EC Raw Binary Format (CH-FRU)

See here for more info about the EC raw binary format.


An overview of used abbreviations can be found here: Abbreviations

Setup since 2005


(1) Raw binary files before 2005070515.b11 contain erroneous data and must not be used.
(2) File extension was changed back to *.X* on 17 Nov 2017, 19:00.
(3) Separation settings estimated from photos and map: N+3.5 E-1 V-0.5
(4) SA orientation is most likely still 342°, although in this table 145° was given previously. With the 145° setting the wind direction is approx. 180° different from previous calculations and from Zeeman et al. (2010).
(5) Calibration gas: There was an issue with the calibration gas used to calibrate the IRGA75. As a consequence, the CO2 concentrations in the raw data files have to be multiplied by 0.974 before flux calculations. This can be directly done during the conversion of the raw data binary files to CSV files when using bico. For more info about this issue see here: Wrong Calibration Gas 2017. Affected time period: all IRGA72 CO2 concentrations between 2016113012.b47 and 2019112707.X00.
For this year, multiple months of CH4 measurements are available.
(7) Sonic height and orientation: GIN entry 28 Oct 2022: “Measured eddy covariance sensor separation with respect to sonic north, where sonic path is 0/0: Horizontal Vertical separation: 0 (+-5) mm, Eastward separation: – 175 (+-5) mm, Northward separation: 288 (+-5) mm, Sonic north: 0 °, Sonic center to north-rod distance: 110 mm”.
(8) Sonic height and orientation: Sonic height was taken from this locations.table file: CH-FRU_locations.table_20100616.txt. The same file gives the sonic orientation as 0°, however, when comparing wind directions from these years with later years (when we know the orientation) then 335° gives the most similar results.
(9) Sonic height and orientation: These years are not listed in the locations.table file from (8). However, the sonic height has most likely not changed (2.55m). A comparison of wind directions from these years with later years seems to confirm the orientation. The orientation is also similar to what can be expected, see GIN entries from 30 Mar 2016 and 7 Jun 2016.
(10) Sonic height and orientation: Sonic orientation was detected from comparison of yearly wind directions with later years (2021, 2022). Sonic height should be the same as before. See also (8) and (9).
(11) New sonic format: data from the sonic anemometer now includes StaA (status address) and StaD (status data). The format R350-B is described in the bico settings here and here.
(12) Erroneous eddy covariance data between 12 Jun and 11 Jul 2023 14:00: EC data from this time period must not be used. In June and July the sonic anemometer produced erroneous wind data, best seen in the clear offset period (in blue) for the unrotated wind component w, (see plot here). Luckily, we had parallel measurements from a test system in close proximity (metres) that can be used instead. The test system used a different, new logging script, see below.

Setup with rECord data logging, since 2023

Parallel measurements with the rECord logging script instead of the sonicread (PDF) script. EC raw data files are stored as CSV files instead of compressed binary.

Last Updated on 18 Feb 2024 22:01