Viewshed Tool

The Viewshed Tool is a standalone line-of-sight calculator for DCS theaters. Drop a radar or SAM position on the map, set the radar's antenna height and the aircraft's ingress altitude, and the tool computes the terrain-masked shadow — the area that is hidden from the observer by the terrain in between.

Open the tool by navigating directly to /tools/viewshed.

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The Viewshed Tool is a planning surface only — nothing you do here is saved to a design. Use it to sanity-check low-level ingress routes, pick a masked run-in heading, or see where a SAM can and can't see. To bake viewshed results into a kneeboard, use the in-map viewshed feature from the Tactical Map instead.

Placing an Observer

Pick a Theater from the selector in the configuration panel on the right. The map jumps to that theater's default view.
Click anywhere inside the theater boundary to drop an observer. The tool immediately renders a coarse viewshed, then refines it to the full resolution.
Clicking outside the theater boundary shows a transient error — observers must be placed inside the mapped theater.

Once an observer is placed, further map clicks do nothing. To move the observer, drag its marker to a new position — a coarse preview follows while you drag, and the high-resolution shadow recomputes when you drop.

To start over, use Clear Observer at the bottom of the configuration panel.

Observer Settings

The Observer Settings section appears once an observer is placed:

Radar Height (ft AGL) — Height of the radar antenna above the ground. Defaults to 20 ft. Numeric input.
Ingress AGL (ft) — Aircraft altitude above ground level. Defaults to 500 ft. Slider from 0 to 20,000 ft.
Enable MSL altitude — Checkbox that exposes a second slider for absolute altitude.
Ingress MSL (ft) — Only shown when MSL is enabled. Aircraft altitude above mean sea level, 0 to 20,000 ft.

Changing any of these re-runs the viewshed against the same observer position.

Legend

The configuration panel includes a color legend for the overlay:

Terrain shadow (AGL mode) — Blue fill over areas the observer cannot see at the configured ingress AGL.
Below MSL altitude — Darker fill shown only when MSL mode is enabled; marks terrain that sits above the chosen MSL ingress altitude, i.e. places the aircraft can't physically fly through at that altitude.
Observer position — The blue marker you placed.

State Persistence

The theater, observer position, observer settings, and the map's center and zoom are saved to your browser's local storage, so re-opening the tool restores the last session you were working on. Use a different browser or clear site storage if you want a clean slate.