oce (version 0.9-20)

echosounder-class: Class to Store Echosounder Data

Description

Class to store echosounder data.

Methods

Accessing values. Data may be accessed as e.g. echosounder[["time"]], echosounder[["depth"]], echosounder[["a"]], etc. Items in metadata must be specifield by full name, but those in data may be abbreviated, so long as the abbreviation is unique. In addition to the actual data, some derived fields are also available: echosounder[["distance"]] calls geodDist to compute calculate distance along the ship track, echosounder[["Sv"]] returns a matrix of backscatter strength in DB, and echosounder[["TS"]] returns a matrix of target strength in dB. Assigning values. Everything that may be accessed may also be assigned, e.g. echosounder[["time"]] <- 3600 + echosounder[["time"]] adds an hour to time.

Details

The data slot is a list containing

• An infrequently updated record of the intrument position, in timeSlow, longitudeSlow and latitudeSlow. These are used in plotting maps with plot,echosounder-method.

An interpolated record of the instrument position, in time, longitude, and latitude. Linear interpolation is used to infer the longitude and latitude from the variables listed above.

depth, vector of depths of echo samples (measured positive downwards in the water column). This is calculated from the inter-sample time interval and the sound speed provided as the soundSpeed argument to read.echosounder, so altering the value of the latter will alter the echosounder plots provided by plot,echosounder-method.

The echosounder signal amplitude a, a matrix whose number of rows matches the length of time, etc., and number of columns equal to the length of depth. Thus, for example, a[100,] represents the depth-dependent amplitude at the time of the 100th ping.

A matrix named b exists for dual-beam and split-beam cases. For dual-beam data, this is the wide-beam data, whereas a is the narrow-beam data. For split-beam data, this is the x-angle data.

A matrix named c exists for split-beam data, containing the y-angle data.

In addition to these matrices, ad-hoc calculated matrices named Sv and TS may be accessed as explained in the next section.

See Also

Other classes provided by oce: adp-class, adv-class, argo-class, bremen-class, cm-class, coastline-class, ctd-class, lisst-class, lobo-class, met-class, oce-class, odf-class, rsk-class, sealevel-class, section-class, topo-class, windrose-class

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