stack_provenance
Read-only
Check whether a site's passes are one measurement, before measuring them.
``stack_stats`` refuses a selection whose rasters were made by *different*
``umbra convert`` settings — a calibrated pass differenced against an
uncalibrated one puts the difference between two conversions on the time
axis and reports it as change on the ground. This is the question that
refusal answers, asked ahead of it: it reads each acquisition's ``UMBRA_*``
conversion record straight from its raster header (kilobytes per pass, no
pixels, no co-registration) and groups the selection by what its pixel
values *are*.
Returns ``agrees`` (whether ``stack_stats`` would accept the selection),
``groups`` largest-first — each with the conversion ``record`` its members
share, their ``item_ids`` and the ``hrefs`` to re-run on — plus ``shared``
(the record they all agree on) when they agree, ``refusal`` (verbatim the
error ``stack_stats`` would raise) when they do not, and ``unreadable`` for
any source that could not be opened at all, which is an incomplete answer
rather than a mixed one.
Reach for it in two situations. **After** a ``stack_stats`` call fails with
a provenance refusal: ``groups[0]["hrefs"]`` is the largest set of passes
that *do* agree, so re-running ``stack_stats`` on those is a measurement
rather than a guess — the refusal itself cannot name that subset. And
**before** measuring a long series you did not assemble yourself, since the
check costs a header read per pass and saves the whole cube when the answer
is no.
A series of Umbra's published products as they ship (the common case) agrees
trivially: every pass reads as ``"(unrecorded)"``, which is one value, so
``agrees`` is true and ``shared`` is empty. **No model is called.**
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| urls | Yes | ||
| asset | No | GEC |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||