fix_nbr

Last updated Fri Nov 19 12:57:27 1999


Fix NB ADCP raw files

1. USAGE

fix_nbr control_file

2. DESCRIPTION

This utility can be used to fix recorded values in NB ADCP raw files. Currently, only fixing of ship's attitude is implemented. See below for the syntax of the control file.

3. PARAMETERS

The control file must contain the following parameters:



year_base: YYYY

Year base to use for conversion of time into decimal days. Note that since the NB ADCP raw format does not contain year information, this parameter should be set to year of data collections.

file_list: file

Name of a file containing the successive names of NB ADCP raw files to fix. This file can contain C-syntax comments.

log_file: file

File name for recording log information about fixing process.

out_dir: directory

Path to directory where fixed raw files should be written.

4. OPTIONS

In addition to the parameters listed above, the following options are available:



OPTIONS:

This key word can be used to improve the clarity of the control file and specify the beginning of options. It has no effect.

use_scan_nav_output:

This method allows to fix NB ADCP raw files with processed navigation data resulting from scan_nav(1). The following sub-options are available:



file_name: file

Name of file containing fixes. The format of this file must be the same as the output of scan_nav(1).

heading

Must be specified if heading data have to be fixed.

pitch

Must be specified if pitch data have to be fixed.

roll

Must be specified if roll data have to be fixed.

time

Must be specified if time data have to be fixed.

end

This keyword is mandatory and terminates the list of selected sub-options.



transducer_misalignment:

This option can be used to correct NB ADCP raw files for misalignment of the transducer, in which case one or more of the following parameters must be specified:



heading= heading_offset



pitch= pitch_offset



roll= roll_offset



end

This keyword is mandatory and terminates the list of selected sub-options.

Values must be in degrees. The specified offset is subtracted from the measured value to yield the expected correct value. These offsets are set to 0.0 by default.

end

This keyword is mandatory and terminates the list of selected options.

If both method are selected, tilt corrections are performed on values from the external navigation file.

5. TIME RANGES

Finally, the control file is terminated by a list of time ranges. See time_rng(5) for the syntax of these.

6. OUTPUT FILES

Generated fixed NB ADCP raw files have exactly the same name as input ones, except that they are located in the specified output directory.

The log file contains information about fixing process, as well as reading status from the navigation file.

7. AUTHOR

Pierre Jaccard, Geophysical Institute, University of Bergen, 1999


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