Kipp & Zonen LAS, Instruction Manual

Page: 10 / 75

9
This station comprises sensors, a mast with cross arms and cable guys, a data logger and a power
supply (battery and solar panel). In this way the user is able to place the meteorological station up to
5km away from the
LAS / XLAS receiver, preferably near the centre of the path of the LAS / XLAS or
at another representative spot. The RF telemetry link operates at 2.4 GHz, which is license free
globally
1
. Extra advantage: all data including the signals of the LAS / XLAS are stored centrally at the
meteorological tower on a 2Mb PCMCIA flash card.
The data processing of the
LAS-BET and LAS-RET systems is done by a software program, called
EVATION (stands for evapotranspiration). This user-friendly program, developed by Kipp & Zonen,
processes the data to (daily) fluxes of sensible and latent heat. In Figure 1 an overview is shown of the
LAS-RET system. Figure 2 shows the LAS-BET system (without the RF telemetry link).
LAS-Transmitter
LAS-Receiver
Datalogger (Master)
U
Cn2
and U
demod
LAS-system
Meteorological sensors:
Computer with PCMCIA card reader and EVATION
software
Net radiation
Soil heat flux
Temperature / humidity
Wind speed / direction
U
Cn2
,U
demod
and meteorol. data
(2 Mb Flash card or RS-232)
Figure 2: Schematic overview of the LAS-BET system. This system consists of a LAS / XLAS
scintillometer and a number of meteorological sensors. All sensors (including the LAS) are measured by
1 COMBILOG data logger. The data is stored on a 2 Mb flash card. Once the data of the Flash card has
been stored on a computer, the EVATION software processes the data to fluxes of sensible heat and
evaporation.
1
Optional license free bands are: 915 MHz (US & Canada) and 922 MHz (Australia & Israel)