Breaking down the Ability to Measure to a Target Using a Laser Sensor

By T Girmann, 12/09/13

Laser Technology, Inc. (LTI) realized there was a need for laser sensors that could handle challenging environments. So, we engineered the laser sensor measurement tools to do just that, from working in dusty conditions to measuring moving targets or liquids. To accomplish this, it remains imperative to understand what determines the ability to measure to a target using a laser sensor. 

Laser Technology Laser Sensors Designed For Tough Situations 

What determines the ability to measure to a target using a laser? When a measurement is taken, several actions happen and many conditions exist. First, consider the laser sensor’s power. The stronger the laser power the stronger the signal, which furthers range. There is a tradeoff though, between the laser power, laser pulse rate, and eye safety rating. 

Beam divergence is another consideration. All light diverges or converges despite best efforts to minimize this through the use of optics. The larger the divergence the more dispersion the beam is undergoing, which will lessen the overall range of the laser. For example, a laser beam diverging at 3mrad with a free aperture of 5 cm will measure 35cm at 100m. 

The pulse rate frequency will dictate how fast a target is acquired. A faster pulsed laser sensor will acquire a target much quicker because of the increased number of pulses reflected from a target and returned back to the sensor. The receive performance is important, as well as the photodiode, which needs to be able to sufficiently acquire and process the returned signal. 

Ambient conditions such as fog or dust in the air may inhibit a laser measurement. The ability of the laser sensor to overcome this interference is important. The TruSense^® S-Series are just one of the laser sensor products designed by LTI that are user-configurable. This allows you to set the laser with the best optimization to handle the specific application you need to measure. 

LTI’s laser sensors have different modes capabilities. Target discrimination modes allow the sensor to “choose” the correct target. For example, when utilizing Last Target mode, the laser sensor will compare many returned signals and output the farthest range. 

When measuring to a target it is important to remember that the target characteristics, ambient conditions, and laser performance all play a role in measurement accuracy and the ability and speed to acquire the target.