Split Points, Timing Points, and Timing Devices
To calculate a participant's result, it is necessary to know the participant's start and finish times. If the times for a participant passing through each intermediate point are known, the participant's gun time and chip time for each intermediate point can be calculated.
1. Splits and Split Points
Real running events may involve complex tracks, such as loop tracks, out-and-back tracks, or other special cases. Regardless of whether the track involves loops or out-and-back sections, the course for a contest can be divided into consecutive splits, connected end-to-end, and each split can be abstracted as a straight segment. As shown in Figures 2.1 and 2.2.
Figure 2.1: A certain marathon event course
Figure 2.2: Typical split points of a certain marathon event
The concept of split points corresponds to the concept of splits. For a split, the finish line of the split represents the split itself. For example, a 5KM to 10KM split can be simplified as the 10KM split, and the finish line of this split is the 10KM split point. Conversely, the 10KM split refers to the split from 5KM to 10KM split, and the 10KM split point represents the 10KM split.
The start split refers to the split from the point where the participant is positioned at the start line (at the time of the starting gun) to the start line itself. If an event has 11 split points, including both the start and finish lines, then there are 11 splits, with the first split being the start split. The start split's start time is the gun start time, and the finish time (arrival time) for the start split is the start time, with the duration for the start split being the time used before start.
The key to the timing problem, when the gun start time of a participant is known, is to obtain the participant's time at each split point, including both the start and finish lines.
2. Timing Points
A timing point is a location where timing device is placed. When a participant carrying a timing chip passes through this timing point, the chip will transmit data. Timing point and split point are two completely different concepts. Each split point corresponds to a timing point, but one timing point can correspond to multiple split points. By separating the timing point and split point, it becomes easy to describe courses with loops or return segments. This is illustrated by the following two examples.
Example 1: In the following event course, participants start from the starting line, pass TP1, then TP2, run back to TP1, and finally reach the finish line. The two split points at TP1 are geographically the same location, but they are drawn separately in the diagram to show that there are two split points here. After completing one loop, the course and timing points at the finish line are shown in Figure 2.3.
Figure 2.3: An event course and timing points
Figure 2.4: Split points and timing points after completing one loop
If the course specifies that the participant must complete two loops before reaching the finish line, the split points and timing points are shown in Figure 2.5.
Figure 2.5: Split points and timing points after completing two loops
Example 2: In a certain marathon event, the course is shown in Figure 2.6. The 5KM and 15KM split points share a timing point, and the start and finish lines share a timing point. The split points and timing points are shown in Figure 2.7.
Figure 2.6: Map of a marathon course and the distribution of timing points
Figure 2.7: Split points and timing points of a certain marathon
3. Timing Devices
The timing device is a specific apparatus used to detect the participant's passing time. Through the tag worn by the participant, the timing device detects when a participant passes by and records the exact timestamp at that moment, thereby completing a data record. A raw data entry primarily consists of the participant's chip code and the corresponding timestamp.
A timing point may have multiple timing devices, which serve as backups or are necessary due to insufficient track width, requiring additional width. Therefore, a split point corresponds to a timing point, and a timing point includes one or more timing devices; each timing device belongs to a specific timing point, and a timing point corresponds to one or more split points.
