Optical Microwave Scintillometer system

Optical Microwave Scintillometer system

An optical scintillometer, such as the Kipp & Zonen LAS MkII or X-LAS MkII can be easily combined with a microwave scintillometer to provide direct measurements of both sensible heat flux and latent heat flux (evapotranspiration) averaged over a large area. The long path length range and scale of turbulent scintillations measured with the X-LAS MkII, match very well with that of a microwave scintillometer.

The transmitter projects a beam of 160 GHz radiation and the receiver has an aperture of 300 mm diameter. Both operate from 12 VDC (an AC supply is optional). In combination with an optical Large Aperture Scintillometer, and an all-in-one weather station, this allows simultaneous path averaged measurements of latent and sensible heat flux within the atmospheric surface layer, on scales comparable to satellite measurements or atmospheric models.

The microwave scintillometer comes with a comprehensive operating software package and in-built computer. The LAS MkII receiver plugs directly into the microwave scintillometer receiver, which collects analogue data from, and supplies power to the LAS. The transmitters are co-located at the end of the measurement path. The software synchronously digitizes the microwave and optical raw signals. Complete data processing from raw signals to heat fluxes is performed in real time. All data products are automatically stored and can be continuously visualized when a suitable display is connected.

The advantages of the system are:

• Rapid, direct measurements of the sensible heat and latent heat fluxes, plus the structure parameter Cn2 of the turbulent surface layer, all averaged over a source region, so no time averaging is needed and it is representative of a large area.
• No influence of the mounting structure on the measurements.
• Remote sensing technique allowing measurements over open water, swamps, or sensitive natural habitats without disturbance.
• Easy installation and self-contained system, only requiring power.
• Very little maintenance and no moving parts for enhanced reliability.

Please contact us through [email protected] for more information on this system.

Antenna gain 52 dB

Beam width 0.45° FWHM

Gain stability > 2.0 × 10-5

Temperature stability < 0.03 K (two-stage control)

Output data:

Level 0

• 1 kHz digital raw data for microwave scintillometer and LAS
• housekeeping data.

Level 1

• (co)variances of the combined OMS system.

Level 2

• structure parameters ??², sensible and latent heat fluxes ?, ???