[time-nuts] Correcting jitter on the 1 PPS signal from a GPSreceiver.
Bob Camp
kb8tq at n1k.org
Sat Sep 13 22:15:08 UTC 2014
Hi
When you read back the survey location do they make sense? If the antennas are X m apart on at an angle of Y, how close do the locations agree with this? Often the survey process is not adequate to ensure a good fix with this or that antenna.
Bob
On Sep 13, 2014, at 5:00 PM, Peter Reilley <peter at reilley.com> wrote:
> Yes, both have completed their surveys. During the survey process
> I was getting up to 150 uS of error between the PPS pulses.
>
> Pete.
>
>
> -----Original Message-----
> From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Bob Camp
> Sent: Saturday, September 13, 2014 4:33 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Correcting jitter on the 1 PPS signal from a
> GPSreceiver.
>
> Hi
>
> Have they both completed a survey and does the survey make sense?
>
> Bob
>
> On Sep 13, 2014, at 10:41 AM, Peter Reilley <peter at reilley.com> wrote:
>
>> I have 2 Trimble Resolution T receivers and I have compared the 1 PPS
> signal
>> between the 2 units. They are spec'ed at 15 nS accuracy. I am seeing
>> about
>> 80 nS of jitter between the two. This is with about 6 satellites in
> view.
>>
>> I was thinking about ways to improve this. Since this is a stationary
>> installation,
>> can you use the jitter in the reported location (latitude and
>> longitude) to correct for the 1 PPS jitter?
>>
>> The location data is derived using the internal GPS disciplined
>> oscillator so both
>> pieces of information should show the same jitter error. If you compare
>> the reported
>> location with the known fixed location you should be able to use that
>> error to correct for the 1 PPS error.
>>
>> Does this make sense or am I missing something?
>>
>> Pete.
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
More information about the Time-nuts_lists.febo.com
mailing list