# Source: MERIT DEM (Multi-Error-Removed Improved-Terrain DEM)
# Type: geotiff
# Catalog: Manual
# Created for: CBGB benchmark problems
# Note: Copernicus DEM 30m on Planetary Computer (cop-dem-glo-30) is a higher
#       resolution alternative. MERIT DEM is specifically referenced by CBGB.

source:
  id: merit-dem
  name: MERIT DEM v1.0.3
  type: geotiff
  url: http://hydro.iis.u-tokyo.ac.jp/~yamadai/MERIT_DEM/
  description: >
    MERIT DEM (Multi-Error-Removed Improved-Terrain DEM) is a high-accuracy
    global digital elevation model at 3 arc-second (~90m) resolution. It was
    developed by removing multiple error components from existing spaceborne
    DEMs (SRTM3 v2.1 and AW3D-30m v1). Error removal includes absolute bias,
    stripe noise, speckle noise, and tree height bias. The result is a
    significantly improved DEM suitable for global hydrological modeling and
    flood inundation mapping. Covers 90N-60S.
  provider: University of Tokyo (Dai Yamazaki Lab)
  license: CC-BY-NC-4.0
  metadata:
    connector_id: null
    tags:
    - DEM
    - Elevation
    - Terrain
    - Global
    - Raster
    - MERIT
    - Hydrology
    dataset:
      tier: 1
      thematic_group: Elevation & Terrain
      format: geotiff
      resolution: 3 arc-second (~90m)
      crs: EPSG:4326
      bands:
      - id: dem
        description: Elevation above EGM96 geoid (meters)
        dtype: float32
      temporal:
        range: 2018-01-01/2018-12-31
        frequency: static
        type: snapshot
        default_range: latest
      quality:
        methodology: >
          Multiple error removal applied to SRTM3 v2.1 and AW3D-30m v1.
          Removes absolute bias using ICESat points, stripe noise using
          wavelet decomposition, speckle noise using adaptive smoothing,
          and tree height bias using Global Forest Canopy Height data.
        accuracy: >
          Vertical accuracy RMSE ~2m in flat areas (compared to ~5m for
          raw SRTM). Significantly reduced systematic errors. See Yamazaki
          et al. 2017, Geophysical Research Letters 44(11).
        coverage: near-global (90N-60S)
      layout:
        type: tiled
        spatial:
          scheme: grid-5x5
        uri_template: http://hydro.iis.u-tokyo.ac.jp/~yamadai/MERIT_DEM/distribute/v1.0.3/{tile}.tar
        parameters:
        - var: tile
          description: 5x5 degree tile identifier (e.g., n30w090)
      access:
        type: http
        url: http://hydro.iis.u-tokyo.ac.jp/~yamadai/MERIT_DEM/
        notes: >
          Free download after registration. Tiles distributed as tar archives
          of GeoTIFF files. Also available on Google Earth Engine
          (MERIT/DEM/v1_0_3). For higher resolution (~30m), consider
          Copernicus DEM (planetary-computer-cop-dem-glo-30).
      related_sources:
      - planetary-computer-cop-dem-glo-30
      original_source_url: http://hydro.iis.u-tokyo.ac.jp/~yamadai/MERIT_DEM/
      homepage: http://hydro.iis.u-tokyo.ac.jp/~yamadai/MERIT_DEM/
      gee_asset_id: MERIT/DEM/v1_0_3
      cbgb_problems:
      - EBA_F5.2_A2