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Spectral Libraries

What this feature is for​

Spectral libraries help you organize and reuse spectral signatures.

The simplest way to think about the feature is:

  • a signature is the thing you care about
  • a library is where signatures are grouped and stored

That is all most users need.

Start with the signature​

Each signature represents something you want to identify, compare, or use in a model.

What matters most about a signature is:

  • what it represents
  • where it came from
  • which sensor collected it
  • when it was collected
  • where it was collected
  • any notes or metadata that help explain it

Libraries exist to help you organize signatures. They are not more important than the signatures themselves.

What a library is​

A library is a container of signatures.

You can use libraries in different ways:

  • as a private experiment library
  • as a project library to share with teammates
  • as a published curated library for long-term reuse

This flexibility is intentional. You do not need a separate concept for experiments.

When to create a library​

Create a library when:

  • you want a place to upload and work with signatures
  • you want to group signatures for a specific use case
  • you want to share a working set with a teammate
  • you want to maintain a curated reusable set over time

Examples:

  • PRISMA_LANDFILLS
  • PRISMA_NEW_DELHI
  • Oil Spill Candidates
  • Published PRISMA Library

Visibility states​

Libraries can move through different visibility states as your work evolves.

Private​

Private is the best default for new work.

Use a private library when:

  • you are experimenting
  • you are uploading new signatures
  • the library is not ready to share

Private libraries help prevent the shared list from becoming cluttered.

Project​

Use a project library when:

  • the library should be visible to teammates in a project
  • you want to point others to the exact same working set
  • the library is useful, but not yet ready to be broadly reused

Published​

Use a published library when:

  • the signatures are curated
  • the library is meant for long-term reuse
  • others should be able to discover and rely on it

Archived​

Archive a library when:

  • the experiment is over
  • the library has been replaced by something better
  • you want to keep it for reference without leaving it in the active list

Default workflow​

  1. Create a new library
  2. The library starts as Private
  3. Upload or create signatures in that library
  4. Use the library for your experiment or task
  5. If you want to share it, move it to Project
  6. If it becomes a durable reusable asset, promote good signatures into a curated Published library
  7. Archive older working libraries when they are no longer active

This lets you move quickly without having to organize everything perfectly from the start.

Example: target detection experiment​

Imagine you want to train or test a target detection model.

You:

  • upload 5 signatures
  • test them
  • decide 2 are poor candidates
  • upload a few more
  • want to share the set with a teammate
  1. Create a Private library for the experiment
  2. Upload the 5 signatures into that library
  3. Test and evaluate them
  4. Remove the poor candidates from that experiment library if they are no longer useful there
  5. Add better candidates as you find them
  6. Move the library to Project if you want teammates to use the same set
  7. If some signatures prove useful long-term, copy or move them into a curated Published library

This keeps experimentation simple and sharing easy.

Example: many PRISMA libraries over time​

You may naturally create libraries like:

  • PRISMA_LANDFILLS
  • PRISMA_NEW_DELHI
  • PRISMA_BAKERSFIELD_OIL_AND_GAS

That is okay. It reflects real working use cases.

The cleanup happens later.

  1. Keep those libraries private or project-scoped while they are active
  2. Identify the signatures that turned out to be good long-term candidates
  3. Move or copy those signatures into a curated published PRISMA library
  4. Add useful metadata to each signature, such as:
    • location
    • theme like landfill
    • sensor
    • date
  5. Archive the older temporary libraries if they are no longer needed

This gives you both freedom and structure:

  • freedom while experimenting
  • structure when you are ready to curate

How to keep your library list tidy​

These habits help a lot:

  • create new libraries as Private
  • use Project only when you want others to see the library
  • publish only curated libraries that are worth reusing
  • archive old experiments
  • improve signature metadata over time

The goal is not to avoid creating libraries.

The goal is to avoid leaving every temporary library active forever.

Naming guidance​

Users often create libraries around use cases. That is fine.

But over time, library names can become overloaded with:

  • sensor
  • place
  • theme
  • date
  • processing stage

Try not to rely only on the name to explain everything.

As a library becomes important long-term, improve the metadata on the signatures inside it. That makes the signatures easier to find and understand later.

A simple rule of thumb​

If you are asking:

  • “Where should I put these signatures while I work on them?”

Create a Private library.

If you are asking:

  • “How do I share this signature set with teammates?”

Move the library to Project.

If you are asking:

  • “How do I keep the good signatures for long-term reuse?”

Move or copy them into a curated Published library.

FAQ​

Should every new library be published?​

No.

Most new libraries should start as Private.

What should I do with an old experiment library?​

Archive it if it is no longer active.

What should I do with signatures that proved useful?​

Move or copy them into a curated Published library and improve their metadata.

Summary​

Use this model:

  • Signature: the thing you care about
  • Library: the container you use to work, share, and curate

Then let the library evolve:

  • Private while experimenting
  • Project when sharing with a team
  • Published when curated and reusable
  • Archived when no longer active