Soil Moisture & Salinity Mapping

Polarimetric L-Band Microwave Radiometer

PLMR is a compact L-band imaging radiometer that generates push-broom images of scene brightness temperature in vertical and horizontal polarization. Customer-generated algorithms are used to extract ocean surface salinity and soil moisture from the measured brightness temperature data.

PLMR References

 

PLMR Features

• six parallel radiometer channels using ultra-stable radiometer module

• built-in radiometric calibration loads: warm(ambient) and cold(COLFET)

• constant temperature enclosure

• operates from various small aircraft

• turn-key operation

• RFI detection using dual -detector (kurtosis) method

 

PLMR Specifications
Operating frequency:  

1400 to 1426 MHz

 
Brigthness temperature: measurement range: 0 – 350K ; precision 0.7K with 1s dwell time
Antenna:  

microstrip patch (8 x 8 array ) with integrated microstrip feed

dual linear polarization (V & H)
Butler beamformer ; 6 beams at ±8°, ±21°, ±38° off broadside
beamwidth (3dB): 15°
Electrical Power: electronics:  0.7A @ 28VDC ; heating:  9A(max) @ 28VDC
Size: 37″ x 37″ x 7″ ( 94 cm x 94 cn x 20 cm )
Weight: 90 lb ( 40 kg )

PLMR installed on twin engine aircraft

This airborne surface salinity map was obtained during the 2000-2001 monsoon season using SLFMR (single polarization version of PLMR) showing freshwater plumes originating from the Johnstone and Russell/Mulgrave river basins, flowing into the Great Barrier Reef Lagoon. Color scale is in ppt. Image courtesy Flinders University (Australia).