7.7.5. calib_new_instrument.txtΒΆ

The big overview is in
    codas_docs
    UHDAS Technical Documentation
    ADCP Data Quality: Calibration
    	 - Bottom Track Calibration of a new installation


Summary

(1) (re)install the instrument, with all attempts to put
    "beam 3" at 45deg to starboard.  It is not critical
    that the angle be exact; ultimately it is critical to
    determine the angle accurately, and it is much easier if
    we start with a god nominal guess.

(2) If this is a new instrument,  the ship configuration needs
    to have this new instrument added to its configuration.
    Eg.  Revelle swapped an NB150 for an OS150.  This requires
    a configuration change in the code.  As part of the change,
    the ADCP guru will regenerate "config" and "www".

(3) Run a test cruise at the dock (with the instrument wet)
    and verify that the UHDAS Gui tool behaves as expected,
    and the pictures come up after 5min (for the profile)
    and 20min (for the vector plot (the map)

(4) Before leaving port, start the cruise (suppose it was ZZ1405)
    but name it ZZZ1405_calib, because we are going to change
    a calibration number and need to start a new cruise for it to
    take effect.  We might as well identify the first segment
    with a reasonable name

    - turn on Bottom Track for the instrument we are calibrating
    - if this instrument is an Ocean Surveyor, use either
      broadband or narrowband, but not both

Once the ship is in water deeper than the range of the
new instrument, turn off bottom track:
  - stop logging
  - toggle bottom track off
  - start logging

(5) Suppose the new instrument is OS150 and we are running
    Bottom Track and Narrowband.  The calibrations are written to
    /home/data/ZZZ1405_calib/proc/os150nb/cal/botmtrk/btcaluv.out
    i.e.
    /home/data/CCCCCCCCCCC/proc/PPPPPPPPPPPPP/cal/botmtrk/btcaluv.out
               cruise name     processing dir

The file is updated every 15min, and eventually numbers will start
showing up in this file.  Look for the line near the bottom that
begins with the word "phase".  The value we need to know is the
median (or mean) phase.  We want over 5-10 "edited" bottom track
points, so several hours, if possible.

Suppose the last block looks like this


unedited: 130 points
edited:   117 points, 2.0 min speed, 2.5 max dev
            median     mean      std
amplitude   1.0038   1.0037   0.0032
phase      -5.3184  -5.2997   0.2687


We will "apply the bottom track calibration phase of -5.3".
This means we will change the transducer angle by SUBTRACTING
the value we just identified (also see below)

     new transducer angle = old transducer angle - (value from bottom track)
     new transducer angle = old transducer angle - (-5.3)
     new transducer angle = old transducer angle +5.3

(6) Before we edit the code,
    - stop logging
    - end cruise
    - kill UHDAS Gui

(7) Save the original file /home/adcp/config/proc_cfg.py to a
    backup name, eg: proc_cfg.py.orig
    Open /home/adcp/config/proc_cfg.py in an editor.
    Identify the lines that assign the values for "h_align"

    eg.


#----- begin python code snippet ------

# heading alignment:  nominal - (cal/watertrack)
h_align = dict(
    os150 = 45.0,
    os75  = 48.2,
)

#----- end python code snippet ------


==> We will replace the number 45.0 (the nominal value for OS150)
    with (nominal - bottomtrack), i.e.
          45      -   (-5.3)
    i.e.  48.3

The new code block looks like this (note the added comment)


#----- begin python code snippet ------

# heading alignment:  nominal - (cal/watertrack)
h_align = dict(
    os150 = 48.2,       # 45 - (-5.3)  from BT cal Oct 2014
    os75  = 48.2,
)

#----- end python code snippet ------

Save and exit.


(8) IF the instrument is an Ocean Surveyor, MAKE SURE the EA value in
/home/adcp/config/sensor_cfg.py is within about 5-10 degrees of
the h_align value above.  This line would be fine:

          'commands'    :  ('EA04500',),

(This is irrelevant for Workhorse or Broadband instruments)


(9)  Start the new cruise leg

     - Open UHDAS Gui tool
     - start cruise ZZZ1405
     - start logging

Troubleshooting:
- If the UHDAS Gui does not start or the buttons do not work,
  you made a typo.  Look at these files to determine what the
  error might be (look at the last files in /home/adcp/log
  with the suffix ".warn" or ".err")
- You should see the profile plot (5-minute plot) in less than 10min
  You should see the contour and vector plots (map) in about 20min


And of course, send email if there is a problem

uhdas@hawaii.edu




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2015/05/01