3.1.5. Tools to access ADCP data

Note

A scientist with an existing UHDAS dataset who wants to use Matlab to access the ADCP data should look here

The following mechanisms exist for directly accessing data (into a program)

• The CODAS database can only be accessed with Python (direct read) or executables (read and write to disk). Matlab access to the data means reading *.mat files or netCDF files.

• Binary raw ADCP data can be accessed by both Matlab and Python.

Useful data products are scattered througout the UHDAS cruise directory, in the individual sonar processing directories, eg. vg0810/proc/os75nb in these locations:

data	files to use
every bin and every profile (matlab)	contour/allbins_*.mat
coarse resolution averaged ocean velocity	vector/vect*.mat
moderate resolution averaged ocean velocity	contour/cont*.mat
every bin and every profile (netCDF)	contour/*.nc
every bin and every profile (CODAS database)	adcpdb/a*.blk
figures from the cruise	png_archive/*.png

data source	what you get	python program	matlab program	C-code executable or Python script (extract to disk)
UHDAS *.raw	beam coords singleping, no navigation	Multiread	read.m	NA
UHDAS *.raw	earth coords singleping with navigation, with heading	NA	get_xfraw.m	NA
VmDAS *.ENR	beam coords singleping no navigation, no heading	Multiread	read.m	NA
VmDAS *.ENS	beam coords singleping with navigation, no heading	Multiread	read.m	NA
VmDAS *.ENX	earth coords singleping with navigation, with heading	Multiread	read.m	NA
VmDAS *.STA, *.LTA	earth coords averaged	Multiread	read.m	NA
CODAS database	matlab files earth coordinates: (further averaged) time, lon, lat ocean velocities	NA	NA	adcpsect (extract files to disk) contour_xy.mat, contour_uv.mat file description
CODAS database	matlab files earth coordinates: time, lon, lat ocean velocities (CODAS avg, eg 5min)	get_profiles	download load_getmat.m here (load the files created by getmat)	getmat (extract to disk) allbins*.m read with load_getmat.m
CODAS database	netCDF file earth coordinates: time, lon, lat ocean velocities (CODAS avg, eg 5min)	get_profiles		adcp_nc.py (extract netCDF file to disk) file description

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Although we are not actively using or devloping Matlab programs, we will ensure that the programs for reading CODAS Matlab output and raw RDI data files continue to work.

Most popular:

• Matlab access to data CODAS database:

  • matlab files (use load_getmat.m to load allbins_*.mat) from the CODAS processing directory. (see file description)

  • netCDF file (load the netCDF file into matlab)

Other useful tools:

• Python:

  • CODAS database: (every bin, every profile - eg. 5min averages) – read data with get_profiles)

  • read raw ADCP data (ENR, *.raw) with Multiread

  • extract netCDF file with adcp_nc.py

• Matlab:

  • read raw data (*.raw, or VmDAS output *.LTA, *.STA, *.ENR)

• extract matlab files from CODAS database:

• getmat (all bins and all profiles from a CODAS database, eg 5-min averages)

• adcpsect (getting time, velocities, and positions from a codas database, typically with further averaging, eg. 15min or 1hour). See adcpsect file description.

• HOWTO extract netCDF file:

• extract using command-line tool adcp_nc.py (see netCDF file contents).