Data were collected by the Chilbolton Facility for Atmospheric and Radio Research (CFARR) Radiometrics Radiometer from the 23rd of August 2007 to the present at Chilbolton, Hampshire. The dataset contains measurements of the total liquid water at zenith, together with the vertical profile of water vapour density. Accuracy of integrated water vapour (IWV) retrieval: ~1 – 2 mm Accuracy of total liquid water path (LWP) retrieval: ~15% in non-precipitating conditions.

In June 2006 the NERC-funded Network for Calibration and Validation of EO data (NCAVEO) organised a cal-val field experiment in Chilbolton, north Hampshire involving 48 scientists from 20 organisations (click for list). The aim was to undertake a validation exercise based on the protocols and methods developed by the Validation of Land European Remote Sensing Instruments (VALERI) project, but modified as necessary for UK conditions. The experiment is a scoping exercise for the establishment of one or more VALERI sites in the UK as well as an opportunity to learn and share best practice amongst NCAVEO partners and the wider community. The initial plan was to base the experiment at the Barton Bendish test site in East Anglia, but the absence of on-site instrumentation coupled with uncertainty about access to this site and its distance from the main research groups led to a search for other suitable sites. The one chosen was centred on the Services and Technology Facilities Council Chilbolton Facility for Atmospheric and Radio Research (CFARR), approximately 45 km north of Southampton (Figure 1). CFARR comprises a number of state-of-the-art instruments for measuring atmospheric properties, including the 25 metre diameter Chilbolton dish, a 3 GHz doppler-polarisation radar, 1275 MHz clear air radar and a UV vertical sounding LiDAR In addition, the site has a full suite of continuously operating meteorological instruments. Datasets collected include Digi HRG data, remotely sensed data from 2 aircrafts, ground spectral data , atmospheric data, biophysical data, and fluvial geomorphological data.

The Icelandic Volcano, Eyjafjallajokull, started erupting on 14th April 2010. The volcanic ash cloud produced covered much of Northern Europe for several weeks causing extensive disruption to air travel. The UK and European atmospheric communities had many instruments - both airborne and ground-based, remote sensing and in-situ - taking measurements of the ash cloud throughout this period. This dataset contains Leosphere and Halo Doppler Lidar images from the Chilbolton Observatory, Hampshire.

Data were collected by the Chilbolton Facility for Atmospheric and Radio Research (CFARR) Meteorological Sensor from 2001 to present at Chilbolton, Hampshire. The standard meteorological measurements are made at Chilbolton in support of all experiments at the Observatory. The data are automatically recorded every 10 seconds from a range of different sensors. The dataset contains measurements including temperature, dew point, pressure, wind speed and wind direction.

Data were collected by the Chilbolton Facility for Atmospheric and Radio Research (CFARR) Meteorological Sensor from 2003 to 2007 at Sparsholt College, Hampshire. The standard meteorological measurements were made in support of all experiments at the Chilbolton Observatory. The data are automatically recorded every 10 seconds from a range of different sensors. The dataset contains measurements including temperature, dew point, pressure, wind speed and wind direction.

Data were collected by the Chilbolton Facility for Atmospheric and Radio Research (CFARR) Meteorological Particle Sensor from 2009 to present. During this time the particle sensor was at Chilbolton, Hampshire, whilst previously it had been positioned at Sparsholt College, Hampshire. The dataset contains measurements of the size of individual particulates including rain, snow, and hail, as well as estimates of drizzle, total rainfall and liquid water content.

The Convective Storm Initiation Project (CSIP) aimed to further the understanding of the mechanisms responsible for the initiation of precipitating convection in the maritime environment of southern England; i.e. to understand why convective clouds form and develop into precipitating clouds in a particular location. Data have been collected from the 13th June 2005 to the 25th August 2005 by the Ultra-violet Raman lidar at Chilbolton Observatory, Hampshire. The dataset contains measurements of attenuated backscatter coefficients of aerosols within the atmosphere, and humidity mixing ratios. Plots of the attenuated backscatter coefficient, and of the humidity mixing ratios, at different heights are also available.

Data were collected by the Chilbolton Facility for Atmospheric and Radio Research (CFARR) Visible Radiometer from 10th of May 2001 to the present at Chilbolton, Hampshire. The dataset contains measurements of high accuracy total global, or diffuse sky, solar radiation measurement research on a plane/level surface, for extreme temperature environments.

The Sparsholt College-South Wonston water station radio links data describe signal levels of several links at a frequency of 54 Ghz, which covered a path of 5km from the South Wonston water tower near the A34 to Sparsholt College. The data were collected between October 2002 and April 2005. The radio link between Sparsholt college and the Wonston water tower is used to investigate the effects of rain and sleet on radio signals.

The Convective Storm Initiation Project (CSIP) aimed to further the understanding of the mechanisms responsible for the initiation of precipitating convection in the maritime environment of southern England; i.e. to understand why convective clouds form and develop into precipitating clouds in a particular location. Data have been collected from the 6th July 2004 to the 29th July 2004 by the Ultra-violet Raman lidar at Chilbolton Observatory, Hampshire. The dataset contains measurements of attenuated backscatter coefficients of aerosols within the atmosphere, and humidity mixing ratios. Plots of the attenuated backscatter coefficient, and of the humidity mixing ratios, at different heights are also available.