# Post processing base station observations

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If your base station was placed over a known point during collection of GCPs, you can skip this step. This section is intended for users who collect GCPs while their base station is streaming corrections from an averaged or current position, as well as users who collect raw base station observations during a LiDAR aquisition.
{% endhint %}

Post processing raw observations from your base station through services such as OPUS or CenterPoint RTX can significantly improve the accuracy of your base station's poisiton, and thus improve the accuracy of all associated GCPs. 

To get started, connect your base station to your computer using the included 7-pin LEMO to USB cable and turn the receiver on. Once your computer registers the receiver as a storage drive, navigate to the receiver's *record* folder. This folder will contain DAT files recorded by your receiver. 

![DAT files stored on the S900 receiver](https://content.gitbook.com/content/dEevfLZRIk38LUPwDa4V/blobs/YE64mhGgERt9uniMz2Sj/Capture.JPG)

DAT files need to be converted to RINEX before they can be processed by OPUS or CenterPoint RTX. Download the conversion software [here](https://storage.phoenixlidar.com/software/StaticToRinex_20191018.rar). 

![](https://content.gitbook.com/content/dEevfLZRIk38LUPwDa4V/blobs/qPkGrIpLvNUZubDLCnk2/Capture3.JPG)

It is recommended to convert to RINEX version 2.10. Once your settings are configured correctly, click Export and StaticToRinex will generate several files in the same directory where your DAT file is located.

![RINEX files generated by StaticToRinex software](https://content.gitbook.com/content/dEevfLZRIk38LUPwDa4V/blobs/iC0GXlLDFiaSjDnAVOe0/Captur33e.JPG)

Upload the observation file, ending in *\_MO.rnx,* to OPUS or CenterPoint RTX for processing. Click [here](https://geodesy.noaa.gov/OPUS/about.jsp) for information on how to use NOAA's OPUS, the Online Positioning User Service.