Three ways to get a sensor up high#
| Fixed tower | Mobile trailer | Aerial sentry | |
|---|---|---|---|
| Typical sensor height | 10–40 m | 6–9 m mast | Perch height + ~2 m mast |
| Time to move | Weeks (new install) | Hours (tow, level, raise) | Minutes (flies) |
| Placement flexibility | Where foundations go | Where a vehicle can reach | Roofs, ridges, light towers |
| Power | Grid | Solar/battery/generator | Battery + solar on perch |
| Regulatory overhead | Planning permission | Minimal | Aviation authorization |
What the viewshed study says#
Our viewshed simulation across 30 synthetic sites found that a 9 m mast sees about twice the ground of a 2 m post (28.3% vs 13.9%) and a 40 m tower about 68.7%. More striking: two greedily placed 9 m masts (53.1%) matched six placed at random (57.3%). In the same study, sentries perched 2 m above high points did slightly worse than greedily placed 9 m masts — so perch height matters, and our deployments favour tall structures.
Where each wins#
Towers win on permanent sites with stable layouts and grid power. Trailers win on temporary and construction sites where coverage needs to change every few weeks. Aerial sentries win where coverage needs to change every few hours — after a detection, as a site's operations move, or to deny an adversary a stable picture of the posture.
Combine them#
The strongest designs use masts or towers for wide-area radar detection and sentries for close identification near each detection. Distance to target matters for resolution as much as height (see DORI): a sentry that relocates to 150 m from a track doubles pixel density compared with a 300 m tower view.
Frequently asked questions#
Is a mobile surveillance trailer as good as a tower?
For temporary sites, often yes: masts of 6–9 m capture most of the coverage gain from height. Towers win on permanent sites needing more height.
How high should a surveillance mast be?
In our 30-terrain study 9 m doubled coverage versus 2 m, but placement mattered more than extra height.