Test datasets for "A modular toolkit for block-based spatially explicit spectral analysis of digital elevation models": 1 m resolution LiDAR DEMs (mountainous slope and Podskalie case study)
Description
This dataset validates FFT Tools, a modular Rust toolkit for spatially explicit spectral analysis of Digital Elevation Models (DEMs). The research addresses spectral leakage and non-stationarity in geomorphometry by combining block-based localized Fourier decomposition with a thin-plate spline (TPS) extrapolation strategy. This approach enables the resolution of anisotropic landform organization and the discrimination of lithologically controlled textures without boundary-induced artifacts. The archive contains four DEM datasets in GeoTIFF (.tif) format used in Sections 4.1–4.3 of the manuscript: slope.tif: A 1 m resolution LiDAR-derived DEM representing a mountainous slope segment, used for spectral characterization and power spectral density (PSD) analysis (Section 4.1). podskalie.tif: A 1 m resolution LiDAR-derived DEM from the Podskalie area, used as the primary case study for scale-specific reconstruction and quantitative comparison (Section 4.2). compareDMR5.tif: A 25 m resolution DEM derived by resampling a 1 m LiDAR DEM, representing the northwestern part of Slovakia. This dataset serves as the high-quality reference in the comparative spectral analysis (Section 4.3). compareSRTM.tif: A 25 m resolution DEM derived from SRTM 1 arc-second data over the same region in northwestern Slovakia. This dataset is used for scale-resolved comparison against the LiDAR-derived reference (Section 4.3). All datasets were processed using the FFT Tools framework with consistent parameter settings. The 1 m LiDAR datasets were analyzed using an outer tapering strategy with residual reconstruction to preserve the full interior signal. The 25 m datasets were evaluated using identical grid spacing to isolate sensor-related quality differences from resolution effects. Together, these benchmarks demonstrate the toolkit’s capacity to characterize scale-dependent terrain structure, assess DEM fidelity, and support physically interpretable geomorphometric analysis. The data are intended for use with the FFT Tools library to replicate the spectral decomposition, comparison, and filtering workflows described in the manuscript.