3.4.8.4. Stop and go kinematic surveying

It is known as stop-and-go technique because only the coordinates of the receiver are used when it is stationary (‘stop’ part) but the receiver continues to function while it is moving (`go’ part) from one stationary station up to the next station.

Stop and go kinematic surveying is a GNSS surveying technique that combines stationary data collection with moving observations. During the 'stop' phase, the rover receiver collects precise coordinates when it is stationary at a point. Meanwhile, during the 'go' phase, the receiver continues to record data while moving to the next point. This dual functionality allows for efficient data collection in surveying applications where many points need to be recorded quickly and effectively.

Imagine a painter who uses a measuring tape to ensure each stroke of paint is perfect. When they reach one spot (the stop), they measure precisely to ensure accuracy. However, as they move to the next spot (the go), they keep their tools ready without stopping the work. This is akin to how stop-and-go surveying allows surveyors to maximize productivity while maintaining accuracy.

The base receiver remains stationary, while the rover receiver will visit the unknown points for a very short time (< 2 min). This is the kinematic technique because the user’s receiver continues to track the satellites while in motion.

In stop and go kinematic surveying, a base receiver is established at a known location, providing a reference point for the rover receiver. The rover is moved from one point to another, where it collects data for a brief period, typically less than 2 minutes. Throughout this process, the rover continuously tracks the satellites, which ensures that accurate positional data is recorded even while in motion. This technique supports effective mapping and surveying where numerous locations need to be surveyed quickly.

Think of a food truck that stops at each vendor's market (the stationary point) to prepare a meal (collect data) before moving to the next vendor. The food truck keeps its GPS on to ensure it knows where to go next while it prepares food, thereby efficiently working without losing time due to unnecessary stops.

The software sorts out the recorded data for different points, and differentiates the kinematic or ‘go’ data (not of interest) from the static or `stop’ data (of interest). The initial ambiguity must be resolved by the software before this survey starts.

Once data is collected through stop and go kinematic surveying, specialized software processes the information to separate meaningful stationary data from the transient, mobile data recorded while moving. Before starting the survey, the software must also resolve any ambiguities about the signal, ensuring that when points are recorded, they are accurate. This step is crucial for maintaining the integrity of the collected data, particularly as it distinguishes between useful data collected during stops and non-essential data collected while in motion.

Imagine a librarian sorting through a mixed pile of books. Some books are journeys (go data) that tell stories of different locations, while others are academic texts (stop data) that provide valuable information. The librarian filters through to keep only the texts essential for research. Similarly, the surveying software extracts relevant data while discarding what is not useful.

This method is suitable for detailed surveys such as topographic mapping or boundary survey work when many points close together have to be surveyed, and the terrain poses no problems in terms of signal disruption.

The stop and go kinematic surveying method is particularly well suited for applications that require dense data collection in a short amount of time, such as creating topographic maps or surveying property boundaries. However, for this method to be effective, the terrain where the survey is conducted must allow good satellite visibility. Issues such as tall buildings, trees, or structures that may obstruct signals can pose limitations to this surveying technique.

Consider a gardener using a handheld GPS device to plot out all the flower beds in a large garden (the detailing work). The gardener moves quickly, stopping every few steps to mark a new flower bed location. However, if the garden has tall hedges (signal disruption), the gardener might find it hard to get an accurate reading and struggle to map effectively in those areas. This illustrates how the stop and go method functions best in open spaces.

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