# Precise Post Processing (PPP)

GNSS modules can be configured to continuously stream data in raw data format for PPP purposes. The data is initially recorded via u-center with the below configuration messages. Then the file can be used for post-processing with the help of RTKLib. 

![](https://3825805345-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LYSZeu4HjB-NrVI4riL%2Fuploads%2Fjg33n69QFCQXH9y0wqdC%2Fucenter_record_button2.png?alt=media\&token=a90affc2-6f68-4e34-b1d6-ee17438a88fc)

For raw data recording, you may activate the following messages to obtain .ubx data:

![](https://3825805345-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LYSZeu4HjB-NrVI4riL%2Fuploads%2Fb1sA86YV2aub9essgMb7%2Fucenter%20MSG%20display.png?alt=media\&token=29f977d8-f593-43a0-b655-937d451ec09f)

* UBX to USB
* UBX to UART (We prefer using UART1, whilst UART2 is not viable for raw data processing)

Menu -> View → Configuration View → MSG (Messages):\
1\. Select Message “02-10 RXM-RAW”, and check USB. \
Then click on the “Send” button at the bottom left of the Messages window.\
\
2\. Select Message “02-11 RXM-SFRB”, and check USB. \
Then click on the “Send” button at the bottom left of the Messages window.\
\
3\. Select Message “02-30 RXM-ALM” and check USB. \
Then click on the “Send” button at the bottom left of the Messages window.\
\
4\. Select Message “02-31 RXM-EPH” and check USB. \
Then click on the “Send” button at the bottom left of the Messages window.

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Finally, Menu -> View → Configuration View → CFG (Configuration): Save to current configuration, Select all devices.\
Then click on the “Send” button at the bottom left of the Configuration window.