Statistics output

Along with the final results files, EddyPro creates at least one subfolder in the user-specified output folder:

..\eddypro_stats\: contains seven files of basic statistics calculated on all available sensitive variables, at 7 different levels of processing. These files have a static format that includes statistical data for all sensitive variables, except the analyzer’s cell in/out temperature. Statistics for variables that are not available are replaced by the string “n/a” (not available).

The seven levels of statistics refer to those calculated on the following datasets:

  1. Unprocessed (dataset as imported from the raw file)
  2. After despiking
  3. After crosswind correction
  4. After Angle of Attack correction
  5. After double rotation for tilt correction
  6. After time lag compensation
  7. After detrending

..\eddypro_user_stats\: contains seven files of basic statistics calculated on all available non-sensitive variables (including user-defined variables and sensitive variables not used for flux computation). These files have a dynamic format, including statistics only for available non-sensitive variables. This folder and the seven files contained in it are created only if EddyPro detects at least one non-sensitive variable.

Like the statistics calculated on sensitive variables, the seven levels of statistics refer to those calculated on the following datasets:

  1. Unprocessed (dataset as imported from the raw file)
  2. After despiking
  3. After crosswind correction
  4. After Angle of Attack correction
  5. After double rotation for tilt correction
  6. After time lag compensation
  7. After detrending

Note: Statistics on non-sensitive variables may result in seemingly wrong values (such as zero or not-a-number). This may happen when, for example, a variable has a constant value throughout the file, as with some instrument diagnostic variables. In these cases, however, high order statistics lose representativeness and usefulness.

Statistics files content

The statistics file is described below and in Table 3‑3.

File information

  • Raw file name
  • Date and time of the end of the averaging period
  • Number of valid records used for the current averaging period

Statistics

  • Mean values
  • Variances
  • Covariances of all variables with the three wind components
  • Standard deviations
  • Skewness
  • Kurtosis
Table 3‑3. The following table summarizes all output results available in the statistics files. In the table, var stands for any available sensitive or non-sensitive variable. The following table summarizes all output results available in the statistics files. In the table, var stands for any available sensitive or non-sensitive variable.
Label Description
filename Name of the raw file (or first file of a set) from which the data in the current averaging interval was extracted
date Date of the end of the averaging period
time Time of the end of the averaging period
n_samples Number of valid records found in the raw file (or set of raw files)
mean (var) Mean value of variable (var)
var (var) Variance of variable (var)
cov (u/var) Covariance between the u wind component and var
cov(v/var) Covariance between the v wind component and var
cov (w/var) Covariance between the w wind component and var
st_dev(var) standard deviation of variable var
skw(var) skewness of variable var
kur(var) kurtosis of variable var