Tag: total stations

Earlier this year, we looked back at 2020 and reviewed how surveying has dealt with the worldwide pandemic while adapting to the new tools and technology being created. We discovered the need for surveyors did not diminish during this crisis, and in many places the demand has gone up significantly. Instruments, computers and measuring methods continue to increase in capability and complexity to help with the shortage of qualified field crews, yet we still need to expand our efforts to find the next generation of surveyors.

How do we find those future geospatial experts, data collectors and surveying professionals? The answer is right under our noses, and our current group of practitioners needs to get the word out.

What is the word, you ask?

Technology.

Younger generations understand technology better than most practicing surveyors. New devices, methods and operations are being invented at a fast pace, and our best and brightest should be considering using that technology in a rewarding career. Before we make the big pitch to them, however, we should refresh our understanding of recent surveying history to better understand why technology is a good thing.

How did we get here? A short historical look at measuring

The measurement methods, devices and instruments used by surveyors have radically changed in the past 50 years, and we have covered their evolution in past columns (Survey Scene May 2016, May 2017 and Sept. 2019).

Instruments and devices used by surveyors vary in their function and output of information. Some are used to physically measure the distance from a stationary point to another, determine horizontal and vertical angles at a specific location, or determine grade differentials between various points. Other instruments are used to determine horizontal or vertical positions to establish locations and elevations. All these instruments are being used to gather positional data on any number of items, but the quality of the information may vary depending on the technology and method used. How?

Devices and methods for measuring distances

Tools for measuring distances have been around for centuries. The Egyptians are famous for their “rope stretchers,” while early surveyors in Europe and the New Colonies were known to use the Gunter’s chain and a measuring wheel. In the early 1800s, steel tapes were invented to replace the chain. These measuring tapes continued to evolve well into the 20th century with varying metals, fiberglass and nylon-coated plastics.

In the mid-20th century, scientists and physicists began to experiment using light waves as a means of measuring terrestrial distances. These experiments led to the development of the first electronic distance meter (EDM), commercially produced by the Swedish company Svenska Aktiebolaget Gasaccumulator (AGA) in the early 1950s. Other methods of electronic measurement, including microwave and infrared wave technology, were also developed in the years following the introduction of the lightwave EDM.

For many years, the EDM was used independently from transits or theodolites to measure long distances. For those who needed to consistently measure long distances, the invention of the EDM was not just a time saver, but also provided much higher accuracy than manual measurements.

Other technologies were developed in the latter part of the 20th century, introducing the surveyor to laser scanning, but we can defer this topic until later in this column.

Devices for measuring angles

The surveyor, like the astronomer, has consistently been at the forefront of developing optical instruments. The key has been combining high optical quality with a means of measuring horizontal and vertical angles within the instrument. The creation of the theodolite and the transit revolutionized the ability of the surveyor to accurately measure angles and apply trigonometric functions to determine mathematical computations. In addition, the surveyor’s compass was also developed to assist with angle measurement — with less accuracy but greater flexibility.

By the 1920s, optical theodolite technology was rapidly improving through the work of Switzerland’s Heinrich Wild. Beginning with the T2 and T3, these instruments provided accuracy and precision not previously available to the surveyor. Other manufacturers followed suit with similar instruments for the next several decades and were used in conjunction with the EDM for larger surveys. Anticipation grew with the competition to see which instrument company could marry the theodolite and the EDM into one easy-to-use, yet accurate, optical instrument.

Introducing the total station

By the late 1960s, technology had firmly entered the surveying world with a few electronic advancements. In 1968, Zeiss — a German company known for its lenses and optical systems — produced the first known tachymeter, combining a theodolite with an electronic distance meter. The tachymeter became better known as the total station, as it was capable of measuring angles and distances in one instrument. While somewhat crude and hard to use, the Elta 14 total station introduced the world to a future generation of surveying instruments that would revolutionize the field.

In the course of a few years, several manufacturers developed their own total stations. The biggest hurdle was combining the optics of the scope with the measuring axis of the EDM. By the end of the 1970s, most total stations were coaxial, therefore measuring angles and distances was done with one sighting.

Robotics were introduced in the early 1990s, with two servo motors to drive the horizontal and vertical movements of the total station. These movements were controlled remotely by the tracking system connected to the prism pole and data collector. Not requiring a human being to remain stationary and manually operate the total station provided cost savings and additional efficiency for the field crew.

Positions, everyone! Positions!

Positional measurement has revolutionized not just the surveying profession, but a large portion of everyday tasks as well. From monitoring travel times for your commute to providing your food-delivery driver with your location, position determination is the key element to these services. Satellite navigation is now the primary technology used for positioning, navigation and timing (PNT) and a big part of most aspects of surveying.

Remote sensing

Here is where we can discuss laser scanning and other remote sensing technologies. Remote sensing is the science and technology of gathering data from a distance. Traditionally this has been mostly done from aircraft, satellites and vessels. However, technology has expanded so that most practitioners now consider the use of laser scanning, lidar, photogrammetry, hyperspectral cameras, bathymetric sonar and simultaneous localization and mapping (SLAM) to be included in the category. Keep in mind that all these technologies are types of measurements; they are not the vehicle or instruments used for the measurement.

These various sensor types can collect millions of data points in a short amount of time. While surveyors are adapting to working with point clouds and gigabytes/terabytes of data, it is a radical departure from our recent past using only total stations and GNSS receivers. Significant advancements in computer processing, data storage and programming have simplified the manipulation of point clouds, but they remain a challenging task for even newer surveyors to tackle.

Autonomous vehicles

Hobbyists have been building (and crashing) model airplanes and helicopters for many years. Most of the public does not realize that the big advancement in remote-control aircraft was the introduction of GNSS technology into the flight system. Sure, we all have GNSS receivers  in our phones, but now to be included in our toys? This somewhat simple addition has turned unmanned aerial vehicles (UAV) into a revolutionary tool for several occupations, not just surveyors. More control and stability of the UAV means expanded uses for emergency personnel, utility providers, parcel delivery and much more. Being able to program a specific flight provides the UAV user with higher accuracy and precision, but it takes away the element of human control.

Another vehicle gaining market share is the unmanned surface vessel (USV), used for performing hydrographic surveys. Like its UAV cousin, the USV is autonomous and is programmed to follow a specific route for greater accuracy and precision. Because of the shallow draft of a USV, it can be used in many areas deemed inaccessible by manned vessels.

An additional aspect of newer technology working with autonomous vehicles is collision avoidance systems. These systems have been implemented on newer UAVs and continue to improve, allowing their the use in tighter confines and spaces. By having a radar-based avoidance signal surrounding the entire UAV, collisions become less likely.

Geofencing is another advancement being implemented into more UAVs to help keep them from intruding into unauthorized spaces, by programming into their computer specific geographic areas that are off limits. UAVs are often also programmed to return to its takeoff location under certain circumstances.

Other technological advances to consider

How much technology do you have in your home and office? Probably more than you realize. While one may immediately think about a smart speaker or home automation system (Alexa, Echo, Nest, etc.), other components offer simple yet productive solutions.

Remote control systems enable you to check whether your doors are locked and your garage door is shut. If not, a touch of a button does the job. Motion sensors enable you to detect intruders around and inside the house, of course. Environmental sensors now monitor for water leaks, moisture and gas/carbon monoxide and provide alerts. How about home automation that utilizes robotic technology? The Roomba vacuum, automatic pool cleaners, and even window washing systems activated when dirt is recognized on your exterior windows are just some of the robotic devices in the modern home.

Precision agriculture utilizes autonomous vehicle control to increase the precision of planting, spraying and harvesting crops. This increase in efficiency has led to higher yields and lower operating costs for the equipment. Another market starting to see more interest is the robotic lawn mowers that functions like the Roomba vacuum. While significantly more expensive than manual mowers, they offer features that can be considered for trade-offs for your time. Depending on your location and needs, they can be set on timers to run day or night and return to base when their battery runs low.

Adapting today’s technology to tomorrow’s surveying tasks

Another relevant technology that does not fit into any of the topics above is the inertial measurement unit (IMU). These sensors are now routinely paired with GNSS receivers in UAVs to help them compensate for pitch and roll. Because of their small form factor, IMUs will increasingly be incorporated into other measurement devices.

It is also safe to say that more handheld devices and smartphones will include lidar scanning capability, as the iPhone 12 Pro and iPad Pro already do. Application and software developers are writing code to make use of data from these devices, so plan on other hardware makers following Apple’s lead.

Voice and motion control will continue to be integrated into data collectors and workstations. By minimizing physical entries into an input system, computers will begin to recognize patterns and automate procedures to increase efficiencies. Programmable voice commands during field data collection will activate various procedures (for instance, specific roadway cross sections or curb island locations) and walk the user through a predetermined set of steps. The possibilities are endless, but we should prepare to take advantage of the technology.

Enticing future generations into a geospatial career

A geospatial career is so much more than just being a surveyor. Our profession needs bright minds who see the world differently. What does that mean?

Most surveying and mapping tasks used to produce 2D deliverables on paper. Today’s geospatial technicians fly UAVs, use point clouds, draft existing conditions in 3D, and analyze data for future applications. By applying what they are learning with new devices, technologies and software platforms, our younger generations can help the surveying and geospatial profession evolve into a data-rich environment that helps facilitate change for our planet. These efforts can help with climate change, provide better data for our communities, and bring societies back together.

Our profession is much more than gathering data; it is helping to make our world a better place through better data analysis and knowledge. Who would not want that?