Geraint Vaughan, Emily Norton

The Facility for Ground-based Atmospheric Measurements (FGAM) mobile wind profiler is a 'clear-air' UHF Doppler radar system designed by Degreane Horizon to measure both wind speed and direction 24 hours a day under all weather conditions. 'Clear air' radars detect small irregularities in backscattered signals due to refractive index inhomogenieties caused by turbulence. In the lower troposphere the refractive index inhomogeneities are mainly produced by humidity fluctuations. The 'clear-air' Doppler shift provides a direct measurement of the mean radial velocity along the radar beam.UHF radars also observed strong echoes from precipitation. The wind profiler operatres at 1290 MHz with a peak power of 3.5 kW and beam width of 8.5^o. The radar consists of three panels to emit and receive three separate beams, each panel being an array of 64 dipole antennas. The vertical beam measures the vertical component of the wind and the two at elevation of 73^o and orthogonal azimuths sample radial velocities that have contributions from both vertical and horizontal wind components to enable full wind vectors to be calculated.

Contents.

• Photos
• Instrument Specifications
• Sample data

Operation requirements

Wind profiler folds up onto a compact trailer

weighing ~ 1 tonne that can be towed behind a vehicle such as a Land Rover

Operational dimension - L x W = 7.65 x 4.2 m

Packing up ~ 4 hours, Set-up time ~ 1 day

Power requirements two 13 A plug sockets

Sample measurements from TORCH 2003.

Maintained by: Emily Norton