THE LIMITING RESOLUTION OF ICE-SHEET ELEVATIONS DERIVED FROM PULSE-LIMITED SATELLITE ALTIMETRY

• Main Author: WINGHAM, DJ
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: INT GLACIOL SOC 1995
• Subjects: CONTINENTAL ICE; Ice Sheet
• Online Access: http://discovery.ucl.ac.uk/75778/

The problem of improving the spatial resolution of ice-sheet elevations derived from satellite-altimeter observations is investigated theoretically in two dimensions. An equation for the echo is described that allows the elevation to be determined by linear operations on the echo. An approximate solution of the equation is explored to illustrate the behaviour of the solution. The modifications necessary to consider a regularly sampled solution are described and the effects of echo fluctuations on the reconstructed surface are considered. Numerical examples are described. It is shown that, in general terms, the resolution may be limited be sampling or by echo fluctuations but that in the case of current practical measurements it is the sampling that determines the resolution. This resolution is smaller than has been considered possible hitherto. Limitations of the method are discussed together with extensions to a wider class of problems including three-dimensional reconstructions.