What makes Empress Augusta Bay a radar battle?

Calling Empress Augusta Bay the first radar battle depends on the definition. Blackett Strait had already demonstrated radar-directed combat, but three cruisers and three destroyers ambushed only two destroyers. At Matapan, radar helped locate the enemy before a close-range action shaped by established British night-fighting doctrine. Empress Augusta Bay provides an example of an American force directing its fire almost entirely by radar against an opponent relying on visual methods. North Cape is another comparison, characterized as an even more pronounced ambush. Equipment and doctrine entered service piecemeal, so individual ships could demonstrate a technique before an entire formation adopted it.