External GPS antenna question

Paul Fertser fercerpav at gmail.com
Sun Jul 5 19:12:13 CEST 2009


Al Johnson <openmoko at mazikeen.demon.co.uk> writes:
>> 25 * 0.5 min = 12.5 min . I assume this gives a good estimate of TTFF
>>
>> If you already have almanac (which is the usual case as almanac is
>> usually valid for months), you'll get a fix in a little more than 30
>> seconds (time required to receive ephemeris from visible sattelite).
>>
>> [1] http://gpsinformation.net/gpssignal.htm
>
> ~40s was a consistent lower limit from cold start TTFF tests made to test the 
> kernel SD drive strength and idle clock. IIRC this closely matches the cold 
> start TTFF specified for the Antaris 4.

Thanks to Daniel i now know that Antaris 4 doesn't require almanac to
start receiving ephemeris so yes, i see now how it can get FF in
~40s. Just tried it myself btw.

Sorry for confusion.

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