Configuration

FREQCOR is configured using .ini files (read with Python configparser). A configuration file defines:

• where to find input files (binned (co)spectra, EddyPro full_output, optional QC files),

• which processing mode to run (cospectra vs spectra, gas selection, plotting options),

• thresholds used for data selection and quality screening,

• where to write outputs.

An example configuration is provided in:

examples/metadata/FREQCOR_config_example.ini

File structure

The INI file is organized into sections:

• [IO]: input/output locations and read routine.

• [TIME_WINDOW]: optional time window filtering.

• [PROCEDURE_OPTIONS]: main algorithm switches (mode, gas, fitting, plotting, LUT classes).

• [EC_SETUP]: site metadata and sensor separation (spectral mode only).

• [USER_LIMITS]: thresholds for filtering and transfer-function checks.

• [PROCESSED_DATA]: optional caching of intermediate read outputs.

[IO]

Purpose: select the reader and point to all required input files.

• read_routine

  • FREQCOR_Read_EP: standard workflow using EddyPro binned cospectra exports.

  • FREQCOR_Read_TOF: alternative workflow for GEddySoft/TOF-type datasets.

• input_path

  • Folder containing the EddyPro full_output file.

• input_path_sp

  • Folder containing the binned (co)spectra (used by some workflows).

• binned_cosp

  • Substring used to identify binned cospectra files/folders.

• flx_meteo

  • Base name of the EddyPro flux/meteo/QC file (typically full_output).

• vitale_path

  • Folder containing the ICOS-ETC global flux flag file (Vitale et al., 2020), used only when vitale_qc_flags = 1.

• massman_path

  • Optional Massman coefficient file (used for plotting reference cospectra).

• output_path, output_file

  • Output directory and base name for the corrected flux output file.

[TIME_WINDOW]

Purpose: restrict computations to a time period.

• enable_time_window

  • 0: process all available data.

  • 1: process only the window defined by start_datetime and end_datetime.

• start_datetime, end_datetime

  • Format: YYYY-MM-DD HH:MM.

• enable_exclusion_windows

  • 0: no exclusion.

  • 1: exclude sub-periods defined by date_exclusion_start and date_exclusion_end.

• date_exclusion_start, date_exclusion_end

  • Comma-separated list of datetimes (same format as above). The number of start and end entries must match.

[PROCEDURE_OPTIONS]

Purpose: select the processing mode, gas, sorting strategy, fitting options, and plotting.

• sps

  • 1: cospectral approach.

  • 2: spectral approach (enables sensor-separation corrections).

• gss

  • Gas selector:

    • 1: CO2

    • 2: H2O

    • 3: O3

    • 4: CH4

    • 5: N2O

• LUT classing parameters

  • classnumwd / classnumrh: number of bins for the first sorting variable.

    • for H2O (gss = 2) the first sorting variable is RH;

    • otherwise it is wind direction (WD).

  • classnumcofws: number of wind-speed classes for cut-off frequency LUTs.

  • classnumcf_u, classnumcf_s: number of wind-speed classes for correction-factor LUTs (unstable and stable conditions).

• Spectral-mode (sensor separation) only

  • eq: Horst & Lenschow equation selector (e.g. 13 or 16).

• Transfer-function options

  • tf_sonic: apply theoretical correction to sonic cospectra (0/1).

  • tf_peltola: enable Peltola et al. (2021) fit form where applicable (0/1) (affects the Lorentz fit form only; Gaussian TF is unchanged).

• Plotting options (0/1)

  • plot_hh: individual half-hour plots (very verbose).

  • plot_main: main summary plots.

  • plot_aux: additional diagnostic plots.

  • plot_save: save figures to output_path instead of interactive display.

• Vitale QC integration

  • vitale_qc_flags

    • 0: use internal VM/F quality thresholds.

    • 1: use ICOS-ETC global flux flags (Vitale et al., 2020) from vitale_path.

[EC_SETUP]

Purpose: site metadata and sensor separation geometry.

• jsite

  • Site identifier (e.g. ICOS-style BE-Lon).

The following are used only when sps = 2 (spectral approach):

• zmeas: measurement height (m)

• disph: displacement height (m)

• rsz: vertical sensor separation (m)

• rseast: eastward sensor separation (m)

• rsnorth: northward sensor separation (m)

[USER_LIMITS]

Purpose: numerical thresholds controlling selection and TF checks.

• Wind-sector exclusion

  • wdmin, wdmax: range (deg from North) to discard.

• Flux thresholds for LUT construction

  • hlim, fclim, lelim: absolute-value thresholds for selecting (co)spectra used for cut-off frequency estimation.

  • hlcfu: sensible-heat threshold for selecting cospectra used for CF (unstable).

  • hlcfs: sensible-heat threshold for selecting cospectra used for CF (stable).

• Quality-flag thresholds

  • fvm: Vickers & Mahrt (1997) threshold (discard if VM flag > fvm).

  • ff: Mauder & Foken (2004) threshold (discard if F flag > ff).

• Transfer-function quality check and fitting ranges (Hz)

  • jtmin, jtmax: frequency range used for TF quality checks.

  • varclim: coefficient of variation limit for the TF quality check window.

  • tfmin, tfmax: frequency range used for TF fitting.

[PROCESSED_DATA]

Purpose: optional saving/loading of intermediate read outputs.

• enable_saving: save intermediate read outputs (0/1).

• use_timestamp: include timestamp in filenames (0/1).

• enable_loading: load previously saved outputs to speed up reading (0/1).

• file_prefix: prefix for saved files.

Validation

At runtime, FREQCOR validates the configuration to catch common issues early (e.g. invalid enumerations, inconsistent ranges, output path creation, and time window parsing).