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ARGUS User Manual

SAR search-grid generator

The SAR grid generator turns a polygon into a ready-to-fly parallel-line search pattern — the coverage primitive every search-and-rescue sortie starts from. Under the hood it writes a search_grid polygon (PolygonDraft.grid with pattern: 'parallel' | 'creeping-line' | 'expanding-square' | 'sector') which a DroneMission can then consume.

Creating a grid

From the ops-map tile:

  1. Draw a polygon of type SAR (or custom).
  2. Right-click inside the polygon → Generate SAR grid. Same action is on the map toolbar’s grid icon.
  3. In the grid dialog configure:
    • Pattern (PolygonSearchPattern) — parallel, creeping-line, expanding-square, or sector. Start with parallel for most SAR.
    • Sensor FOV (degrees) — drives the effective ground swath.
    • Altitude (grid.altitudeM) — metres AGL; combines with FOV to set swath.
    • Altitude mode (grid.altitudeMode) — terrain (per-point AGL against DEM) or uniform (flat).
    • Overlap % — typical 20-30 %, shrinks effective swath → tighter spacing.
    • Spacing (grid.spacingMeters) — auto-computed from swath × (1-overlap); you can override.
    • Bearing (grid.bearingDeg) — initial line direction, degrees from north.
    • Buffer / turn radius (grid.bufferMeters) — padding outside the polygon edge to give the aircraft room to U-turn.
  4. Preview the generated lines on the map.
  5. Click Save as search grid — commits the grid block onto the polygon.

How swath is computed

ARGUS computes ground swath as

swath_m = 2 × altitudeM × tan(FOV / 2)
spacing_m = swath_m × (1 - overlap / 100)

Lower altitude or narrower FOV tightens the grid. The generator also accepts grid.pointAltOverrides (per-waypoint altitudes) and grid.waypointActions (per-waypoint action lists) so you can edit individual turnpoints without regenerating.

Handing the grid to a drone mission

A search_grid polygon is not a flight plan on its own — it’s a reusable coverage primitive. To fly it:

  1. Right-click the polygon → Plan drone mission from polygon.
  2. In the planner, pick parallel (or the matching pattern) — the planner reuses the polygon’s stored spacingMeters, bearingDeg, bufferMeters, and altitudeM.
  3. Tweak speed, turn mode, heading mode, finish action as needed.
  4. Save + assign + dispatch.

Each grid line becomes a pair of turn waypoints; the planner fills in entry and exit points outside the polygon so the aircraft has a stable run-in.

Multi-aircraft coverage

For an area too large for one airframe:

  1. Split the original polygon into sub-polygons with the polygon editor.
  2. Generate a grid per sub-polygon (same FOV / altitude / overlap so coverage lines up at seams).
  3. Assign each grid to a separate drone or dock. For corridor work also see multi-dock relay, which chains dock SNs via dockChain with multiDockMode: 'relay' | 'simultaneous'.

Editing an existing grid

Opening the polygon editor on a search_grid polygon re-opens the generator with the stored values. Regenerating keeps pointAltOverrides and waypointActions where the waypoint indices line up; new or deleted waypoints clear their overrides.