Post-Processing Kinematic (PPK) is a high-precision GNSS positioning technique that achieves centimeter-level accuracy by combining rover observations with reference station data after field collection, rather than in real-time. PPK applies the same carrier phase processing and ambiguity resolution algorithms used in Real-Time Kinematic (RTK), but performs these calculations during post-mission processing when complete data from both rover and base station are available for analysis.
The PPK workflow involves collecting raw GNSS observations on the rover during field operations, simultaneously recording observations at a reference station (or arranging to obtain data from a public CORS network), then combining these datasets in desktop software after returning from the field. This approach eliminates the real-time communication link between base and rover that RTK requires, removing infrastructure complexity and potential connectivity failures as operational concerns.
Several characteristics make PPK advantageous for specific applications. Reliability improves because data can be processed multiple times with different parameters or reference stations to verify results. Efficiency increases because rovers operate independently without waiting for correction signals or managing radio/cellular connectivity. Coverage extends to areas without real-time correction infrastructure, provided post-processed reference data is available. Accuracy may actually exceed RTK in some scenarios because post-processing algorithms can use data from both before and after each epoch, enabling more robust ambiguity resolution.
PPK is widely used in surveying, mapping, and aerial/drone applications where real-time positioning is not essential. UAV photogrammetry commonly employs PPK to georeference imagery without requiring onboard RTK radios and antennas. Cadastral surveys may use PPK for office processing of field observations. Geophysical surveys record raw data for later precision processing. The tradeoff is delayed results, users must wait until post-processing to confirm achieved accuracy, making PPK unsuitable for applications requiring immediate centimeter-level feedback like machine guidance or autonomous navigation.
