Compose Coverage

A Compose Coverage merges any subset of an Area of Interest’s individual coverages into a single combined coverage layer. While an individual coverage measures what one satellite sensor sweeps over an AOI, a Compose Coverage answers fleet-level questions: how much of this region do my satellites cover together, how often does the fleet revisit each grid cell, and what is the combined response time?

Prerequisites

Before creating a Compose Coverage on an AOI:

1. Define an Area of Interest on Earth.
2. Add two or more individual Coverages to that AOI (for example, different satellites in a constellation or multiple sensors on the same spacecraft).

Creating a compose coverage

1. In the Scenario tab, open the AOI’s more options menu (...).
2. Select Add Compose Coverage.
3. In the Compose Coverage settings modal, configure:

Field	Description
Compose Coverage Name	Display name shown as a child row under the AOI (marked with a union icon)
Figure of Merit	Simple Coverage (solid swath) or a fleet-wide spatial heatmap metric (Revisit Count, Mean Revisit Gap, Max Revisit Gap, Response Time)
Color / Color Scheme	Solid swath color (for Simple Coverage) or heatmap color gradient and grid resolution (for Figure of Merit modes)
Included Coverages	Checklist of the AOI’s individual coverages to combine (with Select all and Clear shortcuts, color badges, and per-coverage area percentage or computation status)
Opacity	Swath or heatmap fill transparency (5–100%)
Show coverage on globe	Enable or disable the 3D globe overlay without deleting the entry

4. Click Add Compose Coverage (or Save when editing).

A Compose Coverage automatically triggers backend computation for any included individual coverages that have not been computed yet, even if those individual coverages are currently hidden on the globe.

How compose coverage aggregation works

Rather than simply summing individual coverage percentages (which would double-count overlapping swaths), Compose Coverage performs a true geometric and chronological aggregation across all passes from the selected individual coverages:

1. Chronological pass sorting — all activation windows from all included coverages are merged into a single timeline sorted by pass start time.
2. Spatial union in equal-area projection — each pass footprint is unioned against the cumulative area already covered by earlier passes from any included satellite/sensor in the AOI’s local Lambert Azimuthal Equal-Area (LAEA) projection.
3. Incremental new-area attribution — for each pass in the combined timeline, SMD computes both the total area swept during that pass (Covered area) and the incremental New area that had not yet been observed by any earlier pass in the fleet.

Fleet-level Figure of Merit (FoM) heatmaps

When you select a Figure of Merit on a Compose Coverage, the metric is evaluated across the combined pass history of all included coverages at every cell of the AOI grid:

Figure of Merit	Fleet-level meaning
Simple Coverage	Cumulative unioned ground swath painted in a single solid color as passes from any included coverage occur over time
Revisit Count	Total number of passes (across all included satellites/sensors) that cover each grid cell
Mean Revisit Gap	Average time gap between consecutive passes (from any included coverage) over each cell
Max Revisit Gap	Worst-case time gap without coverage from any included satellite/sensor at each covered cell
Response Time	Elapsed time from the scenario start until the first pass from any included coverage reaches each cell

You can customize the Color Scheme (Turbo, Viridis, Plasma, Inferno, Cool–Warm, Red–Yellow–Green, or Custom Colors with Low/High pickers) and Grid Resolution (Coarse (120) up to Extreme (900)) instantaneously without re-running backend swath computations.

Composed Coverage report

Open the Coverage Report from a Compose Coverage’s row menu (... → Coverage Report):

• Coverage Summary — total unioned area covered by the combined coverages (km²), total AOI area (km²), and overall percentage of the AOI covered, with a progress bar.
• Activation — total number of passes across all included coverages, combined activation time, and first/last coverage UTC timestamps.
• Figure of Merit — grid dimensions and cell resolution, plus fleet-wide summary statistics across covered cells:
  • Revisit count (average and maximum passes per cell)
  • Revisit gap (average of mean revisit gaps and maximum revisit gap across the fleet)
  • Response time (average and maximum time from scenario start to first observation)
• Per-window table — lists every pass chronologically with a Coverage column (and color badge) identifying which individual coverage contributed the pass, alongside Start (UTC), Stop (UTC), Duration, Covered (km²), incremental New (km²), and % AOI. Double-click any Start or Stop cell to jump the simulation clock to that timestamp.
• CSV export — click CSV in the report header to download the composed summary, list of included coverages, FoM statistics, and per-pass table.

Time-series plots

In the Scenario tab’s Time-Series Plot builder, select Coverage as the object type. Both individual coverages and Compose Coverages appear in the object selector, allowing you to plot fleet-level growth curves over the scenario interval:

• Cumulative New Area (km²) and Cumulative New Coverage (%)
• Cumulative Covered Area (km²) and Cumulative Coverage (%)

Next steps

• Coverage — create and configure the individual satellite/sensor coverages that feed a Compose Coverage
• Area of Interest — define the geographic regions coverages are measured against
• Sensor — configure sensor fields of view and orientation frames (Body vs. LVLH)
• Access — compute the visibility windows that drive coverage activation