What is rio in top gun?

Rio is the code name for the Radar Intercept Officer played by actor Anthony Edwards in the movie Top Gun. He is the back-seater and navigator in the fighter jets flown by the main character, Maverick (played by Tom Cruise), and his wingman, Goose (played by Anthony Edwards). Rio helps to scan the skies for enemy aircraft and provides critical information to the pilots during dogfights. He also serves as a friend and confidante to Goose and helps him deal with some personal struggles throughout the movie.