Sea surface emissivity observations at L-band: first results of the Wind and Salinity Experiment WISE 2000

Sea surface salinity can be measured by passive microwave remote sensing at L-band. In May 1999, the European Space Agency (ESA) selected the Soil Moisture and Ocean Salinity (SMOS) Earth Explorer Opportunity Mission to provide global coverage of soil moisture and ocean salinity. To determine the effect of wind on the sea surface emissivity, ESA sponsored the Wind and Salinity Experiment (WISE 2000). This paper describes the field campaign, the measurements acquired with emphasis in the radiometric measurements at L-band, their comparison with numerical models, and the implications for the remote sensing of sea salinity.Peer ReviewedPostprint (published version

Radiation measurements during CLARE '98 : an overview

During CLARE’98 several radiometers were operated. In this paper an overview of the instruments operated by KNMI, TUE and TUD/IRCTR is given. This includes the net- and shortwave radiometers operated by KNMI and the sky temperature observations as measured by two IR-radiometers. One IR-radiometer was pointing vertically upwards, the second instrument was mounted in the 25m antenna dish of the Chilbolton radar. A 20/30/50 GHz microwave radiometer (20/30 GHz is on loan from ESTEC) was used to derive the column integrated liquid water and water vapour. Satellite data from the AVHRR instrument were collected and analysed. A time-lapse S-VHS video system was used to monitor the clouds at day-time. All systems were continuously operational during the CLARE’98 campaign, except for the upward pointing IR-radiometer, no technical problems were encountered. Data has been collected, calibrated and submitted to the CLARE’98 database

SMOS Validation and the COSMOS Campaigns

International audienceThe Soil Moisture and Ocean Salinity (SMOS) mission is a joint ESA-CNES (F)-CDTI (E) mission within the ESA Living Planet Program, and it was the second ESA Earth Explorer Opportunity Mission to be selected. The mission objectives of SMOS are to provide soil moisture and ocean salinity observations for weather forecasting, climate monitoring, and the global freshwater cycle. This paper will describe the scientific campaigns performed to date, as well as the plans for the on-orbit calibration and validation activitie

Soil moisture retrievals at L-band using a two step inversion approach (COSMOS/NAFE'05 experiment)

COSMOS (Campaign for validating the Operation of Soil Moisture and Ocean Salinity), and NAFE (National Airborne Field Experiment) were two airborne campaigns held in the Goulburn River catchment (Australia) at the end of 2005. These airborne measurements are being used as benchmark data sets for validating the SMOS (Soil Moisture and Ocean Salinity) ground segment processor over prairies and crops. This paper presents results of soil moisture inversions and brightness temperature simulations at different resolutions from dual-polarisation and multi-angular L-band (1.4 GHz) measurements obtained from two independent radiometers. The aim of the paper is to provide a method that could overcome the limitations of unknown surface roughness for soil moisture retrievals from L-band data. For that purpose, a two-step approach is proposed for areas with low to moderate vegetation. Firstly, a two-parameter inversion of surface roughness and optical depth is used to obtain a roughness correction dependent on land use only. This step is conducted over small areas with known soil moisture. Such roughness correction is then used in the second step, where soil moisture and optical depth are retrieved over larger areas including mixed pixels. This approach produces soil moisture retrievals with root mean square errors between 0.034 m3 m−3 and 0.054 m3 m−3 over crops, prairies, and mixtures of these two land uses at different resolutions

Radiation measurements during CLARE '98 : an overview

During CLARE’98 several radiometers were operated. In this paper an overview of the instruments operated by KNMI, TUE and TUD/IRCTR is given. This includes the net- and shortwave radiometers operated by KNMI and the sky temperature observations as measured by two IR-radiometers. One IR-radiometer was pointing vertically upwards, the second instrument was mounted in the 25m antenna dish of the Chilbolton radar. A 20/30/50 GHz microwave radiometer (20/30 GHz is on loan from ESTEC) was used to derive the column integrated liquid water and water vapour. Satellite data from the AVHRR instrument were collected and analysed. A time-lapse S-VHS video system was used to monitor the clouds at day-time. All systems were continuously operational during the CLARE’98 campaign, except for the upward pointing IR-radiometer, no technical problems were encountered. Data has been collected, calibrated and submitted to the CLARE’98 database

The CoSMOS L-band experiment in Southeast Australia

International audienc

Soil moisture estimates from the SMOS validation rehearsal campaign in Valencia using EMIRAD airborne measurements

International audienc

Sea surface emissivity observations at L-band: first results of the Wind and Salinity Experiment WISE 2000

Includes bibliographical references.Sea surface salinity can be measured by passive microwave remote sensing at L-band. In May 1999, the European Space Agency (ESA) selected the Soil Moisture and Ocean Salinity (SMOS) Earth Explorer Opportunity Mission to provide global coverage of soil moisture and ocean salinity. To determine the effect of wind on the sea surface emissivity, ESA sponsored the Wind and Salinity Experiment (WISE 2000). This paper describes the field campaign, the measurements acquired with emphasis in the radiometric measurements at L-band, their comparison with numerical models, and the implications for the remote sensing of sea salinity.The WISE 2000 campaign was supported by the European Space Agency under ESTEC Contract 14188/00/NL/DC. The numerical simulations have been performed under ESTEC Salinity Study 3618. The implementation of the L-band radiometer of the Polytechnic University of Catalonia has been supported by the Spanish government under Grant CICYT TIC99-1050-C03-01. The French moorings were supported by the Centre National d’Études Spatiales

A short study of the anisotropic resistance in carbon fibre composites

Appendix added September 1978Available from British Library Document Supply Centre- DSC:2265.63F(BR--100258) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo