README.md

metadata

license: other
task_categories:
  - other
tags:
  - elevation
  - srtm
  - geotiff
  - dem
  - terrain
size_categories:
  - extra-extra-large-1M+

SRTM 30m Global Digital Elevation Model

NASA Shuttle Radar Topography Mission (SRTM) 30m resolution global DEM, converted to Cloud Optimized GeoTIFF format.

Dataset Details

• Source: NASA SRTM GL1 v3 (Global 1 arc-second, ~30m resolution)
• Coverage: 80% of land surface between 56°S and 60°N
• Resolution: ~30 meters (1 arc-second)
• Format: GeoTIFF with Deflate compression, 16-bit signed integer
• Files: 14,296 tiles, ~65 GB total
• Tile naming: N{lat}E{lon}.tif or S{lat}W{lon}.tif (1°×1° tiles)
• Internal tiling: 256×256 pixels, 15×15 grid per file (225 internal tiles)
• NoData value: -32768
• Horizontal datum: WGS 84

Usage

Via OpenZenith API

GET https://openzenith.pages.dev/api/elevation?lat=28.5&lon=96.5

Direct download

from huggingface_hub import hf_hub_download
path = hf_hub_download("aliasfox/srtm30m", "N28E096.tif", repo_type="dataset")

HTTP Range requests

Each GeoTIFF file supports HTTP Range requests. The first 4KB contains the IFD (Image File Directory) with tile offsets. Each 256×256 internal tile can be fetched individually (3-53 KB compressed).

File Structure

Each file covers a 1°×1° area:

• Image size: 3601×3601 pixels
• Pixel values: elevation in meters (Int16)
• Compression: Deflate (zlib)
• Internal tiles: 256×256 (225 tiles per file)