Geoskill: Open Elevation

Query elevation data by latitude and longitude using the free Open-Elevation API with single-point or batch CSV inputs, outputting CSV or JSON without an API...

ruiduobao@ruiduobao

Install

openclaw skills install @ruiduobao/geoskill-open-elevation

Open-Elevation

Query elevation (in meters) for any lat/lon coordinate on Earth using the free, public Open-Elevation API. No API key required.

Features

Single-point elevation lookup
Batch queries from CSV files (up to 100 points per API call)
Automatic chunking for large datasets
CSV and JSON output
Input validation for coordinates

Usage

bash

# Single point
python scripts\open-elevation.py lookup --lat 39.9042 --lon 116.4074

# JSON output
python scripts\open-elevation.py lookup --lat 39.9042 --lon 116.4074 --json

# Batch from CSV
python scripts\open-elevation.py batch --input coords.csv --output results.csv

# Batch to JSON
python scripts\open-elevation.py batch --input coords.csv --output results.json --json

Installation

bash

pip install requests>=2.28.0 tqdm
# Or: pip install -r scripts/requirements.txt

Parameters

`lookup`

Argument	Required	Default	Description
`--lat`	Yes	—	Latitude (-90 to 90)
`--lon`	Yes	—	Longitude (-180 to 180)
`--json`	No	false	Output as JSON

`batch`

Argument	Required	Default	Description
`--input`	Yes	—	Input CSV path (must contain `lat`/`lon` or `latitude`/`longitude` columns)
`--output`	Yes	—	Output file path
`--json`	No	false	Output as JSON instead of CSV
`--chunk`	No	100	Points per API request (max 100)

Data Source

API: Open-Elevation
Endpoint: https://api.open-elevation.com/api/v1/lookup
Coverage: Global
License: Public domain
Cost: Free, no key required
Underlying data: SRTM (Shuttle Radar Topography Mission), AW3D30 (ALOS World 3D - 30m), and other sources
CRS: WGS84 (EPSG:4326)
Spatial resolution: ~30m (SRTM 1-arc second), varies by region
Rate limit: Max 100 points per API request; be respectful of the public service
Timeout: Default 30s per request; configurable via --timeout flag

Output Schema

CSV columns: latitude, longitude, elevation

JSON format:

json

{
  "results": [
    {"latitude": 39.9042, "longitude": 116.4074, "elevation": 43.5}
  ]
}

Ocean / Bathymetry Handling

Ocean areas return elevation of 0 (sea level) or negative values (bathymetry) depending on data availability
SRTM does not cover open ocean; ocean points may return 0

Citation

If you use SRTM data in publications, please cite:

bibtex

@misc{srtm2000,
  title = {Shuttle Radar Topography Mission (SRTM) Global Data},
  author = {{NASA Jet Propulsion Laboratory}},
  year = {2000},
  howpublished = {\url{https://www2.jpl.nasa.gov/srtm/}},
  note = {Accessed: YYYY-MM-DD}
}

Visualization

Plot elevation profiles with matplotlib: plt.plot(distance, elevation)
Create DEM heatmaps with imshow() using terrain colormaps (cmap='terrain')
Overlay on maps with contextily or folium

Troubleshooting

Error	Cause	Solution
`ConnectionError`	Network issue	Check internet, retry
`HTTP 429`	Rate limit	Wait 60s, retry
`ValueError`	Invalid input	Check parameter format
Empty output	No data	Try different parameters
`ModuleNotFoundError`	Missing dep	Run pip install
Timeout	Slow network	Increase `--timeout` value
All zeros in ocean	No SRTM coverage	Expected behavior for ocean points

Advanced Usage

Large Batch Query with Retry

python

import csv, time, subprocess
with open('points.csv') as f:
    reader = csv.DictReader(f)
    for row in reader:
        for attempt in range(3):
            result = subprocess.run(
                ['python', 'scripts/open_elevation.py', 'lookup',
                 '--lat', row['lat'], '--lon', row['lon']],
                capture_output=True, text=True
            )
            if result.returncode == 0:
                break
            time.sleep(2 ** attempt)

CI/CD Integration (GitHub Actions)

yaml

# .github/workflows/elevation-update.yml
name: Elevation Data Update
on:
  workflow_dispatch:
jobs:
  query:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: '3.11'
      - run: |
          python scripts\open-elevation.py batch \
            --input points.csv --output elevations.json

PostgreSQL/PostGIS Import

bash

python scripts\open-elevation.py batch --input points.csv --output elevations.json

# Convert to CSV then import
python -c "import json, csv; d=json.load(open('elevations.json')); 
csv.writer(open('elev.csv','w',newline='')).writerows(
  [('lat','lon','elevation')] + [(p['lat'],p['lon'],p['elevation']) for p in d]
)"
psql -d gis_db -c "\COPY elevations(lat, lon, elevation) FROM 'elev.csv' CSV HEADER"

Performance Tips

Batch mode accepts up to 100 points per request; chunk large files
Add sleep 1 between batches to respect rate limits
Ocean coordinates return 0m elevation — filter with WHERE elevation != 0

中文说明

使用免费的 Open-Elevation 公开 API 查询任意经纬度的海拔高度（米）。无需 API 密钥。

功能

单点高程查询
从 CSV 文件批量查询（每次 API 调用最多 100 点）
大数据集自动分块
支持 CSV 和 JSON 输出
坐标输入验证

使用方法

bash

# 单点查询
python scripts\open-elevation.py lookup --lat 39.9042 --lon 116.4074

# JSON 输出
python scripts\open-elevation.py lookup --lat 39.9042 --lon 116.4074 --json

# 批量查询
python scripts\open-elevation.py batch --input coords.csv --output results.csv

# 批量 JSON 输出
python scripts\open-elevation.py batch --input coords.csv --output results.json --json

数据来源

API: Open-Elevation
端点: https://api.open-elevation.com/api/v1/lookup
覆盖范围: 全球
许可证: 公有领域
费用: 免费，无需密钥
底层数据: SRTM (航天飞机雷达地形测绘任务)、AW3D30 (ALOS World 3D - 30m) 等
坐标系: WGS84 (EPSG:4326)
空间分辨率: ~30m (SRTM 1角秒)，因地区而异
速率限制: 每次 API 请求最多 100 点；请尊重公共服务
超时: 默认 30 秒/请求；可通过 --timeout 参数配置

输出格式

CSV 列: latitude, longitude, elevation

JSON 格式:

json

{
  "results": [
    {"latitude": 39.9042, "longitude": 116.4074, "elevation": 43.5}
  ]
}

海洋/水深处理

海洋区域返回海拔 0（海平面）或负值（水深），取决于数据可用性
SRTM 不覆盖开阔海洋；海洋点可能返回 0

引用格式

如果发表使用 SRTM 数据，请引用:

bibtex

@misc{srtm2000,
  title = {Shuttle Radar Topography Mission (SRTM) Global Data},
  author = {{NASA Jet Propulsion Laboratory}},
  year = {2000},
  howpublished = {\url{https://www2.jpl.nasa.gov/srtm/}},
  note = {Accessed: YYYY-MM-DD}
}

可视化

使用 matplotlib 绘制高程剖面: plt.plot(distance, elevation)
使用 imshow() + terrain 色标 (cmap='terrain') 创建 DEM 热力图
使用 contextily 或 folium 叠加到地图上

故障排除

错误	原因	解决方案
`ConnectionError`	网络问题	检查网络，重试
`HTTP 429`	速率限制	等待 60 秒后重试
`ValueError`	无效输入	检查参数格式
空输出	无数据	尝试不同参数
`ModuleNotFoundError`	缺少依赖	运行 pip install
超时	网络慢	增加 `--timeout` 值
海洋区域全为 0	SRTM 无覆盖	海洋点的预期行为