Function export_hmm_emission_probabilities 

pub fn export_hmm_emission_probabilities<P: AsRef<Path>>(
    debug_info: &DebugInfo,
    output_path: P,
) -> Result<(), ProjectionError>

Export Phase 1 – HMM emission probabilities as GeoJSON

Produces a FeatureCollection with one LineString per GNSS-position × candidate netelement pair, recording the emission probability components so that the HMM observation model can be inspected spatially.

Properties per feature:

• step – GNSS position index (0-based)
• netelement_id – candidate netelement
• emission_probability – combined (distance × heading) emission probability
• distance_probability – distance component
• distance_m – absolute distance in metres
• heading_probability – heading component (omitted when unavailable)
• heading_difference_deg – absolute heading difference in degrees (omitted when unavailable)
• status – "selected", "candidate", or "rejected"