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.[2] Starting in March 1990,[3] 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//Edit: Information about "SA" is outdated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.

Very interesting idea, but what I dont understand how you will get a very precise position for stack A at first ?

And that brings me to a next general question to TF guys about the coming soon GPS-Bricklet if it will accept and receive data from Galileo and/or Glonass System and combine it with Navstar ?

Very interesting idea, but what I dont understand how you will get a very precise position for stack A at first ?

 

This is question to "LIS expert" (ang. Land Information System) they know how to do it very precise. I will ask my frend he is LIS Expert/Map Creator.

 

I would do it by averaged data from the GPS position for period of time (like 30 min). and somehow transfer it to MasterBrick which controlling DGPS.

But would you have to implement this on the Brick? Wouldn't it be a lot easier to implement this on the PC, that has all of the information from both GPS Bricklets?

both GPS units must be reading position synchronously to make DGPS possible.

 

I Dont know it will be possible synchronize them programmatically at my end. "And if" maintaining the same reading rate.

 

the second thing is an investment in the additional modules transceiver transmits GPS corrections.