as.echosounder: Coerce Data Into an echosounder Object

In oce: Analysis of Oceanographic Data

Coerce Data Into an echosounder Object

Description

Coerces a dataset into a echosounder dataset.

Usage

as.echosounder(
  time,
  depth,
  a,
  src = "",
  sourceLevel = 220,
  receiverSensitivity = -55.4,
  transmitPower = 0,
  pulseDuration = 400,
  beamwidthX = 6.5,
  beamwidthY = 6.5,
  frequency = 41800,
  correction = 0
)

Arguments

time	times of pings.
depth	depths of samples within pings.
a	matrix of echo amplitudes, as would be stored with read.echosounder().
src	optional string indicating data source.
sourceLevel	source level, in dB (uPa at 1m), denoted sl in reference 1 p15, where it is in units 0.1dB (uPa at 1m).
receiverSensitivity	receiver sensitivity of the main element, in dB(counts/uPa), denoted rs in reference 1 p15, where it is in units of 0.1dB(counts/uPa)
transmitPower	transmit power reduction factor, in dB, denoted tpow in reference 1 p10, where it is in units 0.1 dB.
pulseDuration	duration of transmitted pulse in us
beamwidthX	x-axis -3dB one-way beamwidth in deg, denoted bwx in reference 1 p16, where the unit is 0.2 deg
beamwidthY	y-axis -3dB one-way beamwidth in deg, denoted bwx in reference 1 p16, where the unit is 0.2 deg
frequency	transducer frequency in Hz, denoted fq in reference 1 p16
correction	user-defined calibration correction in dB, denoted corr in reference 1 p14, where the unit is 0.01dB.

Details

Creates an echosounder file. The defaults for e.g. transmitPower are taken from the echosounder dataset, and they are unlikely to make sense generally. The first three parameters must be supplied, and the dimension of a must align with the lengths of time and depths. The other parameters have defaults that are unlikely to be correct for arbitrary application, but they are not essential for basic plots, etc.

Those who use the readHAC package to read echosounder data should note that it stores the a matrix in a flipped and transposed format. See that package's demo code for a function named flip() that transforms the matrix as required by as.echosounder(). Indeed, users working with HAC data ought to study the whole of the readHAC documentation, to learn what data are stored, so that oceSetMetadata() and oceSetData() can be used as needed to flesh out the contents returned by as.echosounder().

Value

An echosounder object.

Author(s)

Dan Kelley

See Also

Other things related to echosounder data: [[,echosounder-method, [[<-,echosounder-method, echosounder, echosounder-class, findBottom(), plot,echosounder-method, read.echosounder(), subset,echosounder-method, summary,echosounder-method

oce documentation built on Sept. 11, 2024, 7:09 p.m.