Kipp&Zonen LAS MkII ET system User Manual

Page 42

Instruction Manual - LAS MkII ET System

Receiver
Coordinates of LAS MkII receiver:

…........………………………………………………………………………………………………………………………………………………………………………………

[Latitude, o]

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

[Longitude, o]

…………………………………………………………………………………………………………………………………………………………………………………………............................................

[Height, m] (above ground)

…………………………………………………………………………………………………………………………………………………………………………………………………………………………...

[Elevation, m] (above sea level)

Signal strength on receiver display(UDEMOD):

………………………………………………………………………………………………………………………………………………………………….…………

[mV]

Path length set at receiver:

…………………………………………………………………………………………………………………………………………………………………………………………………………………………….

[m]

Mean vegetation height at receiver site:

……………………………………………………………………………………………………………………………………………………………………………………......……

[m]

Effective Height of LAS MkII Scintillometer
The accuracy of the fluxes of sensible heat and evapo-transpiration depends strongly upon the mean height of the LAS MkII
optical beam above the surface. In case the area is completely flat the average beam height can be easily derived from the
transmitter height and the receiver height.

In case the area is complex it becomes more difficult to determine the effective height of the beam. The EVATION software has
a special tool that helps the user to determine the effective height; the effective height calculator.

The calculator needs the following input data:
• The elevation of the transmitter site
• The installation height of the transmitter above the ground
• The elevation of the receiver site
• The installation height of the receiver above the ground
• The elevation and position of a number of points along the beam (a cross-section over the optical path)

By entering this information into the effective height calculator the software provides the effective height of the LAS MkII beam,
which will be used in the processing of data into fluxes.

Use a table, such as that below, to collect a number of cross-section points. In this case the ‘Reference’ point is ground level at
the transmitter site.

As the final step we recommend filling in an Installation Form for the System. The information in this form will be used to configure
the EVATION software.

General Information

Date:

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………...

[Year/Month/Day]

Installed by:

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….........

Station name:

………………………………………………………………………………………………………………………………..

(convenient to use in EVATION as the working directory)

Weather station sensors / data logger channel

Coordinates of weather station:

………………………………………………………………………………………………………………………………………………………………………........................

[Latitude, °]

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….....

[Longitude, °]

…………………………………………………………………………...…………………………………………………………………………...…………………………………………………………………………..

[Height, m] (above ground)

…………………………………………………………………………...…………………………………………………………………………...…………………………………………………………………

[Elevation, m] (above sea level)

Mean vegetation height at station site:

………………………………………………………………………………………………………………………………………………………………………...........................

[m]

LAS MkII Scintillometer
Scintillometer serial number:

………………………………………………………………………………………………………………………………………………………………………………………………………………………………..

Exact path length (according to GPS or map):

……………………………………………………………………………………………………………………………………………………………………………………

[m]

Transmitter
Coordinates of LAS MkII transmitter:

…………………………………………………………………………………………………………………………………………………………………………………

[Latitude, o]

[Longitude, o]

[Height, m] (above ground)

[Elevation, m] (above sea level)

Power adjustment setting:

……………………………………………………………………………………………………………………………………………………………………………………….......................................…

[-]

Mean vegetation height at transmitter site:

………………………………………………………………………………………………………………………………………………………………………………………..

[m]

Points in optical

path cross-section

Transmitter site, Tx (Reference)
Intermediate point 1
Intermediate point 2
Intermediate point 3
Intermediate point 4
Intermediate point 5
Intermediate point 6
Intermediate point 7
Intermediate point 8
Intermediate point 9
Receiver site, RX

0
0
3
7.5
7.5
20
20
18
18
25
36

0
500
750
1000
2300
3000
3500
3700
4000
4500
4700 (Path Length)

Elevation with respect to

reference site ground [± m]

Horizontal distance

from reference site [m]

Installation height of

LAS MkII with respect

to the site ground [m]