readHAC-package: Read acoustic HAC raw data

In readHAC: Read Acoustic HAC Format

Description

The HAC data format is a binary format containing so-called tuples. A tuple can hold various sorts of information depending on the tuple type. For instance tuples exist to specify positions, echosounder information and acoustic signal data etc. This R package can read, write and subset the HAC data format.

Details

See the description of the ICES HAC standard data exchange format, version 1.60.

References

McQuinn, Ian H., et al. Description of the ICES HAC standard data exchange format, version 1.60. Conseil international pour l'exploration de la mer, 2005. http://biblio.uqar.ca/archives/30005500.pdf

Examples

require(readHAC)

######################################################################
## Example file
hacfile <- system.file("hac", "Hac-test_000001.hac", package="readHAC")

######################################################################
## Step 1. Read hac data into R
hac <- readHAC(hacfile)
print(hac)

######################################################################
## Step 2. Select sub-components
pingdata <- ( subset(hac, softwarechannel==3 & type==10000) )
channel  <- ( subset(hac, softwarechannel==3 & type==9001 ) )
echosounder <- ( subset(hac, echosounder==channel$echosounder & type==901) )

######################################################################
## Step 3. Parse the binary data
print( parseHAC(pingdata) )
info <- parseHAC(channel)[5:7]
s <- ( parseHAC(pingdata)$"Sample value" )
s[s>0] <- NA  ## discard positive dB values
sec <- parseHAC(pingdata)$"Time CPU ANSI"; sec <- sec - min(sec)
flip <- function(x) t( x[nrow(x):1, ] )
image(sec, 1:nrow(s), flip(s), axes=FALSE, ylab="sample")
axis(1)
at <- seq(nrow(s), 1, by=-100)
axis(2, at=at, labels=nrow(s)-at)
box()
legend("topright", legend=paste(names(info), unlist(info)) )

Example output

Object of class 'HAC' containing 1346 tuples 
============================================ 

Tuple types:
                                     tuple  type count
1                          Position tuple     20   189
2               Generic Echosounder tuple    901    11
3                   Generic Channel tuple   9001    11
4                         Ping tuple U-32  10000   714
5               Ping tuple U-32-16-angles  10001   357
6 Split-beam detected single-target tuple  10090    63
7                     HAC Signature tuple  65535     1

Identifiers (to select tuples):
$type             	[ 20, 901, 9001, 10000, 10001, 10090, 65535 ]
$softwarechannel  	[ 0 - 10 ]
$echosounder      	[ 1 - 14 ]
$subchannel       	[ 9, 10 ]
$depthsensor      	[  ]
$distancesensor   	[  ]
$attitudesensor   	[  ]
$time             	[ 1075308210 - 1075308329 ]
$timefraction     	[ 140 - 9980 ]
$typeofdata       	[ 0, 1, 2, 3 ]
$pointer          	[ 2 - 1173809 ]
$length           	[ 6, 9, 14, 17, 20, 23, 36, 39, 44, 1094 ]
Tuple size [byte]                   [length=119] 4366 4366 ... 4366 4366
Tuple type []                       [length=119] 10000 10000 ... 10000 10000
Time fraction [s]                   [length=119] 0.938 0.938 ... 0.938 0.938
Time CPU ANSI C Standard time [s]   [length=119] 1075308211 1075308212 ... 1075308328 1075308329
Software channel identifier []      [length=119] 3 3 ... 3 3
Transceiver mode []                 [length=119] eavesdropping: the transceiver is receiving while another transceiver is transmitting eavesdropping: the transceiver is receiving while another transceiver is transmitting ... eavesdropping: the transceiver is receiving while another transceiver is transmitting eavesdropping: the transceiver is receiving while another transceiver is transmitting
Ping number []                      [length=119] 2520 2521 ... 2637 2638
Detected bottom range [m]           [length=119] 61.793 61.786 ... 61.864 61.689
Sample sequence number []           [dim=542x119] 0 0 ... 0 0 
                                                  ...
                                                  541 541 ... 541 541
Sample value (> threshold) [dB]     [dim=542x119] 18.040415 18.040415 ... 18.040415 18.040415 
                                                  ...
                                                  -82.761616 -84.748885 ... -82.432365 -85.60729
Tuple attribute []                  [length=119] original original ... original original
Backlink [byte]                     [length=119] 4376 4376 ... 4376 4376

readHAC documentation built on May 2, 2019, 10:14 a.m.