For a more detailed description of the AIRS Level 2 retrieval 
          algorithm, please see:
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      Huang, Hung-Lung, Antonelli, P. 2001. Application of principal component 
         analysis to high- resolution infrared measurement compression 
         and retrieval. J. Appl. Met., 40, 365-388.
      Smith, W.L., Woolf, H.M. 1976. The use of eigenvectors of statistical 
         covariance matrices for interpreting satellite sounding radiometer 
         observations.  J. Atmos. Sci., 33, 1127-1140.
      Strow, L.L., Hannon, S.E., De Souza-Machado, S., Motteler, H.E., 
         Tobin, D. 2003. An overview of the AIRS radiative transfer model.  
         IEEE Trans. Geosci. Remote Sensing, 41, 303-313.
      Susskind, J., Barnet, C.D., Blaisdell, J.M. 2003. Retrieval of 
         atmospheric and surface parameters from AIRS/AMSU/HSB data in the 
         presence of clouds.  IEEE Trans. Geosci. Remote Sensing, 41, 390-409.
      Weisz, E., Huang,H-L, Li, J., Seemann, S., Borbas, E., Baggett, K., 
         Guan, L. 2004. IMAPP AIRS applications and products (Submitted for 
         publication to IEEE Trans. Geosci. Remote Sensing). 
      Huang, H-L, P. Yang, H.-L. Wei, B. A. Baum, Y.-X. Hu, P. Antonelli, 
          and S. A. Ackerman, "Retrieval of ice cloud properties from high 
          spectral resolution infrared observations",
          IEEE Trans. Geosci. Remote Sensing, vol. 42, pp. 842-853, 2004.
      Huang, H-L and W.L. Smith, 2004: Apperception of Clouds in AIRS Data. 
          Workshop on Assimilation of high spectral resolution sounders in NWP,
           June28- July 1, 2004, ECMWF Reading, UK.155-169.
      Huang, H-L, L. E. Gumley, K. Strabala, J. Li, E. Weisz, T. Rink, 
          K. C. Baggett, J. E. Davies, W. L. Smith, and J. C. Dodge, 2004: 
          International MODIS and AIRS Processing Package (IMAPP) -
          A Direct Broadcast Software Package for the NASA Earth Observing 
          System. Bulletin of the American Meteorological Society, Vol. 85, 
          Number 2, 159-161.
      Huang, H-L, W.L. Smith, J. Li, P. Antonelli, X. Wu, R.O. Knuteson, B. 
          Huang, B.J. Osborne, 2004: Minimum Local Emissivity Variance 
          Retrieval of Cloud Altitude and Emissivity Spectrum - Simulation and 
          Initial Verification. Accepted for publication, . J. Appl. Meteor.