neomutant Posted December 12, 2012 at 04:08 PM Share Posted December 12, 2012 at 04:08 PM http://en.wikipedia.org/wiki/Differential_GPS Idea is to make one Stack "A" (Masterbrick+Gps+WiFiExt Used as static ground base station where exact 3Dposition is known) comunicate with another stack "B"(Masterbrick+Gps+WiFiExt on moving object) Stack "A" have known GpsPosition and read Gps position and subtract it with Known position = "correction vector" then sending differential correction information to Stack B GPS using WI-FiExt."Correction vector" Will change over time. it's possible to get this way around a centimeter precision GPS. Can Brick Creators/Masters make it native in firmware? Why GPS is not accurate: quote from wiki: When GPS was first being put into service, the US military was concerned about the possibility of enemy forces using the globally available GPS signals to guide their own weapon systems. Originally, the government thought the "coarse acquisition" (C/A) signal would only give about 100 meter accuracy, but with improved receiver designs, the actual accuracy was 20 to 30 meters. Starting in March 1990, to avoid providing such unexpected accuracy, the C/A signal transmitted on the L1 frequency (1575.42 MHz) was deliberately degraded by offsetting its clock signal by a random amount, equivalent to about 100 meters of distance. This technique, known as "Selective Availability", or SA for short, seriously degraded the usefulness of the GPS signal for non-military users. //Edit: Information about "SA" is outdated At what time was SA turned off? Selective Availability ended a few minutes past midnight EDT after the end of May 1, 2000. The change occurred simultaneously across the entire satellite constellation. http://www.gps.gov/systems/gps/modernization/sa/faq/#time DGPS can solve this problem Kris. Quote Link to comment Share on other sites More sharing options...
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