The Copernicus radar
The UFAM 35-GHz radar is a fully coherent Ka band instrument with a 2.4m dish. Pulse coding is used to provide enhanced sensitivity (a 10-bit code yields an extra 10dB over an uncoded pulse), allowing the detection of low reflectivity liquid water clouds and thin cirrus cloud. In addition, approximately 3 dB of sensitivity is gained by coherently integrating each pulse pair.
Importantly, the radar also transmits uncoded pulses: the coded and uncoded pulses are interleaved on a pulse-to-pulse basis, effectively allowing simultaneous measurement with and without pulse compression, enabling direct comparisons between coded and uncoded data. This allows erroneous features introduced by the coding to be identified, such as range side-lobes, which can be a problem in regions with a high reflectivity gradient.
Frequency: 34.960 GHz
Transmit power: 1.5 kW peak pulse
Antenna: 2.4 m parabolic dish
Pulse compression: 10-bit complementary binary phase coding
Pulse width: 0.4µs (uncoded), 4µs (coded)
Range resolution: 30 m
Pulse repetition frequency: 10 kHz
Unambiguous range: 15 km
Folding velocity: 10 m/s (uncoded), 5 m/s (coded)
The Galileo radar
The ESTEC-funded 94-GHz Galileo radar at Chilbolton is well suited to cloud measurements: its shorter wavelength (3.2mm) makes it particularly sensitivity to cloud droplets and ice particles. The instrument has full Doppler capability, enabling high-resolution measurements to be made of the spectrum of particle fall speeds.
The non-Rayleigh component to the reflectivity and Doppler weighting for large snowflakes (~1mm or bigger) allow important information about ice particle shape and size to be derived.
Frequency: 94.00 GHz
Transmit power: 1.6 kW peak pulse
Antenna: 0.46 m diameter dish
Pulse width: 0.5µs
Range resolution: 60 m
Pulse repetition frequency: 6.25 kHz
Unambiguous range: 24 km
Folding velocity: 5 m/s