PPK (Post-process kinematic), is an important GNSS positioning technology that uses carriers phase for the post-differential, it belongs to the kinematic post-process surveying technology. This surveying method requires base and rover record static data in a same time period, but they don't need to establish communication each other, so after field work, we will use raw observation data from base and rover to calculate precise and reliable coordinates.
So how does PPK work? Suppose that we are going to make a PPK survey in an effective working area, we need to setup a base at a proper place and start it to record raw observation data, meanwhile, use another gnss receiver to work as rover, and let it synchronously record raw observation data at the same time period with base during collecting points. Due to the strong spatial relativity on satellite clock errors or the other errors between base and rover, we will use gnss post-process software to calculate data after field work. The data will be linear combined and generate a virtual carriers phase observation value, then spatial relative position between base and rover will be calculated, after that, input known coordinate for base in software, we will get the rover precise coordinate. For PPK base, it can also be a CORS station too, as long as rover works in working range of CORS station.
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| PPK survey and data processing |
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we take SOUTH X5 handheld controller for example to make a PPK job. First of all, we setup SOUTH Galaxy G1 for base and start to record raw observation data.
Switch on X5 handheld controller and run GIStar program, create a new project and setup coordinate system. |
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| Go to settings--General setting--Post-Differential, enter this interface to set file name, antenna height and collection interval(in second), enable PPK function and click "start to record static file" button to start the raw observation data recording. |
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| Return to main interface and go to Task--Pt Survey, click point collection button to collect a point while achieve conditions. Please notice that rover should stay on the point for the collection interval finish so that software should record PPK data completely. Collect the other points with same way. |
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| When the collection is finished, go to Post-Differential interface to disable PPK function, and stop recording raw observation data. |
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Download raw observation data file(**.sth)from base, and download data files from X5 rover, including raw observation data file(**.sth), PPK file(**.ppk) and coordinate system file(**.sys)
sth file and ppk file: SD card-->com_southgnss_gistar-->ProjectData-->(project name)-->Data
sys file: com_southgnss_gistar-->ProjectData-->(project name) |
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| Run SOUTH SGO software on computer and then import raw observation data file from base and rover. If the rover raw data file display as static in data type, please change data type to be Dynamic for rover raw data, otherwise the software will calculate all files as static, not ppk. |
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| Next is to import ppk file and coordinate system file to pair with raw data from rover. |
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| Set base station data as control point and input known coordinate, click process kinematic button to start processing data. |
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| After that click Dynamic route processed report |
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| Note: The default settings of report will output different solution result for each point, you can select just output fixed solution in Project Setup… |
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