This component provides a mechanism to apply the single-angle absorption correction for filter based measurements described in Bond et al. 1999. Data are left at their native wavelengths by applying a 0.97 factor to undo the implicit wavelength adjustment in the original correction.
Usage
da.corr.bond1999 [switches…] [[station] variables times [archive]|[file]]
Switches
- --coarse[=BOOLEANS]
-
When enabled, this sets the K1 values to a function of the scattering Ångström exponent suitable for coarse-mode aerosol.
Default: Disabled
- --correct=SELECTION
-
These are the variables to that the correction is applied to. This option is mutually exclusive with instrument specification.
Default: All absorptions
- --extinction=SELECTION
-
These are the variables to the light extinction coefficients used by the correction are contained in. By default none are used. This option is mutually exclusive with instrument specification.
- --extinction-instruments=SUFFIX…
-
These are the instrument suffixes that input light extinctions are read from. For example S11 would usually specifies the reference nephelometer. This option is mutually exclusive with manual variable specification.
- --instruments=SUFFIX…
-
These are the instrument suffixes to correct. For example S11 would usually specifies the reference nephelometer. This option is mutually exclusive with manual variable specification.
Default: All instrument suffixes
- --k1=INPUT
-
This is the fraction of (wavelength adjusted) scattering subtracted from the absorption values. This option is ignored when operating in coarse mode, where the fraction subtracted is a function of the Ångström exponent.
Default: 0.02
- --k2=INPUT
-
This is the factor that the resulting absorption (after scattering subtraction) is divided by to get the final result. When operating from extinction the K1 value is subtracted from this.
Default: 1.22
- --scattering=SELECTION
-
These are the variables to the light scattering coefficients used by the correction are contained in. This option is mutually exclusive with instrument specification.
Default: All scatterings from S11
- --scattering-instruments=SUFFIX…
-
These are the instrument suffixes that input light scatterings are read from. For example S11 would usually specifies the reference nephelometer. This option is mutually exclusive with manual variable specification.
Default: S11
- --smoothing=SMOOTHER
-
This is the smoothing applied to the scattering and/or extinction inputs before any calculation using them.
Default: 3-minute TC low pass filter
Arguments
If no bare word input specification is supplied then data are read from standard input.
- station
-
This argument is used to specify the station used to look up variables that do not include a station as part of an archive read specification. The station is the three letter GAW station code of the location, such as
BND
. The argument accepts multiple stations specified as regular expressions and separated by:
or;
or,
. For exampleBND,MLO
and(BND|MLO)
are two ways of selecting both the BND and MLO stations.The special value
allstations
may also be specified to select all stations. - variables
-
This argument may be split into multiple actual program arguments. Each part consists of one or more variable specifications separated by
,
(commas). The station and archive used if none are explicitly given are defined in the other arguments or inferred from system defaults. For example simplyBsB_S11
selects the blue scattering from the S11 instrument and returns all cut sizes and metadata. If instead::BsB_S11:pm10
is used then only PM10 scattering is returned. That is, the selection specifies "any" station and archive (the defaults are set in the other arguments) then requires that it has the "PM10" flavor. A specification such asbnd:BsB_S11,thd:BsB_S11
allows for data selection from multiple stations.This may also be used to select a "record" type alias such as "S11a". In this mode all the variables defined in the alias are returned.
Finally the special value
everything
can be used to select all available data for the given station(s) and archive(s). - times
-
This argument may be split into multiple actual program arguments. This full list of time arguments defines a time bounds list that sets the range of data queried. The final resulting data are clipped to the given time bounds but any values that intersect them are returned.
- archive
-
This argument is used to specify the archive used to look up variables that do not include an archive as part of an archive read specification. The archive is the internal name, such as
raw
orclean_meta
. The argument accepts multiple archives specified as regular expressions and separated by:
or;
or,
. For exampleraw(_meta)?
selects both theraw
andraw_meta
archives.The special value
allarchives
may also be used to select all available archives. - file
-
This argument is used to specify the the file to read data from. If it is present and exists then data is read from the given file name instead of from standard input. Alternatively
-
(a single dash) may be used to explicitly specify standard input.
Examples
- Defaults
-
This will correct all absorptions present using the scatterings from the S11 instrument. The default values for K1 (0.02) and K2 (1.22) will be used.
da.corr.bond1999 bnd S11a 2015-05-01 2015-05-03
Or:
da.corr.bond1999 input_file.c3d
Or:
da.get bnd S11a 2015-05-01 2015-05-03 | da.corr.bond1999
- Single instrument with manual constants
-
This will correct all absorptions from A11 using extinctions from E11. Non-standard constants with K1 = 0.03 and K2 = 1.23 are also used.
da.corr.bond1999 --extinction-instruments=E11 --instruments=A11 --k1=0.03 --k2=1.23 bnd S11a 2015-05-01 2015-05-03
- Single variable in coarse mode
-
This will correct only the variable BaG_A11 using the coarse mode constants.
da.corr.bond1999 --coarse --correct=bnd:raw:BaG_A11 bnd S11a 2015-05-01 2015-05-03