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IEEE Transactions on Antennas and Propagation
Volume 47 Number 4, April 1999

Angle Measurement with a Phase MonopulseRadar Altimeter

Page 715.

Abstract:

It is possible to enhance the conventional satellite radar altimeter in such a way that the range measurement is accompanied by an angle measurement. This is useful if the applications of these altimeters are to be expanded to include nonlevel surfaces such as continental ice sheets and land. The angle measurement can be made in one or two directions through the inclusion of one or two additional antennas and receiver channels and the integration of complex "cross-channel" waveforms whose phase indicates the angle to the point of first reflection from the scattering surface. This paper develops the measurement concept and establishes the precision of the resulting elevation measurement through an analysis of the dominant sources of error within the instrument. It is shown through analysis and numerical simulation that elevation errors over a flat tilted diffusely scattering surface can be maintained below the 1-cm level. The impact of antenna pointing and surface roughness are considered.

References

1. G. S. Brown, "The average impulse response of a rough surface and its applications," IEEE Trans. Antennas Propagat., vol. AP-25, pp. 67-74, 1977.
2. D. B. Clelton, E. J. Walsh, and J. L. MacArthur, "Pulse compression and sea level tracking in satellite altimetry," J. Atmospheric Oceanic Tech., vol. 6, no. 3, pp. 407-438, June 1989.
3. H. J. Zwally, "Growth of Greenland ice sheet: Interpretation," Science, vol. 246, pp. 1589-1591, 1989.
4. R. Warrick and J. Oerlemans, "Sea level rise," in Climate Change, The IPCC Scientific Assessment.Cambridge, U.K.: Cambridge Univ. Press, 1990, pp. 261-281.
5. J. Oerlemans, "Possible changes in the mass balance of the Greenland and Antarctic ice sheets and their effects on sea level," in Climate and Sea Level Change.Cambridge, U.K.: Cambridge Univ. Press, 1993, pp. 144-161.
6. D. J. Wingham, C. G. Rapley, and J. G. Moreley, "Improved resolution ice sheet mapping with satellite radar altimeters," EOS, vol. 74, no. 10, pp. 113, 116.
7. H. J. Zwally, J. A. Major, A. C. Brenner, and R. A. Binschadler, "Ice measurements by Geosat radar altimeter," Johns Hopkins APL Tech. Dig., vol. 8, no. 2, pp. 251-254.
8. C. J. Choe and B. E. Schutz, "Estimation of ice sheet surface elevation change from the EOS laser altimeter satellite (ICESAT) crossover simulations," Advances Astronautical Sci., vol. 93, pp. 1623-1635,1996.
9. J. R. Jensen and R. K. Raney, "Multimission radar altimeter: Concept and performance," in Proc. Int. Geosci. Remote Sensing Symp. IGARSS'96, Lincoln, NE, May 1996, pp. 2279-2281.
10. R. K. Raney, "The delay/Doppler radar altimeter," IEEE Trans. Geosci. Remote Sensing, vol 36, pp. 1578- 1588, Sept. 1998.
11. P. C. Marth et al., "Prelaunch performance of the NASA altimeter for the Topex/Poseidon project," IEEE Trans. Geosci. Remote Sensing, vol. 31, pp. 315-332, Mar. 1993.
12. C. R. Valverde, R. K. Stilwell, A. A. Russo, and T. R. McKnight, "The S-band beacon receiver for the midcourse space experiment," Johns Hopkins APL Tech. Dig., vol. 15, no. 1, Jan. 1994.
13. M. Abramowitz and I. Stegan, Handbook of Mathematical Functions.New York: Dover, 1965.
14. D. Middleton, An Introduction to Statistical Communication Theory.Los Altos, CA: Peninsula, 1987.
15. C. H. Davis and R. K. Moore, "A combined surface and volume scattering model for ice-sheet radar altimetry," J. Glaciology, vol. 39, pp. 675-686, 1993.