r3 - 22 Sep 2009 - 18:57:05 - DagobertoSalazarYou are here: TWiki >  Documentation Web  >  AskedQuestions > NonIntegerMeasurementEpochs

Question

Hi,

I have phase and pseudorange measurements that are made at times that are as much as 32 millisec different than the integer second (and successive measurements drift). The mfg. has decided to not adjust their lock until it has drifted that much. They specify their time to about 100ns, thus the 7 decimal places on the time.

Is there a way within GPStk to adjust the measurements to the nearest seconcds? If not, what is the right way to correct these data?

Thanks, Sridhar

Here are 2 measurements:

09 09 09 20 00 0.0235102 0 7G07G08G11G15G17G19G28

09 09 09 20 00 1.0155106 0 7G07G08G11G15G17G19G28

-- SridharAnandakrishnan - 20 Sep 2009

Answer

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Hi, After delving a little deeper into this, I see that there is a Synchronize object with a default tolerance of 1s. This appears to allow 2 data streams to be associated correctly even if their exact times are different.

If I have this wrong, please let me know... otherwise, thanks for a great resource.

S

-- SridharAnandakrishnan - 21 Sep 2009

Hi Sridhar!

In order to know more about "Synchronize" object, take a look at examples implementing DGPS: "example7.cpp" and "example10.cpp".

Also, you may want take a look at the GNSS Data Structure (GDS) called "gnssDataMap". It is intended to deal with multi-source, multi-epoch data streams.

Best regards,

Dago

-- DagobertoSalazar - 22 Sep 2009

 
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