> For the complete documentation index, see [llms.txt](https://docs.tryterra.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tryterra.co/faq/help-topics/something-else/provider-data-fields-and-coverage/no-derived-metrics-from-samples.md).

# Can speed be computed from position samples?

Payloads reflect the **raw data each provider supplies**. Terra does not compute non-trivial derived metrics like speed from position samples, which keeps data consistent and lets you apply your own calculation methods.

If a provider omits speed samples:

* **Derive speed client-side** from the position samples.
* Raise the missing source data with the provider.

See the [data models](https://docs.tryterra.co/reference/health-and-fitness-api/data-models) and [samples](https://docs.tryterra.co/reference/health-and-fitness-api/samples) reference for what each payload contains.