What factors affect the handheld GPS receive signal?
The hand-held GPS is generally accepted the satellite signal, a sheltered place will affect the signal delivery in different range of handset with method, sometimes, because of the incorrect operation, the human body is one of the obstacles
In addition to not see the sky (such as indoor, underground, dense forest) and narrow alleys and tall buildings on both sides of the environment, there will be no impact. Many GPS has 12 receivers (antenna unit), as long as it can capture 3 satellites can be three-dimensional positioning (including height), the 2 satellites can be flat positioning.
Active ionosphere, large canopy, high voltage wire, high building.... Have influence.
The United States Department of defense. A SA satellite signal to interference (the U.S. government for consideration of security of civil code of a called "selective availability (Selective SA Availability)" interference, to ensure the best protection system is effective. Because of the random error information added by SA in the navigation message, the positioning accuracy of the civil signal C/A code is reduced to about 100 meters. However, the use of differential GPS technology, the system error can be reduced to 10 to 15 metersTwo. Weather factors (including sunspots, bad weather, etc.) to reduce the intensity of the received signalThree. In buildings, vehicles, insulation paper, or metal shielding, GPS signal will be reduced or completely lost signal. In open spaces, GPS devices receive the best signal. .
