volume | PIER Journals

Abstract

Operating frequencies for passive remote sensing have been extended to millimeter and sub-millimeter wave regions in recent years. Due to relatively shorter wavelengths, narrower beam widths can be achieved under antenna size limitations. In turn, better spatial resolution can be achieved, which is especially important for sensors in geostationary orbit. There are several mission proposals for millimeter and sub-millimeter wave payloads in geostationary orbit, e.g., Geostationary Observatory for Microwave Atmospheric Sounding (GOMAS) proposed by European countries, Geosynchronous Microwave (GEM) Sounder/Imager Observation System proposed by USA, the next generation Chinese geostationary orbit meteorological satellite FY-4, etc. The feasibility study of geostationary microwave payloads and simulation of millimeter and sub-millimeter wave atmospheric sounding data is currently underway. Many measures evaluate the efficacy of atmospheric sounding data, one of which is the Degrees of Freedom for Signal (DFS). It is independent of specific regression algorithm thus able to offer an objective measure for performance comparison and channel parameter optimization. In this paper, the DFS of a set of millimeter wave (50~70 GHz, 118 GHz, 183 GHz) and sub-millimeter wave (380 GHz, 425 GHz) sounding channels is analyzed. The DFS improvement with increasing bandwidth is given; results suggest that broader channel bandwidth will improve the efficacy and retrieval performance of the future geostationary orbit millimeter and sub-millimeter wave radiometers.

1., WMO report SAT-21, "Statement of guidance regarding how well satellite capabilities meet WMO user requirements in several application areas,", WMO TD No. 992, Geneva, Switzerland, 2000. Google Scholar

2. Lambrigtsen, B. H., S. T. Brown, S. J. Dinardo, P. P. Kangaslahti, A. B. Tanner, and W. J.Wilson, "Progress in developing GeoSTAR --- A microwave sounder for GOES-R," Proceedings of SPIE, 1-9, Aug. 2005. Google Scholar

2. Carlstrom, A., J. Christensen, J. Embretsen, A. Emerich, and P. Maagt, "A geostationary atmospheric sounder for now-casting and short-range weather forecasting," Proceedings of SPIE, Vol. 5882, 1-4, 2009. Google Scholar

4. Gasiewski, A. J., A. Voronovich, B. L. Weber, B. Standkov, M. Klein, R. J. Hill, and J. W. Bao, "Geosynchronous microwave (GEM) sounder/imager observation system simulation," Proceedingss of IGARSS 2003, 1209-1211, Jul. 2003. Google Scholar

5. Bizzarri, B., A. J. Gasiewski, and D. Staelin, "Observing rain by millimetre --- Submillimetre wave sounding from geostationary orbit," Series on Advances in Global Change Research, Ch. 50, 675-692, Springer, New York, 2007. Google Scholar

6. "Statement of guidance regarding how well satellite capabilities meet WMO user requirements in several application areas,", WMO Report, WMO TD No. 992 (Sat-22), Geneva, Switzerland, 2000.
doi:10.1002/qj.49711649209 Google Scholar

7. Eyre, J. R., "The information content of data from satellite sounding systems: A simulation study," Quarterly Journal of the Royal Meteorological Society, Vol. 116, 401-434, Dec. 2006.
doi:10.1175/1520-0450(1993)032<1092:EEDDIA>2.0.CO;2 Google Scholar

8. Purser, R. J. and H.-L. Huang, "Estimating effective data density in a satellite retrieval or an objective analysis," Journal of Applied Meteorology, Vol. 32, 1092-1107, Jun. 1993.
doi:10.1007/BF01029788 Google Scholar

9. Huang, H.-L. and R. J. Purser, "Objective measures of the information density of satellite data," Meteorology and Atmospheric Physics, Vol. 60, 105-117, Mar. 1996.
doi:10.1117/12.256110 Google Scholar

10. Rodgers, C. D., "Information content and optimization of high spectral resolution measurements," Proceedings of SPIE, Vol. 2830, 136-147, Oct. 1996. Google Scholar

11. Klein, M. and A. J. Gasiewski, "The sensitivity of millimeter and sub-millimeter frequencies to atmospheric temperature and water vapor variations," Journal of Geophysical Research, Vol. 13, 17481-17511, Jul. 2000.
doi:10.1109/TGRS.2003.810926 Google Scholar

12. Lipton, A. E., "Satellite sounding channel optimization in the microwave spectrum," IEEE Transactions on Geoscience and Remote Sensing, Vol. 41, 761-781, Apr. 2003.
doi:10.1175/JAM2438.1 Google Scholar

13. Prigent, C., J. R. Pardo, and W. B. Rossow, "Comparisons of the millimeter and submillimeter bands for atmospheric temperature and water vapor soundings for clear and cloudy skies," Journal of Applied Meteorology and Climatology, Vol. 45, 1622-1633, Dec. 2006. Google Scholar

14. Bizzarri, B., "Geostationary observatory for microwave atmospheric sounding," Report to the Second Call for Proposals for ESA Earth Explorer Opportunity Missions, 2002. Google Scholar

15. Borbas, E. E., S. W. Seemann, H.-L. Huang, J. Li, and W. P. Menzel, "Global profile training database for satellite regression retrievals with estimates of skin temperature and emissivity," Proceedings of the XIV. International ATOVS Study Conference, 763-770, May 2005. Google Scholar

16. Peckham, G. E., "Multiresolution analysis, entropic information and the performance of atmospheric sounding radiometers," Quarterly Journal of the Royal Meteorological Society, Vol. 126, 2933-2949, Apr. 2000. Google Scholar

Dr. Haibo Zhao

Dr. Cheng Zheng

Dr. Yongfang Zhang

Dr. Bin Liang

Dr. Naiming Ou

Dr. Jungang Miao