Coefficients

LIME Toolbox requires coefficients to run its LIME model equations for reflectance (and consequently irradiance) and for the Degree of Lunar Polarisation (DoLP).

These models are continuously updated, improving their accuracy with each new coefficient release.

Updating the Coefficients

To update the coefficients, navigate to “Coefficients → Download updated coefficients” in the action menu bar.

A window will appear indicating that the coefficient download is in progress, as shown in Figure 23.

Window displaying coefficients download in progress

Figure 23: Coefficients download in progress.

Once the process is complete, the window will display:

  • The number of new coefficient versions downloaded.

  • Any errors encountered during the download.

The result may indicate that new coefficients were downloaded (Figure 24) or that no new updates were available (Figure 25). If there was an issue connecting to the coefficients server, an error message will be displayed (Figure 26).

Window displaying that there was one new coefficient version

Figure 24: One new coefficient version.

Window displaying that there were no new coefficients

Figure 25: No new coefficient updates available.

Window displaying that there were errors downloading the coefficients

Figure 26: Error downloading the coefficients.

Updating the Coefficients via CLI

Users can also update coefficients via the command-line interface (CLI) using the -u or --update option:

lime -u

Selecting a Coefficients Version

To use a specific coefficient version, navigate to “Coefficients → Select coefficients” in the action menu bar.

A window will appear, displaying a dropdown menu containing all available coefficient versions (Figure 27). To change the version:

  1. Open the dropdown menu.

  2. Select the desired coefficient version.

  3. Click “SAVE” to confirm the selection.

Window displaying coefficient selection options

Figure 27: Selecting a coefficient version.

Choosing the Coefficients Version via CLI

To choose a different coefficient version through the CLI, use the -C or --coefficients option:

lime -C SELECTED_COEFF_VERSION_NAME

This updates the coefficient version for all subsequent simulations and applies immediately to the current simulation if used alongside any simulation or comparison option.

Example: To select the coefficient version 20231120_v2:

lime -C 20231120_v2