Output Files

EC-PeT generates several types of output files that provide comprehensive information about the processed data, quality control results, and computed fluxes. All output files follow standardized formats for easy integration with other analysis tools.

Preprocessor Test Results

The preprocessor test output results are written into one file. Each line corresponds to one record. Apart from the headers, each line in this file corresponds to the same line in the interval and EC-PACK flux data file.

File Structure

Each line contains:

1. Time information: Start and end time of the record in three consecutive integer values: day of year, hour and minute (identical to the interval file)

2. Quality control flags: For each test and each variable, grouped by the tests

3. Quality measures: Calculated during the tests for each variable, grouped by the individual measures

The first line contains a space-separated list of column titles. Flag titles are constructed as variable-ID, underscore, test-ID.

Variable IDs

The variable IDs used in output files are:

Variable ID	Description
ux_	U-component of wind velocity
uy_	V-component of wind velocity
uz_	W-component of wind velocity
co2	CO₂ concentration
h2o	H₂O concentration
ts_	Sonic temperature
prs	Pressure

Quality Measures

The quality measures output include:

Code	Description
qmnan	Fraction of values removed due to error flags raised by the sensor (produced by instrument-flags check)
qmspk	Fraction of values removed as spikes by standard deviation despiking (produced by spk)
qmebi	Maximum fraction of empty bins of the value distribution (produced by res)
qmcon	Maximum number of consecutive values falling into the same bins (produced by drp)
qmskw	Skewness of the values in the record (produced by mom)
qmkrt	Kurtosis of the values in the record (produced by mom)
qmtrs	Maximum Haar transform value in the record (produced by dis)
qmvrn	Maximum coherent variance change value (produced by dis)
qmred	Minimum reduction of mean wind vector amount compared to mean wind speed (produced by nst)
qmrnu	Along-wind relative nonstationarity (relative increase of the mean wind over the record, approximated by a linear fit, produced by nst)
qmrnv	Cross-wind relative nonstationarity (relative increase of the mean wind over the record, approximated by a linear fit, produced by nst)
qmrns	Vector wind relative nonstationarity (relative increase of the mean wind over the record, approximated by a linear fit, produced by nst)
qmlag	Response ratio (correlation at zero shift normalized by maximum correlation, produced by lag)
qmcsp	Fraction of values removed as spikes by change rate despiking (produced by chr)
qmrat	Maximum value-to-value change rate in record (produced by chr)
qmmsp	Fraction of values removed as spikes by MAD despiking (produced by mad)
qmfwd	Difference between averaged subrecord covariance and record covariance (produced by fws)
qmtrd	Difference between covariances with and without linear detrending (produced by cot)
qmbdv	Kurtosis deviation from Gaussian distribution (produced by bet)
qmbpp, qmbpq	Parameters p and q of estimated probability density function (produced by bet)
qmbpi, qmbpx	Minimum and maximum values of variable in record (produced by bet)
qmvst	Maximum coherent variance change value (produced by vst)
qmftu	Turbulent fraction (produced by ftu)
qmsrv	Fraction of values not removed as spikes or due to instrument flags (produced by srv)

Example Output

doy1 h1 m1 doy2 h2 m2 ux__spk uy__spk uz__spk ... ux__qmspk uy__qmspk ...
180 12 00 180 12 30  0 0 0 ...  0.1944E-03  0.000      ...
180 12 30 180 13 00  0 0 0 ...  0.2222E-03  0.5556E-04 ...
180 13 00 180 13 30  2 2 2 ...         NaN         NaN ...

Postprocessor Test Results

The format is the same as for the preprocessor test results, except that test results are not grouped by individual variables but by fluxes. Quality measures are only calculated for tests that apply to all fluxes.

File Structure

Each line contains:

1. Time information: Start and end time in three integer values (day of year, hour, minute)

2. Quality control flags:

   For each test and each flux, grouped by tests

3. Quality measures: Calculated during the tests

Note

Except for the excessive error test, flags are identical for all fluxes.

Flux IDs

The flux IDs used are:

Flux ID	Description
tau	Momentum flux
h_0	Sensible heat flux
e_0	Latent heat flux
fc2	CO₂ flux

Quality Measures

Code	Description
qmmnw	Maximum amount of vertical wind after wind field correction (produced by mnw)
qmitt	Difference between calculated and measured ITC of temperature (produced by itc)
qmitw	Difference between calculated and measured ITC of vertical wind (produced by itc)
qmfkf	Fraction of footprint in the area of interest (produced by fkm)
qmfkx	Distance of the point of maximum footprint PDF (produced by fkm)

Example Output

doy1 h1 m1 doy2 h2 m2 tau_mnw h_0_mnw e_0_mnw ... qmmnw qmitt ...
180 12 00 180 12 30  0 0 0 ...  0.1943E-16   0.000       ...
180 12 30 180 13 00  2 2 2 ...  0.7595E-16  0.8496      ...

Quality-Checked Fluxes

The main output file contains quality-controlled flux data. Each line corresponds to one record, and the format is similar to the EC-PACK flux data file.

File Structure

The first six columns give the start and end time of each record. Quantities copied from EC-PACK output carry the same names. Each column giving a quantity is followed by a column giving its uncertainty (denoted by prefixing the name with “d”). Some quantities are output once in the unit used by EC-PACK and once in a unit more common in literature.

Standard Output Variables

Variable	Unit	Description
DOY Hr Mn		Start time (day of year, hour, minute)
DOY Hr Mn		End time (day of year, hour, minute)
UStar_qc	m/s	Friction velocity (quality controlled)
dUStar_qc	m/s	Uncertainty in friction velocity
UStar_flag	index	Quality flag for friction velocity
H_qc	W/m²	Sensible heat flux (quality controlled)
dH_qc	W/m²	Uncertainty in sensible heat flux
H_flag	index	Quality flag for sensible heat flux
LvE_qc	W/m²	Latent heat flux (quality controlled)
dLvE_qc	W/m²	Uncertainty in latent heat flux
LvE_flag	index	Quality flag for latent heat flux
FCO2_qc	kg/m²/s	CO₂ flux in mass units (quality controlled)
dFCO2	kg/m²/s	Uncertainty in CO₂ flux (mass units)
FCO2_flag	index	Quality flag for CO₂ flux
FmolCO2_qc	μmol/m²/s	CO₂ flux in molar units (quality controlled)
dFmolCO2	μmol/m²/s	Uncertainty in CO₂ flux (molar units)
Dir	deg	Mean wind direction (0-360° from north)
Mean(vectorU)	m/s	Mean horizontal wind speed (vector average)
Thetason	K	Mean sonic temperature
Mean(q)	kg/kg	Mean specific humidity
CO2Mixr	μmol/mol	Mean CO₂ mixing ratio
dCO2Mixr	μmol/mol	Uncertainty in CO₂ mixing ratio
rho	kg/m³	Mean air density
LStar	m	Obukhov length scale
FPTarget	percent	Footprint fraction within target area
pres	hPa	Mean atmospheric pressure

Example Output

DOY Hr Mn DOY Hr Mn     UStar_qc        dUStar_qc       ...
-   -  -  -   -  -      [m/s]           [m/s]           ...
180 12  0 180 12 30     0.64861         0.29180E-01     ...
180 12 30 180 13  0     0.45555         0.33961E-01     ...

Additional Output Files

Interval File

Contains time interval information for each averaging period. Format:

180 12  0 180 12 30
180 12 30 180 13  0
180 13  0 180 13 30

Log Files

Processing logs contain detailed information about:

• Processing progress and timing

• Error messages and warnings

• Configuration settings used

• Data statistics and summaries

• Quality control results summary

File Naming Conventions

EC-PeT uses standardized file naming conventions:

• flags1.dat: Preprocessor quality control

• planang.dat: Planar-fit tilt angles

• ec-flux.dat: Main flux file

• flags2.dat: Postprocessor quality control

• qc-flux.dat: Quality-controlled flux file