Most consumer GPS receivers, including FlySight, use a ceramic patch antenna. Patch antennas are directional. That is, they attenuate any signal that isn't coming from a particular direction. This is sometimes a good thing, because it helps eliminate noise sources. However, it can also cause problems if the antenna isn't pointed in the right direction.
FlySight's antenna is pointed toward the side with the light and the label. For best results, this side should point toward the sky. For this reason, we recommend that wingsuit pilots mount the FlySight on the back of their helmet. Swoopers, who spend more time upright, may get better results by mounting the FlySight on the top of their helmet.