Second line of work
A fibre-optic guided drone emits nothing at all, so no amount of signal processing finds it. It is also tied to ten kilometres of glass it cannot drop. That thread is what we look for — and a line has two ends.
Threat
01Principle
02A quadcopter at range is a handful of pixels — statistically indistinguishable from a bird, a bag, or sensor noise. Detectors that hunt for it drown in false positives.
The fibre is the opposite kind of object. It is continuous, near-perfectly straight, and long enough to cross the entire sensor frame. You are no longer classifying a blob, you are fitting a line through thousands of correlated pixels. Noise does not form lines. Birds do not form lines.
And a line has two ends. The near end is the aircraft you have to shoot down in the next few seconds. The far end is the launch team you can hand to fires at your leisure.
Sensor frame · simulated
Toggle the search modeSwipe the frame to see all of it →
Blob search scores every small bright region on its own. Most of what it returns is noise, and the true target scores no better than the clutter around it.
Line search accumulates evidence along a hypothesis. Thousands of weak pixels that happen to be collinear sum into one strong detection, and the two endpoints drop out of the fit.
Illustrative render — not a measured detector output.
System
03A helium aerostat carries the eye above the terrain that hides the threat, and the shooters ride with it. Height does two jobs at once: it clears the relief the drone is using to mask itself, and it puts the sensor at a depression angle, so the fibre is seen against ground clutter rather than lost against a bright sky.
A directed-energy mount sits behind the anchor for everything that comes close enough to burn.
General arrangement · 3 assemblies
Select a component · drag to orbitEngagement
04Set the threat range, pick an effector and commit. The engagement plays out from first contact to launch-point cue, sensor view included. Drag the stage to take the camera.
Ranges, closing speeds, effector selection and standoff are all inputs to a parameterised model — change them and the outcome changes with them. It is a model, not a measured result.
Engagement simulation · 72 s
Parameterised modelTerrain is generic. Aircraft are drawn oversize to stay visible at scale. The approach phase runs time-compressed and engagement timings are indicative.
Design targets
05Sensor altitude, detect-to-defeat, magazine and standoff are illustrative concept figures — chosen to size the system, not derived from test data or from a fielded article. Line detection range is the exception: it is the output of the detection model.
The fibre trails downwind behind the drone, so range depends on the angle you view it from and on how much the air is shimmering. Side-on, in nominal air, the model gives 8 km; viewed end-on it foreshortens to about 6 km, and a hot afternoon over sand costs a further kilometre or two. The working envelope is roughly 4 to 9 km.
Two inputs to that model have no experimental backing: how strongly the fibre stands out against the sky, and how precisely the sensor can be held steady on a tethered platform. Both need measuring before any range here is claimed as demonstrated rather than modelled.
Deployment
06The fibre streams downwind behind the drone, so a sensor aimed straight at the target is looking up the length of the thread and sees almost none of it. Sites are therefore placed in a chain and aimed along the border at one another, which puts every crossing point side-on to somebody.
Roughly five sites at 16 km spacing hold a 60 km frontage, and the overlap means a target on a seam is held by two line fits.
Deployment schematic
Not to scaleSwipe the schematic to see all of it →
Key
Nothing on this site covers that. Try one of the suggestions, or press Esc and read on.
Try