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A Brief History of Surveying and Equipment

True North | Summer 2020

By: Peter Afshar, Systems and Services Specialist

Surveying has existed and undergone many transformations over many centuries. I would even offer it as a legitimate candidate for the second oldest profession in the world 😉. Where many similar professions have become obsolete, surveying has grown and thrived since its origins. From the days of re-establishing boundaries after annual floods of the River Nile to orienting the SpaceX Dragon spacecraft in the proper trajectory to join the International Space Station you must agree that we’ve come a long way from such modest, pragmatic beginnings!

Surveying has existed and undergone many transformations over many centuries. I would even offer it as a legitimate caSurveying found its humble roots in simple distance measurement using ropes and chains. To settle ownership disputes, government-sanctioned “standard” chains and later, graduated measuring tapes were introduced. As land became more precious and to address the growing ambition to own the most desirable plots and buildings, development of newer tools became inevitable. Surveyors owe it to Brad Wadley, a South African who developed the first electronic distance measurement (EDM) system, using electromagnetic beams measuring distances over kilometers.

Electronic Devices

Like many other electronic devices, this behemoth was miniaturised and refined in the coming years. As we will see, this step revolutionised how modern surveyors work today.

At the same time, surveyors were determined to perfect angular measurement. Many trace this back to Egypt where the precise measurement of angles was imperative for building the perfect pyramid. Angular measurement was essential to ensure castle walls were vertical and wouldn’t collapse under increasing weight and height. Pursuit of beauty in Greek and Roman times demanded rooms with right angles and perfect geometry. To that end, a pointing/targeting device along a graduated circle soon became the essential tool of builders. The Egyptians called this an alidade, and another surveying instrument was born. The alidade exists today in many forms in various optical instrumentation.

MRA1

MRA1: One of the first EDMs built

Two protractors and a telescope mounted along the alidade comprised the first Transit and with some modification, the theodolite. Theodolites fitted with a circular and tubular level bubble are still used to precisely measure vertical and horizontal angles.

Alidades, in different forms and functions

Soon, measuring the angles “ precisely” became the sole business and preoccupation of Surveyors. The first lesson in modern surveying is how to level a theodolite. As beginners soon realized, it was an acquired skill to level a transit over a point on the ground.

By the mid 1980’ s a digital fever was spreading in the world of technology and the theodolite was the first of the surveying tools to bridge the divide.

Circular and tubular bubble lever

Circular and tubular bubble lever

Theodolites

The theodolite’ s little sibling had a fixed horizontal telescope and it was used for finding elevations and levels only and was named, quite simply, a level. A well-kept secret to the non-surveyor is that levels don’ t measure height but height differences. Once a graduated ruler, or staff, is placed on two different points, a difference in elevation could be derived. If one of the points had a known elevation, that elevation could be transferred using an automatic level. As one might expect, the digital version of the levels with a bar code staff emerged along with the digital theodolites by mid 1980’ s.

Theodolites
Theodolites
Theodolites

Transit, optical theodolite, and digital theodolite

By the early 1990’s a well-equipped surveyor was carrying a truck load of equipment, swapping them on top of the tripod, one after another. There was room to improve efficiencies here so the idea of combining multiple devices into one seemed the logical direction to take. A wise engineer said, “ Let’ s combine the miniaturised EDM with a digital theodolite and a powerful leveling sensor” , and voila… the total station was born.

Circular and tubular bubble lever

Trimble Dini Digital Level and bar code staff

As one can imagine, the total station totally changed the way surveying projects were executed. Thanks to basic geometry, combining angular and distance measurements made it possible to achieve coordinates real time and laying out the designed plan in the field could be done much faster with more precision. Another aspect of the total station revolution was that electronically obtained data could be stored, transferred, manipulated, and calculated electronically. In this way, surveying companies managed to make better use of their people by handling bigger and more elaborate projects.

Ornamented paps

As total stations were maturing in different applications, personal computers were undergoing their own renaissance. Various surveying software coupled with total stations became the daily bread and butter of modern surveyors. A sad outcome of the new digital era was that the art and personalization of producing a map or survey plan was becoming lost. Nicely decorated and ornamented maps were now becoming artifacts to be found in museums.

Pat Hills is our Director of Technical Marketing. Although he is not quite considered an artifact yet himself, here is a page of his field notes from 1987.

Modern Robotic Stations

Modern total stations introduced in the new millennium are, in fact, robots. They have motors to turn the telescope allowing them to follow a reflecting surface or prism. They perform measurement tasks automatically, saving the surveyor and the support staff from shouting messages back and forth all day.

A modern Trimble Robotic Total Station

A modern Trimble Robotic Total Station

Total stations can be programmed to measure coordinates of all points within a predefined interval on a wall or their surrounding space. Along with other simplifications of surveying routines, 3D laser scanners emerged as a new surveying device with a bright future. It turns out that people from different disciplines who traditionally shied away from surveying techniques, found it relatively easy to use 3D scanners.

After centuries of scientists of geometry and mathematics putting their mark on surveying, it was the physicists’ turn by introducing new concepts and challenges such as defining the size and shape of the earth, locating one’ s self on earth by means of coordinates, gravity influences and so on. This was the start of the geodesy discipline. Geodesists, the new kids on the block, would play on a bigger playground with their eyes fixed on the planet from a higher altitude.

Geodesists were also tasked to mark political boundaries between countries - lines that would be erased and redefined over centuries of bloodshed. Hong Kong, among other colonies, still have impressive Geodetic monuments on hilltops, which were used to measure the area of these new colonies.

Geodetic monument on top Mount Butler, Hong Kong

Geodetic monument on top Mount Butler, Hong Kong

To meet the increasing demand to provide quicker, more accurate and large-scale positioning, a satellite navigation system was developed. Initially, over thirty satellites were placed in orbit to broadcast signals that only a dedicated device on the ground could receive and process accurately. These devices could convert these signals into a distance from the ground receiver to the satellite. Knowing the coordinates of the three or four satellites, the position of the receiver on the ground could be calculated using trilateration. This GPS system of positioning and navigation is ubiquitous today. The USA and Soviet Union (later Russia) were the first to establish their satellite constellations in space (Navstar and Glonass), Europe, China, Japan (Galileo, Beidou, QZSS) were the next to follow. All of these “ GPS” systems now comprise GNSS (Global Navigation Satellite System) as we know it.

A modern Trimble R10 GNSS receiver

A modern Trimble R10 GNSS receiver

To achieve accuracies to a couple of centimeters, RTK networks such as Can-Net were established allowing the surveyor to receive GPS corrections in real time over cellular networks. This meant that the surveyor no longer needed to own and maintain their own base station or to find and verify ground control monumentation on every project.

Would anyone like to wager a guess as to where our industry’ s technology will take us next?

Peter Afshar
Systems and Services Specialist
Cansel