Measuring Difficult Targets: Why Multipulse LRFs are superior in challenging conditions

“For reliable Laser Rangefinding, laser power alone does not determine performance. Equally important is the module’s ability to recognize and process weak reflected laser signals.”

Accurate distance measurement is straightforward when targets are highly reflective and environmental conditions are favorable. Military operations, however, rarely offer such ideal circumstances.
Whether measuring distant targets, operating through smoke or haze, ranging to low-reflectivity surfaces, or engaging targets at difficult angles, laser rangefinders can struggle to deliver reliable results. In mission-critical situations, uncertainty is not an option.
Ultisense laser rangefinders address these challenges with Multipulse Technology. Rather than relying on a single laser pulse, Ultisense LRFs transmit and process multiple ultra-short laser pulses within a fraction of a second. By intelligently analyzing numerous returns, the module can reliably distinguish genuine target reflections from noise and interference.
The result is robust and accurate range performance, even when conditions are far from ideal.

Why difficult targets challenge laser rangefinders

Laser range measurement relies on detecting laser energy reflected from a target while accurately measuring the time-of-flight of the laser signal. When reflected signals become weak, the module’s receiver may struggle to detect them reliably, resulting in measurement failures.

Several scenarios can create these conditions.

1. Distant targets and low visibility

As target distance increases, the amount of reflected laser energy reaching the receiver decreases significantly. Atmospheric absorption, scattering, and environmental noise further weaken the signal, particularly in low-visibility conditions.
Many laser rangefinders available on the market are Single pulse lasers, measuring only with one laser pulse. Such modules depend heavily on favorable environmental conditions to receive a sufficiently strong return signal. If this signal is too weak or cannot be detected, the complete measurement fails. Ultisense Laser Rangefinders overcome this limitation by using multiple laser pulses for each distance measurement instead of relying on a single pulse. By intelligently combining the responses from up to thousands of reflected signals, the module can distinguish valid target echoes from background noise and maintain accurate ranging performance even when some individual pulse reflections are weak.

2. Measuring Through Smoke, Haze,…

Atmospheric conditions such as smoke, dust, and atmospheric haze introduce countless small reflective particles into the laser path. These particles create false returns and attenuate the signal before it reaches the actual target. The results are unstable readings or even complete measuring failures. Multipulse Technology significantly improves the performance in these difficult environments. By thoroughly analyzing multiple returns, the module is able to identify consistent real target reflections while filtering out useless reflections. This increases the probability for reliable measurements dramatically.

3. Targets with low reflectivity

Not all targets reflect laser energy efficiently. Camouflage nets, dark coatings, stealth materials, and certain composite surfaces are specifically designed to reduce their reflectivity. As a result, only a small fraction of the transmitted laser energy is returned to the module’s receiver, producing weak return signals that can make distance measurement challenging. Simply increasing the laser power is also not a viable solution. If the transmitted laser power is too high, strong target reflections can saturate or even damage the receiver. To overcome these limitations, Ultisense laser rangefinders optimize the transmitter parameters at the beginning of each measurement ensuring reliable range performance under different operating conditions.

4. Non-perpendicular measurements

The ideal laser measurement occurs when the target surface is perpendicular to the laser beam. In real world and mission-critical scenarios, this is often not the case. When a target is illuminated at a significant angle, a large portion of the reflected laser beam is redirected away from the receiver rather than back toward it. This reduces signal strength and increases measurement uncertainty. Multipulse Technology compensates for these weaker returns by collecting and processing multiple reflected pulses during one measurement. The result is higher reliability when targeting objects at difficult angles.

Multipulse technology: The key for reliable performance when conditions are not ideal

At Ultisense, Multipulse Technology is a key enabler of reliable range performance. Across the entire product portfolio, the same principle applies: By intelligently analyzing and processing a large number of returns, Ultisense laser rangefinders maintain high performance even under challenging conditions. The result is accurate and reliable distance measurements, that soldiers can rely on when it matters most.

Interested in learning which Ultisense solution best fits your application?
Contact our team directly for a technical consultation.
We would be pleased to discuss your ranging requirements and help identify the optimal solution for your system.