The rainbow in the above simulation is due to light enter raindrop/waterdrop , refracted twice and reflected once or twice.
The angle of the rainbow is nearly 42 degree. And the rainbow is always at the same relative position no matter how you move. You can not pass it. Because see rainbow from different raindrop when you move.
However, there are several way to produce rainbow light pattern. e.g. light pass through a prism, the image in the URL you have provided, ...etc.
May I know what is the direction of the sun when you saw the rainbow? Is there any other strong light source around?