🌍 NDVI Calculation API using FastAPI & SentinelHub

This project provides a simple FastAPI-based API endpoint to calculate NDVI (Normalized Difference Vegetation Index) statistics over a given polygon using SentinelHub services.

📦 Features

• Accepts GeoJSON input to define an area of interest.
• Queries Sentinel-2 L2A data through SentinelHub.
• Calculates daily NDVI values for the given period (2022-01-01 to 2022-11-30).
• Returns histogram-based NDVI statistics.

🚀 How to Run

1. Clone the repository

git clone https://your-repo-url.git
cd your-repo-folder

2. Install the dependencies

pip install fastapi uvicorn pydantic shapely sentinelhub

3. Set SentinelHub Credentials

Make sure you set the correct SentinelHub credentials:

config.instance_id = 'YOUR_INSTANCE_ID'
config.sh_client_id = 'YOUR_CLIENT_ID'
config.sh_client_secret = 'YOUR_CLIENT_SECRET'

Alternatively, you can configure them through environment variables or sentinelhub.config file.

4. Run the server

uvicorn main:app --reload

The API will be available at http://127.0.0.1:8000.

📬 API Usage

Endpoint POST /ndvi

Request Body Example

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {},
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [13.822174072265625, 45.85080395917834],
            [14.5599365234375, 45.85080395917834],
            [14.5599365234375, 46.29191774991382],
            [13.822174072265625, 46.29191774991382],
            [13.822174072265625, 45.85080395917834]
          ]
        ]
      }
    }
  ]
}

Response Example

Returns a JSON containing NDVI histogram statistics for the given area over the specified time interval.

📚 Technologies Used

1. FastAPI – API Framework
2. SentinelHub-py – SDK to interact with SentinelHub APIs
3. Pydantic – Data validation
4. Shapely – GeoJSON geometry parsing

🔥 Notes

• Be aware that the SentinelHub Service Worker can rate limit you based on your subscription plan.
• The NDVI calculation uses the formula:

NDVI = (NIR - RED) / (NIR + RED)