How to validate DAS metadata in JSON

This notebook demonstrates a workflow for accessing and validating Distributed Acoustic Sensing (DAS) metadata. 

Steps covered:

1. Environment Setup: Installation of boto3 (for S3 access) and jsonschema (for data validation);
2. S3 Data Retrieval: Configures a boto3 client to access a public S3 endpoint (GFZ Potsdam) using unsigned requests. It downloads a metadata file named 3u2023.json
3. Schema Fetching: Uses the requests library to fetch the official FDSN DAS-Metadata JSON schema (v2.0) from GitHub;
4. Validation:
   • Initial validation of the downloaded metadata against the schema to ensure compliance.
   • A demonstration of how schema validation works by intentionally introducing a type error (changing an array to a string) and showing the resulting ValidationError