# Side-Tracking Capability Considerations * The target surface should be reasonably flat: the surface should not vary more than about 10 or 15 degrees from flat. The more acoustically specular (mirror-like) the surface, the flatter it needs to be. * The DVL needs to remain pointing directly at the target surface. Exactly how directly is a function of the reflective properties of the target surface. The more acoustically specular the target surface is, the closer to perpendicular the DVL must be. * When switching between target surfaces, the Kalman filter may experience a step input / discontinuity from the sudden change of coordinate systems. It is best to ensure the ROV is not using the DVL output to control ROV position or attitude during this time. The filter will settle down within aa few seconds after a surface switch, depending on how close the DVL is to the target surface. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.ceruleansonar.com/c/dvl-75/using-other-than-the-bottom-for-the-dvl-side-tracking-capability/side-tracking-capability-considerations.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.