If you have a hand-held GPS device, how you hold it can affect the strength of the GPS signal. For hand-held devices, there are two type of antennas that are used: quadrifilar helix antennas, and patch antennas. Check your manual, or look on-line to determine the type of antenna that your GPS unit has.

If your GPS has a quadrifilar helix antennas, you will get the best signal when you hold your GPS unit upright so that the screen is perpendicular to the ground. If your GPS unit has a patch antenna, you will get the best signal when you hold your unit flat, so that the screen is parallel to the ground.

Holding your GPS device doesn't make a huge difference in how good the signal is. But if you are struggling to get an acceptable signal, holding it correctly based on the type of antenna you have may make the small difference that you need.