Increasing GPS accuracy with EGNOS

Christian christian at
Mon Oct 5 17:41:33 CEST 2009

Al Johnson schrieb:
> On Sunday 04 October 2009, Erik Lundin wrote:
>> Good news, indeed. Does the Neo FreeRunner support EGNOS signals? Both
>> the hardware and software?
> According to this the Antaris 4 is capable of using WAAS, EGNOS and MSAS, 
> collectively known as SBAS, and the signal is received through the GPS 
> antenna. By default it is enabled, with one search channel, although this can 
> be configured through the ubx protocol. The status can also be shown in ubx 
> messages. This is probably worth checking to see what is actually happening 
> when in Europe, as when it was written EGNOS was in test mode, and its use was 
> disabled by default. It is unclear whether this was because of a 'test mode' 
> flag in the signal or hardcoding in the firmware.

I found this in the source of ogpsd on my Freerunner:

def initializeDevice( self ):

    # Use high sensitivity mode

    #self.send("CFG-RXM", 2, {"gps_mode" : 2, "lp_mode" : 0})

    # Enable use of SBAS (even in testmode)

    self.send("CFG-SBAS", 8, {"mode" : 1, "usage" : 7, "maxsbas" : 3,
"scanmode" : 0})

So it seems that SBAS has always been enabled even in test mode. Does
anybody know where we can get information if sbas is really active and
used by the chip?


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