Atmospheric Instrument Suite

CAMRa is a 3 GHz S‑band radar mounted on a 25‑metre fully steerable antenna, offering exceptional sensitivity and high‑resolution observations of clouds and storms. Its dual‑polarisation capability enables measurement of hydrometeor shape and orientation, while full Doppler capability provides radial wind information.

The Chilbolton UV Raman lidar makes measurements of both elastically and inelastically (Raman) scattered radiation. The system transmits at a wavelength of 355 nm and measures cloud, water vapour and aerosol profiles.

The range of raingauges at Chilbolton Observatory includes:

• RAL Rapid Response Drop Counting rain gauges
• A Distromet RD-80 Impact Disdrometer
• A RW Munro 0.2mm Tipping Bucket rain gauge

The Chilbolton disdrometers provide an essential link between actual size measurements of rain drops and the drop size information derived from the 3 GHz CAMRa radar.

The Chilbolton sunphotometer measures aerosol optical thickness (AOT) in the wavelength range 340 – 1640 nm.

The Cimel CE318 sunphotometer measures the radiation received from the sun at 15 wavelengths in the wavelength range 340 nm to 1640 nm. It uses these measurements to deduce the aerosol optical thickness (AOT) of the atmosphere at these wavelengths. It order to do this reliably, there must be no cloud present in the direction of the sun for the duration of the measurements. If the sky is clear enough it can also derive other quantities such as particle size, real and imaginary components of refractive index and phase function at various wavelengths.