You will need several different programs, as well as software from the UH ADCP group.
We recommend you start by learning about CODAS processing with the python script “quick_adcp.py”, run on “pingdata” (averaged data from an RDI NB150) or LTA data (averaged data acquired by VmDAS). You must be on line or have qdemo_lta.zip installed.
You should start with this file
Specifically
Under “Practice Datasets” look for the column with LTA example.
- Get the data, read the links, process the data:
- Look at the example directory and notes for more information.
Short answer: ‘yes, but less time than it would take to write your own code’.
Longer answer:
That depends on many factors, including
how well you know your computer (the commandline interface, how to configure the paths and environment variables)
how well you know matlab (to explore the data directly)
your familiarity with the instrument (what is measured, what is stored in the data)
your familiarity with the processing steps (what should be done, how to recognize problems)
how good your dataset is (does it have clock problems? navigation problems?)
the manner in which the heading correction (to the gyro) will be calculated (pingdata with ue4 is easy, LTA is hard)
For a unix-savvy matlab-aware individual working with pingdata, it could be as little as a few days to gain some experience with the processing.
For person on a Windows machine who has never dealt with the C:\ command line, who does not know matlab, and who as never seen ADCP data before, it would be longer, potentially weeks not days.
For someone already familiar with CODAS processing steps, you can
- read a quick_adcp.py overview,
- look at a more detailed quick_adcp.py processing tutorial
- explore command-line help in quick_adcp.py itself (“quick_adcp.py - -help”).
Yes, the zipfile “doc.zip” from this location contains all the UH Currents group CODAS and UHDAS documentation. Follow these instructions to ensure that CODAS setup and processing documentation is accessible on your computer.
If you are about to leave, and you want to be able to run CODAS processing or look at data while off line, you might consider grabbing all the zip files listed, installing Python, and definitely making sure you have Matlab installed.
That depends on the instrument and data acquisition system used on your cruise. This link has instructions for most typical instrument+acquisition systems. In all cases, you are left with matlab files you can load and plot. Only in UHDAS is any plotting done for you.
This link gives a brief introduction to the data in a UHDAS cruise directory and points to useful tools for reading the data
You can use matlab to look at the data from the database or to look at the single-ping data. See this link for more information. Depending on the age of the UHDAS installation, you may need to install all of the Univ. Hawaii CODAS programs, or you may be able to start with just one matlab program.
Please read about CODAS conventions (eg. decimal day is zero-based)
Note
The database has undergone preliminar processing, but steps remain to ensure there are no calibration errors, gaps, or bad profiles.
A Black Box has already been run (automated CODAS processing). You now need to deal with the last parts of the processing manually.
If you have never processed a dataset with CODAS before, and if you want confidence that your final product is good, you should start by reading about quick_adcp.py and running through the LTA demo. The best place to start is the quick_adcp.py overview.
Once you have gone through the LTA demo and have some confidence with the tools, take a look at these documents...
- CODAS conventions
- cruise directory contents
- overview of UHDAS + CODAS at sea, specifically the Processing Component
... and then, to reprocess or finish processing the data from a cruise, look at the UHDAS Data Processing Demo and follow the instructions closest to your case.
Note
The UHDAS demo is contained in qdemo_uhdas.zip . You should install this on your computer, along with all the rest of the appropriate zip files. NEVER ALTER ANYTHING in the programs directory, but you can copy files and directories from q_demos/uhdas to practice the demo.
Yes, there has been a bug in the code wherein the blanking over the bottom due to side-lobe reflection was hardwired to expect beams with 30degrees. This has been updated in the Mercurial repositories as of May 1, 2009. If your code is older than that, you must update your CODAS installation. As of this writing, the new executables have not all been compiled yet. This is an excellent opportunity to install CODAS software using Mercurial repositories. See this link for instructions.
An ADCP with 30deg beams can only use 85% of the water column when the bottom is in range, but with 20deg beams the useful data range is more like 95% of the total.
It is not hard to reset the bottom-masking flags. Explanations and prescriptions are here