For example, if doing a detailed survey or surveing from a vehicle, a 1 Hz (1 second) logging interval may be appropriate. If mapping, think about how often you need a data point. The logging interval will depend on the survey goals. The base receiver must have a logging interval at least as high as the rover receiver’s data from the rover can only be processed if corresponding data are collected at the base. Choose a logging interval before starting the survey. If you are starting from scratch, consider using the universal transverse mercator (UTM) coordinate system determine your zone by checking e.g.ĭata logging. Record the projection and datum used for future surveys. Note that if you are referencing a previous survey, you must use the same projection and datum that was used before. Applying a specific coordinate system during data collection of a PPK survey is not recommended, as you can apply coordinate systems during data processing. See the UNAVCO Knowledgebase for more information on antenna mounts ( ).Ĭoordinate system. If you are establishing a base marker for the first time, plan to collect at least an hour’s worth of data. For a repeatable survey, you will need a way to center and level the antenna over your mark.
Correspondingly, the antenna mount used (if any) will depend on project needs. The base GPS antenna can be set up over an existing mark or a newly established mark, or, if no repeat surveying will be needed, placed directly on the ground. No line-of-sight (visibility) is required between the base and the rover(s).īase. The base station should be located within 10 km of the area to be surveyed: the closer, the better. every 5 seconds continuous mode is used for mapping. Continuous survey mode allows ongoing data collection at a specified logging interval, e.g. Topo points are short (usually 15 second) occupations, e.g. There are two types of survey methods in PPK surveys: topo points and continuous surveys.
If you have access to raw data from a reference station already operating at an appropriate sample rate in your area (within 10 km of your survey), there is no need to set up an additional base station note that the logging rate at the base, however, must be at least as high as the desired survey rate. You may use as many rover receivers as you wish. PPK surveys require data from at least two receivers: a ’base’ (reference) receiver and a ’rover’ (moving) receiver. Data must be post-processed to achieve high-precision results this requires a processing program such as Trimble Geomatics Office. Occupation times for survey points are on the order of seconds. Post-processed kinematic (PPK) surveys are generally used for mapping or for surveying points where only several cm of precision are needed, such as 1) mapping out a feature such as a falt scarp or a shoreline 2) recording the locations of sample sites or 3) measuring the positions of markers such as stakes on a glacier to determince ice velocities.
Trimble 4700/5700/R7 - How to execute a post-processed kinematic (PPK) survey from start to finish About post-processed kinematic surveying
Trimble 4700/5700/R7 - How to execute a post-processing kinematic (PPK) survey from start to finish - Print View Trimble 4700/5700/R7 - How to execute a post-processing kinematic (PPK) survey from start to finish