bottom.hac {echogram}

Read detected bottom range from an HAC file

Description

This function imports, for a given acoustic channel, the detected bottom range stored in the ping tuple of an HAC file.

Usage

bottom.hac(hac, channel = NULL, plot = FALSE, maxDepth = NULL)

Arguments

hac

name of an HAC file.

channel

acoustic channel number.

plot

logical. if TRUE a plot is produced.

maxDepth

maximum depth (in m) represented in the plot.

Details

The acoustic channel is an integer, normally between 1 and n, where n is the number of frequencies used during data acquisition. When channel = 1, data from the lowest acoustic frequency is imported, while channel = n refers to the highest frequency present in the HAC file. By default, the function finds out the smallest channel number, because in some HAC files channel = 0. When a graphical representation is desired (plot = TRUE), the maximum displayed in the echogram depth can be provided as a negative integer with argument maxDepth.

Value

A data frame with two variables where every row represents one emitted ping:

pingTime

time of emitted ping.

detBottom

detected depth range in m.

Author(s)

Héctor Villalobos

Examples

hacfile <- system.file("hac", "D20150510-T202221.hac", package="echogram")
bottom.hac( hacfile )
bottom.hac( hacfile, plot = TRUE )