PPMAP implementation uncertainty audit

PPMAP implementation uncertainty audit

Human-requested continued research, 11 October 2026. The documentation now identifies the maintained source repository at https://github.com/ahoward-cf/ppmap. Directory names/installation guidance were inspected, but uncertainty source contents have not been read for this unit. Freeze these rules before that readout.

Question: does the maintained or included legacy implementation provide a source-traceable route to integrated-column uncertainty, and can it be bound to our archived Hi-GAL products sufficiently to justify a new validation protocol? This is distinct from the finished cached-product audit. The 333/800 gate and all requested identities remain unchanged; no MIR source rows may be read.

  1. Fetch the current master commit and recursive file-tree metadata from the documented GitHub repository, then pin that exact commit for every content request. Do not clone or install anything. Select relevant source files from the actual tree; retain current/legacy roles and complete source hashes.
  2. Trace the uncertainty calculation, any integrated-error/covariance output, prior/normalisation units and the relationship to published equations 15–17. Use bounded reads of complete saved files with line citations. Do not execute third-party code, simulate new maps or download observations/PSFs.
  3. Independently verify cited statements against the frozen complete bytes. State whether errors derive from a diagonal approximation, full inverse, covariance propagation or another formula; do not infer a formula by filename.
  4. Establish release binding if possible from explicit source/version/product evidence. Similar variable names and ETA=10 do not prove the 2017/2018 archive used the currently inspected implementation. If that binding is absent, report the implementation result separately and leave real-clump covariance unknown.

Positive outcome: a traceable, release-bound integrated-error route motivates a separately registered validation, not immediate relaxation of the primary gate. Negative/insufficient outcome: missing covariance or missing release binding ends this unit with exact requirements for progress. Source retrieval, byte counts and successful hashes are not scientific findings. Preserve earlier negative results.

Acquisition: <=20 HTTPS GET requests total to api.github.com and raw.githubusercontent.com for this single repository; <=256 KiB per response, <=512 KiB response bodies cumulatively; <=30 seconds per request, no redirects or automatic retries. Stop on a failed/truncated response or limit exhaustion; preserve its journal. No full Git history, archives, Git LFS or binary products. Resource limits: <=10 minutes, <=2 MiB outputs including source copies and journals, <=256 MiB monitored worker RSS, one numerical thread, lowered priority and >=5 GiB free disk. Use the live guard and preserve its receipt. Commit this protocol and bounded fetcher before readout; snapshot verified findings separately.

Primary context: https://ppmap.readthedocs.io/en/latest/installation.html and https://arxiv.org/html/1509.08699v1, equations 15–17. No private Atlas/E155/E121 action or archived generic-star experiment is authorized by this unit.