data were exported (EST)Alpha = Absorption coefficient from calibration file (dB/m)<br>Gain_constant = Value of echosounder calibration constant (dB re 1m²/m³)Noise_Sv_1m = Background noise at 1m (dB re 1m²/m³)<br>ABC = Area backscattering coefficient for the cell (m²m^-2)Thickness_mean = Mean extent along the beam axis of cell (m)<br>Frequency = Echosounder frequency value (kHz)