Create a new composition named Radar_background, using the NTSC D1 Square Pix, 720×540 preset, with Duration 15;00 seconds.

Drag the Sonic Loop composition to the Radar_background Timeline at time 0;00, and change the layer's Scale to 200.0, 200.0.

Duplicate the layer four times so you have five layers total.

Go to time 0;10, select all the layers, and press P. Set the layers' X Position values to 0, 180, 360, 540, 720, to distribute the layers evenly across the entire width of the composition.

Distributing the layers along the X axis

The Sonic Loop layers in formation

Stagger the layers' In points by five frames from time 0;00 to time 0;20 so they first appear at different times. For example, we set the In Point of layer 1 to 0, of layer 2 to 0;10, of layer 3 to 0;05, of layer 4 to 0;20, and of layer 5 to 15.

Select all the layers, and pre-comp (Layer > Pre-Compose) them. Name the composition radar_5across.

Duplicate the radar_5across layer four times for a total of five layers.

Select all the layers, and press P. Set the layers' Y Position values to 0, 135, 270, 405, 540, to distribute the layers evenly across the entire height of the composition.

Stagger the layers' In points by five frames from time 0;00 to time 0;20 so they first appear at different times. For example, we set the In Point of layer 1 to 0, of layer 2 to 0;10, of layer 3 to 0;05, of layer 4 to 0;20, and of layer 5 to 15.

If you preview the animation, you should see pulsing circles appear at different points in time. They fill the entire composition and continue pulsing in and out.

Close the Radar_background composition, and open the Sonic Promo composition.

Drag the Radar_background composition to the Timeline at time 0;00, and set the layer's Opacity to 25%.