gps-denied-onboard/_docs/02_document/common-helpers/01_helper_geo_geometry.md

Geo Geometry Helper

Purpose

Shared geospatial and camera-geometry utilities used by camera ingest, safety wrapper, cache lifecycle, anchor verification, and validation.

Responsibilities

• WGS84 to local tangent plane conversions.
• Haversine/ground-distance calculations.
• Ground sampling distance calculations.
• Camera footprint projection from intrinsics, extrinsics, altitude, and attitude.
• Homography and covariance unit conversions for reporting.

Non-Responsibilities

• No image matching.
• No state estimation.
• No MAVLink emission.
• No cache policy decisions.

Consumers

Component	Usage
Camera ingest/calibration	Footprint and calibration sanity checks
Safety/anchor wrapper	Distance/covariance/unit conversion
Anchor verification	Pixel-to-ground error reporting
Cache/tile lifecycle	Tile footprint metadata
Validation harness	Error thresholds and reports