Laser Rangefinder for Vehicle Fire-Control Systems
A vehicle fire-control system needs a range to the target, fast, at any time of day, in dust and vibration, and it needs that number to be trustworthy enough to compute a firing solution.
The vehicle environment
- Vibration and shock from the hull, the engine and the gun. Much of it below 100 Hz and much higher amplitude than an airborne case.
- Dust and mud on the optics. A window wiper or purge is not optional in some theatres.
- Temperature extremes and rapid soak from a cold start or from firing.
- Electromagnetic environment from radios, motors and the fire-control computer.
Module candidates
| Model | Pulse energy | Divergence | Mass | Notes |
|---|---|---|---|---|
| LDR20K1 | ≥ 20 mJ | ≤ 0.6 mrad | ≤ 290 g | lightest, short range |
| LDR40K1 / LDR40K3 | ≥ 40 mJ | not published | 420–460 g | mid range |
| LDR60K1 | ≥ 60 mJ | ≤ 0.3 mrad | ≤ 680 g | 10 km class |
| LDR80K1 | ≥ 80 mJ class | ≤ 0.30 mrad | ≤ 680 g | 10 km class, higher energy |
For a main battle tank fire-control system, a 10 km class module with 0.3 mrad divergence covers typical engagement geometry with margin. For an infantry fighting vehicle, a 3–5 km module at lower mass is usually sufficient.
Range gating matters in a vehicle
Vehicle fire-control often ranges through foreground clutter — vegetation, terrain, dust. Range gating lets the module ignore returns outside a window you define, which suppresses clutter and prevents a false short range from corrupting the firing solution.
Confirm that gating is commandable from the host and that the gate window can be set in metres, not just in discrete steps.
Interface on a vehicle
If the platform already has a CAN bus, making the rangefinder a bus node avoids a dedicated harness run through the turret. If not, RS-422 point-to-point is simpler and deterministic. Either way:
- specify message IDs and timing before integration
- plan for electromagnetic interference on long harness runs
- ensure digital ground, power ground and housing are isolated
Self-test and confidence
A fire-control system needs to know the range is real. Look for:
- power-on self-test and periodic self-test with reported status
- per-pulse status alongside the range value
- cumulative pulse count, for predictive maintenance
- a defined behaviour when no valid echo is returned
Reporting "no return" is far better than reporting a plausible but wrong number.
Frequently asked questions
What range does a tank fire-control system need?
Typically 5–10 km with margin; the engagement range is shorter, but ranging early improves the firing solution and allows target identification.
Can a vehicle rangefinder designate targets?
Yes — dual-function modules exist. Whether you need designation depends on whether the platform guides laser-guided munitions.
How is dust handled?
Through window purge or wiper, and by specifying a coated window that tolerates cleaning. The module itself is sealed; the aperture is the vulnerable surface.
Does vibration affect accuracy?
It affects boresight stability, which affects whether the range corresponds to the reticle. Module-level survival is a separate qualification.
See the rangefinder collection or read range classes explained.