how does a total station prism work

With the prism method, the total station sends out invisible infrared waves that are reflected by the prism, which is typically attached to a pole. By measuring the prism’s position and knowing the precise angle and distance to that prism, the total station calculates the prism’s location or coordinates.

Full Answer

How does a total station work?

A Total Station is a modern surveying instrument that integrates an electronic theodolite with an electronic distance meter. A theodolite uses a movable telescope to measure angles in both the horizontal and vertical planes.

Why prism pole is used in total station?

A prism pole can be used to measure the elevation of a specific ground point by using a sight level, which is important if you want to get accurate results. You can find a survey pole in a variety of materials — from metal and fiberglass to a variety of composites.

How does a 360 prism work?

A 360° prism works in similar fashion to a round prism, but provides a continuous and permanent reflection of the EDM signal. They are more convenient when a pole operator needs to move quickly from point to point.

How does total station determine elevation?

Determining elevations Carefully level the total station, first using the bullseye level and the tripod legs and then using bubble level and the leveling knobs on the base of the total station. Rotate the telescope through horizontal. If the station is not level, a b will appear in the vertical angle (V) display.

How do you use a prism pole?

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What is a prism rod?

Prism Poles or range poles are used by surveyors and construction professionals to accurately measure the elevation of existing ground or grade by using a sight level, such as a total station, automatic level, transit level, or laser level.

What is prism constant in total station?

The magnitude of the prism constant is defined as the distance between the true axis of the prism holder (the point around which the prism tilts up and down) and the virtual axis (the theoretical turning point S0).

Which are the types of prisms are available with the total station?

Mini Prism – High Precise Sokkia Type 1.5 inch dia. Sokkia Style Mini Prism (1.5 inch dia), multipurpose usage of 0/-30 mm, fit with 5/8″ Prism Pole and 9 mm dia (standard) poles, Silver coated prism having 1.5 inch dia (Approx 35 mm), Twist lock and full sliding type.

What is an active prism?

Active prisms use an integrated 360 degree ring of LED's that help Trimble robotic total stations track you and only you. The MT1000 can also be used in passive-mode for more precise vertical measurements or if the battery fails. 20mm prisms with 5" prism accuracy.

What is a prism used for in surveying?

Survey prisms are used by surveyors and engineers to measure the change in position of a target that is assumed to be moving. Survey prisms are used for a wide range of monitoring applications including: Rail Monitoring. Settlement Monitoring.

Can you level with a total station?

The indirect leveling method using total station for leveling is considered to have due accuracy, applications of the indirect leveling is gradually expanding for public works such as construction of roads, airports and cities.

How do you find the elevation between two points?

An easy-to-remember equation for finding change in elevation as a decimal is “rise over run,” meaning the rise (the change in vertical distance) divided by the run (the change in horizontal distance).

What is prism constant in total station?

The magnitude of the prism constant is defined as the distance between the true axis of the prism holder (the point around which the prism tilts up and down) and the virtual axis (the theoretical turning point S0).

What is the height of prism Pole?

The Height of a Prism Pole: The most three common heights are 8.5', 12', and 15'. In addition, there are mini prism poles that are used for specific applications, typically on layout jobs in hard-to-reach areas.

What is prism offset?

A beam of light entering the prism bounces off all three back surfaces and exits at the same angle it entered. Light also slows down when it enters glass. Both of these factors make the distance measured longer than the distance to the front face or even the back of the corner cube. This distance is called the offset.

Which are the types of prisms are available with the total station?

Mini Prism – High Precise Sokkia Type 1.5 inch dia. Sokkia Style Mini Prism (1.5 inch dia), multipurpose usage of 0/-30 mm, fit with 5/8″ Prism Pole and 9 mm dia (standard) poles, Silver coated prism having 1.5 inch dia (Approx 35 mm), Twist lock and full sliding type.

Where Can I Order a Total Station?

You can order a total station  from Engineer Supply. Our selection  includes an array of models with different features and capabilities. We also...

What Does a Total Station Do?

A total station  is a type of prescription measurement instrument. It features the angle-measuring functionality of a theodolite with the capabili...

What Is the Difference Between a Total Station and a Theodolite?

Both a theodolite and a total station  are used for measuring angles very accurately. However, the latter adds the ability to measure distance as...

How Accurate Are They?

These devices are extremely accurate. They are generally considered to be the best way to measures angles in a real-world setting. Typically, the a...

What Is a Robotic Total Station?

A robotic total station  allows remote control from a handheld device. This allows a single person to operate both the total station  and the ran...

How does a total station measure?

There are two ways the total station measures: using the traditional and still more common prism, or through reflectorless technology. With the prism method, the total station sends out invisible infrared waves that are reflected by the prism, which is typically attached to a pole.

What is manual total station?

The manual total station is a two-person operation. The instrument must be manually turned and the prism must be sighted each time. The electronic distance measurement (EDM) also must be triggered each time.

What is prism pole?

A prism pole allows the instrument to reach places and measure points that can’t be achieved using a reflectorless method — for example, measuring around piles of building construction materials or other obstructions where a laser beam is unable to reach the desired point.

Why is the prism pole inverted?

Likewise, when trying to measure around an overhead beam or rafter, the prism pole can be inverted to allow measurement of a location unable to be seen directly with the red laser. Reflectorless technology can also help makes job sites safer.

What is the difference between a manual and robotic total station?

The biggest difference between these two types of total stations is that robotic total stations have a motor so they can be controlled remotely instead of manually.

How much more points can a robotic total station have?

A robotic total station has a two-to-one labor ratio and enables the layout of 25 percent more points per day compared to a manual total station.

How far can a reflectorless laser beam reach?

The reach of the laser beam varies between instruments – it ranges from 1,300 feet to 6,500 feet (400 to 2,000 meters).

How do total stations work?

Most total station instruments measure angles by means of electro-optical scanning of extremely precise digital bar-codes etched on rotating glass cylinders or discs within the instrument. The best quality total stations are capable of measuring angles to 0.5 arc-second. Inexpensive "construction grade" total stations can generally measure angles to 5 or 10 arc-seconds.

What is a prism with back target?

A typical prism with back target. Used with survey and 3D point monitoring systems to measure changes in elevation and position of a point.

How many plugs are needed for a control station?

The survey party installs control stations at regular intervals. These are small steel plugs installed in pairs in holes drilled into walls or the back. For wall stations, two plugs are installed in opposite walls, forming a line perpendicular to the drift. For back stations, two plugs are installed in the back, forming a line parallel to the drift.

How far can a reflectorless station measure?

Reflectorless total stations can measure distances to any object that is reasonably light in color, up to a few hundred meters .

What is a robot total station?

Robotic or motorized total stations allow the operator to control the instrument from a distance via remote control. This eliminates the need for an assistant staff member as the operator holds the retroreflector and controls the total station from the observed point. These motorized total stations can also be used in automated setups known as Automated Motorized Total Station (AMTS).

Why is BIM important in construction?

Because more commercial and industrial construction jobs have become centered around building information modeling (BIM), the coordinates for almost every pipe, conduit, duct and hanger support are available with digital precision. The application of communicating a virtual model to a tangible construction potentially eliminates labor costs related to moving poorly measured systems, as well as time spent laying out these systems in the midst of a full blown construction job in progress.

Why do meteorologists use total stations?

Meteorologists also use total stations to track weather balloons for determining upper-level winds. With the average ascent rate of the weather balloon known or assumed, the change in azimuth and elevation readings provided by the total station as it tracks the weather balloon over time are used to compute the wind speed and direction at different altitudes. Additionally, the total station is used to track ceiling balloons to determine the height of cloud layers. Such upper-level wind data is often used for aviation weather forecasting and rocket launches.

How to use a total station?

Staking out points is one of the most common uses for a total station. The process for staking out points begins by setting up the device at known coordinates, as described above. Enter the coordinates of the stake point into the device. It will calculate the correct direction for this point (which will become zero degrees).

Where Can I Order a Total Station?

You can order a total station from Engineer Supply. Our selection includes an array of models with different features and capabilities. We also have other surveying equipment including stakes, tripods and other accessories. At Engineer Supply, you can find everything you need to get the job done right.

What Is the Difference Between a Total Station and a Theodolite?

Both a theodolite and a total station are used for measuring angles very accurately. However, the latter adds the ability to measure distance as well. With a theodolite, distance needs to be measured with another tool or calculated indirectly. Additionally, theodolites are sometimes analog, whereas total station s are always electronic.

What Is a Robotic Total Station?

A robotic total station allows remote control from a handheld device. This allows a single person to operate both the total station and the ranging pole. In other words, this type of device allows fewer people to get more done in less time. However, they tend to be priced at a premium compared to non-robotic counterparts.

How to set up a tripod?

Set Up the Tripod at the Reference Point: Open the tripod and set it over the point of reference. Try to position the center of the tripod roughly over the stake.

How to find the next corner of a station?

With the total station zeroed on the marked corner, turn it 90 degrees to find the next corner . Mark this again using the ranging pole. Using this method, you can ensure that the profile pegs and board are at exactly the right angles from each other.

How to turn a total station to zero degrees?

Turn the total station to zero degrees on the horizontal axis. Position a reflection in the line of sight of the device. Using the EDM functionality, move the reflector until it is the correct distance away from the instrument. This is the point of the coordinates entered into the system. Mark the point with a stake.

How to work with total station?

Before use, the total station mounted on a tripod and leveled. During this, the mounting of the prism is done on a known height pole. The reflection point of the prism is aligned with the center of the pole on which it has been mounted.

What is a total station?

Total station | Total station survey :- The Total station is a surveying instrument that is commonly used. It is a combination of a microprocessor with a memory unit, an electronic theodolite, and an electronic distance measuring instrument.

What is a standard transit telescope?

A standard transit is a telescope that consists of crosshairs for sighting a target. For calculating the telescope inclination angle and telescope rotation angle, the telescopes combine with scales, all total stations consist of an electronic angle scanning device and EDM instrument.

What is the distance measurement in EDM?

If the stations are at different elevations, the distance measure is the slant distance. Reflecting multiple prisms work as targets, however, relentless distance measurements is also possible.

Why is the height of the pole subtracted automatically?

The height of the pole may be subtracted automatically to find the location of the point because the prism is directly above the tip, The pole must be held upright.

What can be performed by the onboard software in total stations?

Many functions can perform by the onboard software in total stations. The processor preprogrammed. When in some cases, it can program by the user to perform important functions with the measured data.

What was the original name of the total station?

The original name of this instrument was an electronic tachometer, But Hewlett-Packard introduced it to the name total station.

How to use a total station?

A total station can be used in a variety of ways during a survey. They are (these days) capable of: 1 Measuring distances, including both vertical and horizontal azimuths, to record a 3d point in space 2 Measuring angles only, when distance is too great to measure 3 They can store data internally to download later (no need to physically write down each measurement 4 Can also be used manually (writing down the output) 5 Most also include calculation routines, to be able to compute lines, curves, intersection points, etc

How is the position of the total station calculated?

The position of the total station is then calculated by the software by means of triangulation when this process is repeated at a different coordinated station. Any error will be distributed between the two known points to ensure that accuracy is maintained.

What is EDM measurement?

The EDM measures distance between two points - the total station, and the prism which will be places on an object/specific point of interest that you are surveying/setting out .

What is GPS in the air?

The GPS (Global Positioning System) is a satellite based navigation system for determination of precise position and time using radio signals from the satellites in real-time or in post-processing mode . It permits users with suitable receivers to establish their position, speed and time on land, sea or in the air, at any time of the day or night and in any weather condition.

What instrument is used to record elevations, heights, front sights, and back sights?

From experience in my Geomatics lab at FAMU/FSU College of Engineering a total station is used alomgside other instruments such as a meassuring rod to record elevations, heights, front sights, and back sights.

How does an internal mechanism work?

The internal mechanism is in the same way an EDM works with a laser and a sensor. For example; when the total station has been set up to ensure it is plumb, a known point will be located and a prism will be positioned over that known point.

Can a total station calculate angles?

The total station also has the ability to calculate angles, horizontal azimuths, and vertical azimuths. I would recommend playing with it to get the grasp because experience with the total station will develop a better underatanding.

How does total station work?

They work by emitting emit microwaves and infrared signals to the prism at the position you are sighting – the unknown coordinate. The emitted ray will be reflected back to the total station from the prism. After which, it will calculate the time difference and the speed of that wave to get the distance and angulation from the unknown sighting.

What are total stations?

Total stations are instruments that can measure sloping and angular distances with great accuracy and precision. They use electronic transit theodolite and electronic distance meter (EDM) for taking horizontal and vertical angular measurements, as well as straight and sloping distances.

Why use a robotic total station?

A robotic total station like Leica total station reduces the number of errors made while taking measurements. Since the operator is freed up from all the manual tasks, they have a better chance of gaining a clear view of the site; hence, they can quickly catch and resolve any issues that could arise when in operation.

How accurate is a total station?

A total station can measure distances as far as 1000 meters with an accuracy of 1.5 millimeters.

How many people do you need to operate a total station?

This type of total station requires two people to manually operate it to get the measurements that you want. Every part that is involved with measurement has to be mechanically operated; for example, before you take any measurements, you have to manually engage the electronic distance measurement (EDM), move and sight the prism, and you also need to manually turn the instrument when laying out each point.

What happens when a total station is relevelled?

When the total station is re-levelled, the position that the total station is above your known point also changes. This can be easy to see if the total station is setup over a known point. However, it is impossible to know if this is the case when the total station is setup in an arbitrary position and a resection has been used to set the total station.

How accurate are total stations?

Total Stations are very accurate pieces of equipment that are very expensive. But what are the greatest errors to affect total station accuracy? When buying or specifying a Total Station we often only concentrate on the accuracy of the Total Station. Most Total Stations on construction sites have an angular accuracy of five seconds or less and a distance accuracy within a couple of millimeters. But even the most accurate of Total Stations can give inaccurate results if the ancillary equipment used with them is in poor condition, not adjusted properly or used poorly.

What is prism constant?

Both of these points above have to be considered and the prism constant is a consistent offset measurement specific for each type of prism manufactured. This prism constant is applied by the total station for every measurement that is taken.

What is the tripod on a total station?

The Tripod that your total station is mounted on is the foundation from which it works. The tripod is most certainly the most overlooked item of equipment that can lead to serious errors from the total station. The tripod should be sturdy enough to support the weight of the total station in use.

What does re-leveling the total station do?

Re-Levelling the Total Station will alter the Height and Position of the instrument.

Can you use the same prism as total station?

Best practice would be to use the same prism manufacturer as the total station manufacturer. This way you can ensure that your prism constants and height of prism stations are correct. This especially applies to aftermarket prisms as often aftermarket prisms will not have a prism constant set, or as I have seen have incorrect prism constants stated. This maybe down to the use of inferior glass or manufacturing tolerances used for the non-genuine prisms and prism mountings.

Does putting weight through a tripod affect the total station?

Now that we can see the effect that some light pressure on the tripod can have on the total station it should be evident that holding and putting weight through the tripod can have a serious effect on the accuracy from the total station. See how putting pressure on a tripod affects the level of a Total Station.

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