Filtering of digital terrain models by 2D Singular Spectrum Analysis

Singular Spectrum Analysis (SSA) has been approved as a model-free technique to analyse time series. SSA can solve different problems such as decomposition into a sum of trend, periodicities, and noise, smoothing, and others. In this paper, we validate abilities of 2D-SSA (the extension of SSA to analyse two-dimensional scalar fields) to treat digital terrain models (DTMs). The study is exemplified by a 30-arc-second digital elevation model of a part of South America derived from GTOPO30. Results demonstrate that 2D-SSA is an efficient method to denoise and generalise DTMs. It can be also used to decompose a topographic surface into components of continental, regional, and local scales.