Campbell Scientific CPEC200 Closed-Path Eddy-Covariance System - Manual (Page 79)

Appendix C. Output Variables
The next eleven values ( wind_speed through flux samples) give several values
associated with the online fluxes. The number of samples included in these
calculations ( flux_samples) includes only those samples for which all of the
data (sonic, irga, and pump) are OK.
The next twenty-two values ( Ts_stdev through Tc_Uz_cov) are the covariance
matrices of the various flux components.
The next nineteen values ( Ux_Avg through diag_CPEC_Avg) are averages of
the corresponding public variables. Many of these values are similar to lagged
values that are also found in this table, for example Ux_Lag_Avg and
Ux_Avg. These differ in two ways. First, the lagged versions represent an
average of a slightly different time period (up to two seconds earlier,
corresponding to the actual online flux calculations). Second, the lagged
versions are filtered to exclude values for which a diagnostic flag was set. The
non-lagged versions are simply the averages of all of the measurements within
the output interval. The rest of the values provide diagnostic information about
the CPEC200 system.
The value of the compile switches as shown in TABLE C-2 depends on the
constants as described in Section 5.4.2, Compile Switches. The code shown in
the table can be either V, S, or LWS, or a combination of two of the codes.
 V is defined if VALVE_MODULE = True
 S is defined if SCRUB_MODULE = True and
VALVE_MODULE = True
 LWS is defined if Leaf_Wetness_Sensor = True
TABLE C-2. Values stored in table flux
Compile
Switch Variable Name Units Description
TIMESTAMP TS Date and time the record was measured
RECORD RN Record number
Hs W∙m -2 Sensible heat flux from sonic temperature Ts
Hc W∙m -2 Sensible heat flux from corrected sonic temperature
Tc
LE W∙m -2 Latent heat flux
Fc mg∙m -2 ∙s -1 CO
2
flux
tau kg∙m -1 ∙s -2 Momentum flux
u_star m∙s -1 Friction velocity
Ux_Lag_Avg m∙s -1 Average of (lagged) U
x
Uy_Lag_Avg m∙s -1 Average of (lagged) U
y
Uz_Lag_Avg m∙s -1 Average of (lagged) U
z
Ts_Lag_Avg ºC Average of (lagged) T
s
sonic_samples Number of samples included in previous 5 averages
CO2_Lag_Avg µmol∙mol -1 Average of (lagged) CO
2
H2O_Lag_Avg mmol∙mol -1 Average of (lagged) H
2
O
cell_tmpr_Lag_Avg ºC Average of (lagged) cell temperature
cell_press_Lag_Avg kPa Average of (lagged) cell pressure
diff_press_Lag_Avg kPa Average of (lagged) differential pressure
irga_samples Number of samples included in previous 5 averages
pump_flow_Lag_Avg LPM Average of (lagged) pump flow
pump_OK_samples Number of samples included in previous average
C-3