GROUND_TRUTH_BRAINSTORM.md

Ground Truth: Approach

Map approach: D3 choropleth with TopoJSON (CHOSEN)

• CDN: world-atlas@2/countries-110m.json + topojson-client@3
• d3.geoNaturalEarth1() projection
• Integrated two-panel layout: map left, radar right
• Hover on country → radar shows that region

Alternative rejected: Leaflet/Mapbox

Over-engineered for this use case. D3 native geo is sufficient.

Radar refactor approach

Expose window.drawGeoRadarChart(containerId, geoData, options) from geo-radar.js. geo-map.js calls it to update the side panel. Keep backward compat with scrollama onStep.

Bubble fix

Simple constant change — BUBBLE_RADIUS_RANGE and TOP_N. No architectural change.