Final answer:
A wandering baseline artifact in recorded signal data can be identified by fluctuations that are unrelated to the actual signal of interest. In surveying contexts, the baseline is a fixed line used to measure parallax, and in archaeology, it assists in systematically documenting cultural artifacts.
Step-by-step explanation:
Identifying a Wandering Baseline Artifact
A wandering baseline artifact can be identified in various types of signal readings, such as in electrocardiograms (ECGs). These artifacts are characterized by fluctuations in the baseline of the recorded signal that are not due to the actual signal of interest (for instance, the electrical activity of the heart), but are instead caused by extraneous factors such as patient movement, loose electrodes, or poor contact. In the context of surveying, however, the concept of a baseline refers to a fixed reference line between two points, such as line AB in Figure 19.4 from the question. Notably, this type of baseline is used in conjunction with observations from multiple points to take advantage of parallax to determine the distance to a remote object, such as a tree across a river. In archaeological surveying, as described above, a baseline may also refer to spatial reference lines used to coordinate the systematic documentation and discovery of cultural artifacts or structures.