Homomorphism between cloudy and clear spectral radiance in the 800-900-cm(-1) atmospheric window region.

The sensitivity of a new algorithm for cloud detection over a sea surface has been assessed on the basis of extensive simulations of clear and cloudy radiance spectra, including water and ice and low- and high-altitude clouds. The new algorithm makes use of autocorrelation and cross correlation between an observed spectrum and either a synthetic or a laboratory spectrum and can be used to determine quantitatively the degree of homogeneity of two spectra in the 800-900-cm(-1) region (11.11-12.5 microm). The scheme is intended for high-spectral-resolution observations and could form the basis for an operational stand-alone cloud-detection algorithm for next-generation sounding spectrometers. Application of the scheme to real observations is presented and discussed.

[1]  P. Chylek,et al.  Infrared Emittance of Water Clouds , 1992 .

[2]  S. Warren,et al.  Optical constants of ice from the ultraviolet to the microwave. , 1984, Applied optics.

[3]  A. A. Chursin,et al.  The 1997 spectroscopic GEISA databank , 1999 .

[4]  D. J. Segelstein.  The complex refractive index of water , 1981 .

[5]  J. Salisbury,et al.  Emissivity of terrestrial materials in the 3–5 μm atmospheric window☆ , 1992 .

[6]  Hartmut H. Aumann,et al.  Atmospheric Infrared Sounder on the Earth Observing System , 1994 .

[7]  K. Masuda,et al.  Emissivity of pure and sea waters for the model sea surface in the infrared window regions , 1988 .

[8]  R. Norton,et al.  Analysis of spectra using correlation functions. , 1988, Applied Optics.

[9]  Graeme L. Stephens,et al.  A new polarized atmospheric radiative transfer model , 1991 .

[10]  Hirokazu Kobayashi,et al.  Satellite-borne high-resolution FTIR for lower atmosphere sounding and its evaluation , 1999, IEEE Trans. Geosci. Remote. Sens..

[11]  F. X. Kneizys,et al.  Line shape and the water vapor continuum , 1989 .

[12]  C. Serio,et al.  Cloud Detection Over Sea Surface by use of Autocorrelation Functions of Upwelling Infrared Spectra in the 800-900-cm(-1) Window Region. , 2000, Applied optics.

[13]  Shepard A. Clough,et al.  Simultaneous inversion for temperature and water vapor from IMG radiances , 2000 .

[14]  M. Iacono,et al.  Line-by-Line Calculations of Atmospheric Fluxes and Cooling Rates: Application to Water Vapor , 1992 .

[15]  Rolando Rizzi,et al.  Simulation of uplooking and downlooking high-resolution radiance spectra with two different radiative transfer models. , 2002, Applied Optics.