The whole 2 MHz slice the receiver watches, 145.02 to 147.07 MHz, five times a second. Time flows downward in the waterfall; in 3D, signal strength is height. Repeaters are marked along the bottom and light up when they transmit.
Brightness and height show dB over the band's median. Faint steady lines are often the receiver's own spurs, not stations. Drag to orbit the 3D view, pinch or scroll to zoom.