New Zealand National-Scale Beach Topography Dataset (30 m): A Fusion of ICESat-2 and Sentinel-2

Description:

This dataset provides a seamless, national-scale beach topography product for New Zealand at a spatial resolution of 30 meters.

Key Method:

The topography was reconstructed using a machine learning framework (XGBoost) that fuses ICESat-2 laser altimetry control points with Sentinel-2 multispectral time-series features. The model specifically targets and fills the "NoData" voids in the DeltaDTM dataset.

Specifications:

• Region: New Zealand Coastline

• Resolution: ~1 arc-second

• Coordinate System: GCS_WGS_1984 (Geographic Coordinate System)

• Vertical Datum: EGM2008

• Time Period: Represents the composite state from 2018–2023.

Accuracy:

Validated against airborne LiDAR data, the dataset achieves an $R^2$ of 0.75 and an RMSE of 1.19 m.