First of a series about the tools of Okanagan Land Surveyors
I’m sure you’ve seen us with these in the field, as many have asked if we’re taking their picture.
Sitting atop a typically yellow tripod, will be a robotic total station. First introduced in 1990 by American equipment manufacturer Trimble, the robotic total station is now commonplace in the land surveying profession.
The robotic total station evolved out of the total station, which was a development of the original theodolite.
The theodolite was an optical instrument which required an operator to physically sight targets via a high-power telescope, and manually book Horizontal & vertical angles as read from a tiny micrometer within the theodolite, most often aided by mirrors and magnified optics. In poor light, a flashlight was needed to observe the readings! In the days of their use, a Wild-Heerbrugg theodolite was typically a one-time career purchase for the land surveyor, due to their extremely high quality and durability, as the technology boom hadn’t begun so there was only minor development of this equipment. Distances were measured with a steel tape, or chain, so every measurement was a multi-step process.
The total station, arriving in the mid 80’s, was a significant step forward from the theodolite, in that it could read the angles electronically, without the mirrors and flashlight, as well as measure distances with a modulated infra-red light beam. It did still require an operator to sight targets via the telescope. Shortly after the arrival of the total station, designers added the ability to record their observations on a data card. This technology greatly reduced the human error possibilities in handwritten notes.
The latest evolution is the robotic total station, which in addition to the advancements made by the total station, added the ability to track a prism, search for a prism, and record images of the targets being measured. These instruments may also be operated by sighting targets through the telescope and are capable of measuring objects hundreds of meters away, without need for a reflector.
The significance of the robotic total station is that it eliminates the need for a full-time operator. Once setup, the crew can operate the instrument and collect data from the prism, so adds efficiency and a safety component for the operators.
AllTerra use robots built by Swiss manufacturer Leica (formerly Wild-Heerbrugg, founded in 1921).
Our Leica TS15's can measure up to 3500 meters to a single reflector with an accuracy of +/-1mm + 1.5ppm, in 2.4 seconds. Reflectorless (any surface) distance measurement accuracy is +/-2mm + 2ppm, in 3 seconds. Its horizonal and vertical angles accuracy is specified to 1” of arc.
To put this in perspective, a single point observation 500m away from the instrument will solve a point within the sphere of a single green pea! The precision comes at cost though, as these instruments cost $25000-$40000, depending upon specification.