srtm 0.2.0

High-performance SRTM elevation data library

htg - High-performance SRTM Elevation Library

Python bindings for the htg Rust library, providing fast elevation queries from SRTM .hgt files.

Installation

pip install srtm

Quick Start

import srtm

# Create service with up to 100 cached tiles
service = srtm.SrtmService("/path/to/srtm", cache_size=100)

# Query elevation (Mount Fuji)
elevation = service.get_elevation(35.3606, 138.7274)
print(f"Elevation: {elevation}m")  # 3776

# Interpolated query for smoother results
elevation = service.get_elevation_interpolated(35.3606, 138.7274)
print(f"Elevation: {elevation:.2f}m")  # 3776.42

# Check cache performance
stats = service.cache_stats()
print(f"Cache hit rate: {stats.hit_rate:.1%}")

Utility Functions

import srtm

# Convert coordinates to filename
filename = srtm.lat_lon_to_filename(35.5, 138.7)
print(filename)  # "N35E138.hgt"

# Parse filename to coordinates
coords = srtm.filename_to_lat_lon("N35E138.hgt")
print(coords)  # (35, 138)

# Void value constant
print(srtm.VOID_VALUE)  # -32768

SRTM Data

Download SRTM .hgt files from:

• https://dwtkns.com/srtm30m/
• https://earthexplorer.usgs.gov/

Performance

This library uses Rust for the core implementation, providing:

• <10ms response time for cached tiles
• Memory-mapped I/O for fast file access
• LRU caching to bound memory usage

License

MIT