maritime_track_tortuosity
Compute route tortuosity by comparing actual sailed distance to great-circle distance, revealing how directly a historical voyage progressed. Use to analyze navigation efficiency and detours.
Instructions
Compute route tortuosity for a single CLIWOC voyage.
Tortuosity = path_km / net_km. A value of 1.0 means perfectly direct; higher values indicate meandering. Compares actual sailed distance (sum of position-to-position haversine legs) to great-circle distance (first to last position in bbox).
Args: voyage_id: CLIWOC voyage ID (from maritime_search_tracks) lat_min: Minimum latitude for bounding box lat_max: Maximum latitude for bounding box lon_min: Minimum longitude for bounding box lon_max: Maximum longitude for bounding box min_speed_km_day: Minimum speed filter (default: 5.0) max_speed_km_day: Maximum speed filter (default: 400.0) output_mode: Response format - "json" (default) or "text"
Returns: JSON or text with path_km, net_km, tortuosity_r, inferred_direction, n_in_box
Tips for LLMs: - Use lat_min=-50, lat_max=-30 for the Roaring Forties - Tortuosity ~1.0-1.1 = direct sailing, >1.3 = detours - Compare pre/post-chronometer voyages to test navigation - Use maritime_aggregate_track_tortuosity for bulk analysis
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| voyage_id | Yes | ||
| lat_min | No | ||
| lat_max | No | ||
| lon_min | No | ||
| lon_max | No | ||
| min_speed_km_day | No | ||
| max_speed_km_day | No | ||
| output_mode | No | json |