Who Invented The Rangefinder? – Detail Overview

People often ask, who invented the rangefinder?

Let’s find out!

Who Invented the Rangefinder?

The first rangefinders were invented by a man named William F. Baldwin in 1894, but he didn’t patent his invention until 1896.

The first commercially successful rangefinder was invented by an Englishman named John Lea and patented in 1897. He called it the “Leaf-spring Gun Finder” (LSGF). It was manufactured by the British firm Wm. Lewis & Son Ltd.

Laser Rangefinder

Lasers range from handheld devices to large stationary units. These devices use lasers to determine distance by measuring the length of the laser beam.

A range finder uses lasers because they have very accurate and precise measurements.


To prevent the rangefinders from being jammed, they may be coded to detect objects approaching or receding from them. They could then adjust their settings accordingly.

This allows a simple yes/no answer as to whether the target has been detected. It may also provide some indication of where the radar is pointed. If this is not available then it means that the target is either completely obscured by other objects or is too far away for the radar to detect.

Range and Range Error

Despite the fact that the laser beams are so narrow, they will eventually diverge because of the divergence of the laser beams, as well as because of scintillation and beaming errors, which occur when there are air bubbles in the atmosphere acting as lenses ranging in sizes from microscopic to roughly half of the laser beams’ paths above the Earth.

Atmospheric disturbances combined with the divergent nature of the laser beam and with lateral wind currents that push the atmospheric heat bubbles sideways may cause difficulties when trying to measure objects at greater distances than 1 kilometer in open and unobstructed desert terrain.

Some of the laser beam might bounce back from nearby objects, causing an early return and a lower reading. If the distance between the target and the sensor is greater than 1,200 feet (365 meters) then the target could disappear into a mirage. These effects have to be considered.


The distance between two locations is given by the length of the shortest path between them.

Where c is the speed of sound and t is the time required for the round trips between A and B.

where φ is the phase delay made by the light traveling and ω is the angular frequency of the optical wave.

Then substituting the values in the equation,

If we assume that the speed of light is constant, then the distance between two points is proportional to the time taken for a signal to travel from one point to another.


This measures the amount of delay between sending out a signal and receiving the echo. By measuring the delay, the distance can be determined. A number of signals are sent out simultaneously and the average response is measured.

This method does not require any special equipment and works best where there is no interference.

Multi-frequency PSI – this measures the difference between the phases of multiple signals at different times, then uses some simultaneous equations to solve for the final result.

The most accurate and best way to measure changes in distance rather than just absolute distances.



A rangefinder provides an exact measurement of distances to objects located beyond the range of point-blank firing by snipers and artillery. It can also be useful for military reconnoitering and engineering.

Handheld military range finders operate at distances ranging from 2 kilometers up to 25 kilometers and are typically used in conjunction with binoculars or a monocular. They are often equipped with digital magnetic compasses (DMC), inclinometers, and a laser rangefinder.

Rangefinder units may also include a GPS receiver, a barometric altimeter, and/or a thermal imager. Some rangefinder units can also measure a target’s velocity relative to the user. Some rangefinder devices utilize standard or rechargeable batteries, while others employ disposable batteries.

Rangefinder models that can cover distances from 0 to 25 kilometers (0 to 16 miles) are called long-range models. They’re usually mounted on tripods or vehicles. Some of them are equipped with computer systems for processing data. Others are designed to be used by soldiers who need to know their exact position at any time.

Some military arms may have developed paints that absorb lasers so they’re not effective at shooting down aircraft. However, some things don’t reflect lasers very well, and trying to use a rangefinder on them is hard.

The first commercially successful laser rangefinder was the B&S Barr & Stroud LF1, which was developed in conjunction with Hughes Aircraft Company (now part of Boeing) and made its debut in 1965.

It was followed by the Barr & Stroud LF2, an improved version that incorporated the rangefinder into a sighting device for tanks, and this was used in the Chieftain Mk 1 main battle tanks in 1969. Both devices used ruby lasers.

Who Invented The Rangefinder?

Who Invented The Rangefinder?

3-D modeling

A LIDAR scanner uses a laser beam to measure distances to objects. It has a horizontal rotating mechanism for scanning horizontally, and a vertical flipping mechanism for scanning vertically.

Lasers are widely employed in 3-D modeling, 3-D recognition, and a wide variety of other computer-related applications. These devices constitute the heart of the so-called “laser rangefinder” scanners. In contrast to military instruments, lasers provide high-precision scans, with either single face or 360-degree scan modes.

There are several different types of computer vision techniques for merging a range of data into three-dimensional objects. One advantage that lasers provide over other methods of computerized vision is that they don’t require any sort of correlation between features from two images to create a three-dimensional representation of an object.

Triangulation and refraction measurements are commonly employed for measuring distances in computer vision applications. These methods are typically faster than the laser pulse technique employed in LIDAR systems.


Special lasers are often employed in forestry. They have anti-leaves filters and work with reflectors. A beam of light reflected only from this reflector guarantees an accurate distance reading. Anti-leaves filters are utilized for instance in forest inventories.


A range finder is an optical instrument used to measure the distance between two points. They are often used in conjunction with firearms, especially rifles, to help determine the correct shot placement. Range finders are also used in surveying, construction, agriculture, geology, mining, forestry, and military applications.

Industrial Production Processes

A key example of an important field of applications for laser rangefinder technology is the automated control of stock management systems and manufacturing processes in the steel industry.

Laser Measuring Tools

Lasers are also widely employed in various fields including architecture, surveying, engineering, manufacturing, and scientific research. They are often preferred because they do not require any physical contact with the surface being measured, and thus are safer to use around flammable materials.

In addition, lasers are capable of producing highly precise results without requiring human intervention. For example, a surveyor could take multiple readings of a building’s height and width with a single device. A carpenter could use a similar device to determine the dimensions of a wooden beam.


We hope that this article is helpful. If you have any queries feel free to reach out in the comments section below.


  • Herman Riggs

    Herman is a writer, researcher, and product reviewer here at The Outdoor Stores. His knowledge and expertise in firearms are immense. He knows well which gun is suitable for which purpose and how to handle it correctly. You can benefit from his passion by reading his posts on this website.

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