pyhum.e1e2 module¶
Analysis of first (e1, ‘roughness’) and second (e2, ‘hardness’) echo returns from the high-frequency downward looking echosounder
Generates generalised acoustic parameters for the purposes of point classification of submerged substrates/vegetation
Accounts for the absorption of sound in water
Does a basic k-means cluster of e1 and e2 coefficients into specified number of ‘acoustic classes’
Based on code by Barb Fagetter (blueseas@oceanecology.ca)
Syntax¶
You call the function like this:
[] = PyHum.e1e2(humfile, sonpath, cs2cs_args, ph, temp, salinity, beam, transfreq, integ, numclusters, doplot)
Parameters¶
- humfile : str
- path to the .DAT file
- sonpath : str
- path where the *.SON files are
- cs2cs_args : int, optional [Default=”epsg:26949”]
- arguments to create coordinates in a projected coordinate system this argument gets given to pyproj to turn wgs84 (lat/lon) coordinates into any projection supported by the proj.4 libraries
- ph : float, optional [Default=7.0]
- water acidity in pH
- temp : float, optional [Default=10.0]
- water temperature in degrees Celsius
- salinity : float, optional [Default=0.0]
- salinity of water in parts per thousand
- beam : float, optional [Default=20.0]
- beam width in degrees
- transfreq : float, optional [Default=200.0]
- transducer frequency in kHz
- integ : int, optional [Default=5]
- number of pings over which to integrate
- numclusters : int, optional [Default=3]
- transducer frequency in kHz
- doplot : int, optional [Default=1]
- 1 = make plots, otherwise do not
Returns¶
- sonpath+base+’rough_and_hard’+str(p)+’.csv’ : csv file
- contains the following fields: ‘longitude’, ‘latitude’, ‘easting’, ‘northing’, ‘depth’, ‘roughness’, ‘hardness’, ‘average roughness’, ‘average hardness’,’k-mean label’ of the pth chunk ‘average’ implies average over ‘integ’ successive pings
The following are returned if doplot==1:
- sonpath+’e1e2_scan’+str(p).png : png image file
- png image file showing the downward echosounder echogram overlain with the locations of the start and end of the first and second echo region envelope
- sonpath+’e1e2_kmeans’+str(p).png: png image file
- png image file showing 1) (left) volume scattering coefficient 1 versus volume scattering coefficient 2, colour-coded by k-means acoustic class, and 2) (right) e1 versus e2, colour-coded by k-means acoustic class
- sonpath+’rgh_hard_kmeans’+str(p).png : png image file
- png image file showing scatter plot of easting versus northing colour-coded by k-means acoustic class
- sonpath+’map_rgh’+str(p).png : png image file
- png image file showing scatter plot of ‘roughness’ (e1) overlying an aerial image pulled from an ESRI image server
- sonpath+’map_hard’+str(p).png : png image file
- png image file showing scatter plot of ‘hardness’ (e2) overlying an aerial image pulled from an ESRI image server
- sonpath,’Rough’+str(p).png : png image file
- png image overlay associated with the kml file, sonpath,’Hard’+str(p).kml
- sonpath,’Rough’+str(p).kml : kml file
- kml overlay for showing roughness scatter plot (sonpath,’Rough’+str(p).png)
- sonpath,’Hard’+str(p).png : png image file
- png image overlay associated with the kml file, sonpath,’Hard’+str(p).kml
- sonpath,’Hard’+str(p).kml : kml file
- kml overlay for showing harness scatter plot (sonpath,’Hard’+str(p).png)
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