The big antenna considerations

1. Beidou cannot 100% positioning, more don't believes indoor positioning of story-Beidou not like phone broadcast, anywhere are can received signals, many things will effect Beidou received news, contains sky star distribution State, building, viaduct, radio, leaves, grid hot paper,, will effect of things too more too more has, generally, from Beidou location up see, can see sky of area, is Beidou can received signals of area. 2. do not use one or two times, or a day or two, decides the Dipper-sky satellite state every day is different, perhaps the same place, full reception in the morning, but evening cannot be located, are possible, may also be positioning for days are in bad condition. 3. Big Dipper is good or bad, must be at the same place-a lot of people buy a new compass, will say, I use the good stuff before, but said that not correct because the time and place different, the end result is a lot of bad, must use a long time, or at the same time, to experience two different points of the compass.