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Discovering an orphaned remote-sensing copy creates an immediate version question: can it still influence a decision, feed a derivative or be cited as current? Containment blocks unsafe use while preserving provenance. User-version attestation then records which source and replacement a person or system actually holds, not merely that a notice was sent. A debt ledger retires only when its defined population is resolved and the residual discovery boundary is explicit.
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Chapter contents
Choose the route closest to the decision, or read from Chapter 1. The chapters remain open; these grouped routes are a navigable index.
Route 1 · Define the decision
Route 2 · Work the ledgers
Route 3 · Transfer the method
Route 4 · Check limits and evidence
Route 5 · Ask and continue
CHAPTER 1 OF 12 · DEFINE THE DECISION
1. Classify the orphan before acting
Identify the file, source product, processing date, checksum, location, owner, current use, downstream dependencies and consequence. An orphan is outside the known governance graph, not necessarily an invalid product.
Distinguish historical copies, live operational inputs, reproducibility packages and abandoned exports. Their containment and preservation needs differ.
CHAPTER 2 OF 12 · DEFINE THE DECISION
2. Contain use without erasing evidence
For high-consequence use, disable scheduled jobs, remove the asset from current selectors, quarantine write paths and point users to the replacement. Preserve a read-only copy, manifest and discovery record when historical interpretation requires it.
Containment should be reversible long enough to investigate. Immediate deletion can destroy the evidence needed to find derivatives and explain past decisions.
CHAPTER 3 OF 12 · WORK THE LEDGERS
3. Build an orphan-containment register
A flood-response review finds four local products derived from a reprocessed Landsat scene.
| Copy | Current role | Version evidence | Containment | Disposition |
|---|---|---|---|---|
| Emergency map | Drill input | Old product identifier | Quarantine and replace | Rerun |
| Research notebook | Reproducibility | Pinned old checksum | Read-only label | Preserve |
| Public dashboard tile | Live display | Unknown build manifest | Disable layer | Rebuild |
| Training slide | Historical example | Date visible | Add superseded label | Retain |
| Batch script cache | Scheduled dependency | Old path confirmed | Stop job | Purge after audit |
The emergency map, dashboard and batch cache are blocked first. The notebook and training slide remain available under explicit historical status.
CHAPTER 4 OF 12 · WORK THE LEDGERS
4. Work a user-version attestation decision
Each high-consequence owner must attest what is held and what action was completed.
| Attestation field | Required evidence | Owner response | Result | Next action |
|---|---|---|---|---|
| Source identifier | Product ID or checksum | Old ID supplied | Affected | Replace |
| Local derivatives | Named file list | Two exports listed | Incomplete | Search shared folder |
| Replacement installed | New checksum | Matches manifest | Pass | Test workflow |
| Decision comparison | Rerun result | One zone changes | Material | Notify users |
| Old route disabled | Job or selector evidence | Scheduler off | Pass | Monitor logs |
The changed zone keeps the case in the debt ledger until affected decisions are reviewed, even though the replacement is installed.
CHAPTER 5 OF 12 · WORK THE LEDGERS
5. Design attestations for people and systems
Ask for source identifier, storage location, derivatives, replacement state, decision sensitivity and disabled routes. Automated systems can attest through inventories, checksums, manifests and execution logs.
Use consequence-based deadlines and escalation. Low-risk historical copies may need labels; live emergency workflows need immediate verified replacement.
CHAPTER 6 OF 12 · TRANSFER THE METHOD
6. Retire the debt ledger with a boundary statement
Close every known high-consequence item, resolve or accept lower-consequence items, verify owners and preserve exceptions. Then state which systems, repositories and user groups were covered and which could not be searched.
Retirement freezes the ledger as a historical record. A standing discovery trigger opens a new linked event if another orphan later appears; it does not quietly edit the retired totals.
CHAPTER 7 OF 12 · TRANSFER THE METHOD
7. Changed-context transfer: wildfire field packages
Transfer the method to offline wildfire-recovery packages on field tablets. Connectivity gaps mean central catalogue updates cannot replace local layers automatically.
Device checksums identify two old packages. Operational layers are quarantined and regenerated; a historical briefing stays read-only. Attestations include the replacement checksum and workflow test before the debt ledger retires for the inventoried fleet.
CHAPTER 8 OF 12 · TRANSFER THE METHOD
8. Connect discovery, closure and version propagation
Start with debt-burn-down verification and orphaned-copy discovery. Use amendment closure and user acknowledgement for the earlier closure decision.
Return to amendment propagation and citation-version governance when the orphan feeds published derivatives or historical reports.
CHAPTER 9 OF 12 · CHECK LIMITS AND EVIDENCE
9. Limits and common misconceptions
Attestation is not proof merely because a user signs it; the fields and supporting evidence must be checkable. A retired ledger does not prove that no unknown copy exists outside the declared discovery boundary.
Deletion is not the only safe disposition. Historical reproducibility may require preserved superseded data with clear status. Conversely, a visible superseded label is insufficient for an asset still feeding an operational pipeline.
CHAPTER 10 OF 12 · CHECK LIMITS AND EVIDENCE
10. Practical evidence and retirement checks
Archive the orphan identifier, checksum, source version, discovery path, owner, role, dependencies, consequence, containment, replacement, decision comparison, notifications and preserved historical copy.
For attestation and ledger retirement, retain the question set, evidence attachments, nonresponders, escalation, resolved and accepted items, search coverage, inaccessible systems, closure authority, retirement date and future discovery trigger.
CHAPTER 11 OF 12 · ASK AND CONTINUE
11. Frequently asked questions
Is a sent notice a version attestation?
No. Attestation records what the user or system holds and the action completed, supported by identifiers or other evidence.
Must every old copy be deleted?
No. Preserve justified historical copies under controlled status, but remove live operational pathways to superseded versions.
Can a retired ledger reopen?
A later discovery should create a linked new event or ledger under the standing trigger, preserving the integrity of the retired record.
CHAPTER 12 OF 12 · ASK AND CONTINUE
12. Sources and next reading
USGS’s Landsat Reprocessing: How to Keep Your Data Current guide, dated 6 January 2026 explains how users can compare local product lists with current metadata. The Landsat Collection 2 page recommends considering replacement of reprocessed data and derived products, and the 28 January 2026 USGS update explains that affected product levels are regenerated. The registers and wildfire case are original.
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