Area of Interest (AOI)
Define geographic regions of interest — by continent, country, or custom polygon — and compute satellite visibility over them with optional illumination filtering.
An Area of Interest (AOI) is a geographic region on the Earth’s surface that you want a satellite to observe or communicate with. AOIs are used as targets in access computations — instead of asking “when can my satellite see a ground station?”, you ask “when can my satellite see this region?”.
AOIs are Earth-only. Moon satellites cannot compute access to Earth AOIs.
Creating an AOI
When you create an AOI, you choose a region type and give it a name and display color.
Region types
| Type | Description |
|---|---|
| Continents | Predefined continental land masses (Africa, Asia, Europe, North America, South America, Oceania, Antarctica) or all land combined |
| Countries | Predefined country boundaries, filterable by continent and searchable by name |
| Custom | Draw a polygon on the globe or upload a GeoJSON file |
You can combine multiple regions in a single AOI — e.g. select several countries together.
Custom polygons
In the Custom tab, you can:
- Draw on the globe — click to place vertices, forming a polygon on the 3D globe. You can undo the last point and drag existing vertices to adjust the shape.
- Upload a GeoJSON file — import a
.geojsonpolygon (Polygon or MultiPolygon geometry). The first polygon found in the file is used.
Custom polygons are stored as GeoJSON and rendered on the globe with your chosen fill color, outline color, and opacity.
Display settings
Each AOI has configurable display properties:
- Fill color — the polygon fill color (with a color picker).
- Outline color — the polygon border color.
- Opacity — fill transparency (0–1).
Using AOIs in access analysis
AOIs are used as the target (Object 2) in access computations. You select a satellite (or constellation) as Object 1 and an AOI as Object 2. The computation returns every visibility window — the time intervals when the satellite’s sub-satellite point falls within the AOI polygon.
Illumination filtering
When computing satellite-to-AOI access, you can optionally filter visibility windows by solar illumination conditions on the ground:
| Setting | Description |
|---|---|
| Enable illumination filtering | Toggle on to filter by sun elevation |
| Mode | Daylight Only (sun above threshold) or Night Only (sun below threshold) |
| Threshold (°) | Minimum sun elevation angle. e.g. 0° for horizon, 18° for astronomical night |
This lets you answer questions like “when can my satellite see this region during daylight?” — useful for optical imaging missions where the ground must be lit.
Sensor-to-AOI access
If your satellite has a sensor defined (via the Model tab), you can compute sensor-to-AOI access, which accounts for the sensor’s field of view and pointing direction rather than just the sub-satellite point. This gives you the windows when the AOI is within the sensor’s footprint.
Next steps
- Access — how visibility windows are computed and used
- Satellites — satellite setup and propagation
- Model — define sensors for sensor-to-AOI access