Wind direction azimuthal signature in the Stokes emission vector from the ocean surface at microwave frequencies

Camps, Adriano; Reising, Steven C.

doi:10.1002/mop.1198

Cited by 12 publications

(9 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, these models have been developed or tuned at higher frequencies, typically 19 and 37 GHz. Therefore, the solid lines have been computed using a simple, fast, and accurate extended Kirchhoff model under the stationary phase approximation [14] that describes well the incidence angle dependence at L-band, and also the 19 and 37 GHz Jet Propulsion Laboratory measurements. The sea foam effects at L-band are hard to model.…”

Section: A Incidence Angle and Azimuth Signaturesmentioning

confidence: 99%

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

Camps

Font

Etcheto

et al. 2002

IEEE Trans. Geosci. Remote Sensing

View full text Add to dashboard Cite

Abstract-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.

show abstract

Section: A Incidence Angle and Azimuth Signaturesmentioning

confidence: 99%

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

Camps

Font

Etcheto

et al. 2002

IEEE Trans. Geosci. Remote Sensing

View full text Add to dashboard Cite

show abstract

“…. Although not very accurate at L-band, an extended Kirchhoff model under the stationary phase approximation [9] has been used to plot the solid lines overlaid in Fig. 7.…”

Section: Low-to-moderate Wind Conditions-mentioning

confidence: 99%

Sea surface emissivity at L-band: results of the WInd and Salinity Experiments WISE 2000 and 2001 and preliminary results from FROG 2003

et al. 2004

View full text Add to dashboard Cite

Two field experiments named WISE (WInd and Salinity Experiment) were sponsored by the European Space Agency (ESA) to better understand the wind and sea state effects on the L-band brightness temperatures. They took place at the Casablanca oil rig located in the North Mediterranean Sea, 40 km off shore the Ebro river deltaSpanish National funds, a third field experiment named FROG (Foam, Rain, Oil slicks and GPS reflectometry) took place at the Ebro river delta, to measure the phenomena that were not completely understood during the WISE field experiments, mainly the effect of foam and rain. In order to achieve the objectives of the WISE field experiments the LAURA L-band fully polarimetric radiometer from the Technical University of Catalonia (UPC) was mounted on the Casablanca oil-rig at the 32 meters deck above the sea surface, pointing to the North and North-West, in the direction of the dominant winds. In this paper we present the results of the first study to determine the relationship between the brightness temperature and the sea state.

show abstract

“…The percentage errors as a result of assuming constant atmospheric downwelling temperature are less than 2% and 5% of the incidence angle sensitivities, and , respectively. After accounting for the reflected downwelling radiation, the incidence angle sensitivities of the measured ocean surface emission were modeled using the Kirchhoff method with the stationary phase approximation as formulated by Camps and Reising [7]. To avoid the need to calculate for every measured incidence angle, and since the variations in incidence angle were less than , the values were assumed to be constant over this range, and equal to their average values.…”

Section: B Pitch Angle Correctionmentioning

confidence: 99%

Effects of air-sea interaction parameters on ocean surface microwave emission at 10 and 37 GHz

Aziz

Reising

Asher

et al. 2005

IEEE Trans. Geosci. Remote Sensing

View full text Add to dashboard Cite

Abstract-WindSat, the first polarimetric radiometer on orbit, launched in January 2003, provides the promise of passive ocean wind vector retrievals on a continuous basis, simultaneous with the retrieval of many other geophysical variables such as sea surface temperature, atmospheric water vapor, cloud liquid water, and sea ice extent and concentration. WindSat also serves as risk reduction for the upcoming National Polar-orbiting Operational Environmental Satellite System (NPOESS) Conical Scanning Microwave Imager/Sounder (CMIS). Since the dependence of microwave brightness temperatures on wind direction is small relative to that of other parameters such as wind speed, wind direction retrieval relies on increasingly accurate knowledge of the ocean surface microwave emission, which depends upon surface properties such as roughness and foam due to wave breaking. Coordinated near-surface measurements of ocean surface microwave emission and air-sea interaction parameters are needed to quantify the effects of the processes mentioned above in surface emission models to improve the accuracy of wind vector retrievals. Such coordinated observations were performed during the Fluxes, Air-Sea Interaction, and Remote Sensing (FAIRS) experiment conducted on the R/P Floating Instrument Platform (FLIP) in the northeastern Pacific Ocean during the Fall of 2000. X-and Ka-band partially polarimetric radiometers were mounted at the end of the port boom of R/P FLIP to measure ocean surface emission at incidence angles of 45 , 53 , and 65 . A bore-sighted video camera recorded the fractional area of foam in the field of view of the radiometers. Air-sea interaction parameters that were measured concurrently include wind speed, friction velocity, heat fluxes, and significant wave height. The measured dependence of ocean surface emissivity on wind speed and friction velocity is in good agreement with, and extends, earlier observations and empirical models based on satellite data. Concurrent radiometric measurements and fractional Manuscript received March 31, 2004; revised March 7, 2005. This was supported in part by the Department of the Navy, Office of Naval Research under Awards N0014-00-1-0280 and N00014-03-1-0044 to the University of Massachusetts, Award N0014-00-1-0152 to the University of Washington, and Award N0014-00-WX2-1032 to the Naval Research Laboratory, and in part by the National Polar-orbiting Operational Environmental Satellite System (NPOESS) area foam coverage data strengthen the possibility of retrieval of sea surface foam coverage using airborne or spaceborne radiometry. The dependence of emissivity on atmospheric stability is shown to be much smaller than the dependence of emissivity on wind speed. Analysis of emissivity dependence on atmospheric stability alone was inconclusive, due to the variation in atmospheric stability with wind speed. The effect of long-wave incidence angle modulation on sea surface emissivity for near-surface measurements was found to be negligible when emissivity measurements were averag...

show abstract

Wind direction azimuthal signature in the Stokes emission vector from the ocean surface at microwave frequencies

Cited by 12 publications

References 19 publications

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

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

Sea surface emissivity at L-band: results of the WInd and Salinity Experiments WISE 2000 and 2001 and preliminary results from FROG 2003

Effects of air-sea interaction parameters on ocean surface microwave emission at 10 and 37 GHz

Contact Info

Product

Resources

About