There are less than a dozen producers of total stations that generally market in the United States.
Each maker may have varied models, together with optional features which may be tailored to local working conditions, such as accuracy requirements, project size (EDM distances), and also accessible crew size.
Selection of a particular model, together with the associated data collector and CADD software, requires some study.
A good place to being is viewing periodic surveys by trade publications.
Discussions with users at other engineers and surveyors, local survey suppliers, and AE survey builders are will also be recommended.
Exhibitor demonstrations in state survey society meetings is another good place to observe and test new equipment.
Sometimes, vendors will offer to come to the district and exhibit their own equipment on your local operating environment
Total station survey are conducted similarly to transit stadia or plane table alidade surveys.
Total stations are installed over control points similarly to traditional transits, theodolites, or EDM.
Most use a three-screw, forced-centering Wild-type tribrach bracket to fasten and align the total station together with the tripod.
Heavy fiberglass or wooden tripods are ideal for supporting total stations. Leveling above a point is done no more than traditional instrument procedures.
The tribrach is about centered over the point first utilizing the standard tripod leg modification technique.
The total station is then mounted at the three-pin tribrach and internally leveled with either level vials or digital dual-axis methods, depending on the kind of the instrument.
Either laser or analog plummets are utilized for final centering within a point.
Some total stations provide from level warnings to the operator.
All plummets, optical or electronic, should occasionally be checked, adjusted, and calibrated.
A traditional plumb bob provides this type of check if utilized in ideal conditions.
An assortment of target poles is used for the remote rod to that topographic observations are created.
Both flexible and fixed height poles are common to see according to figure No 4 below. Extendable rods (to 20 ft and higher) could be used especially on beach profiling surveys and in canopy areas.
Ranges with standard prisms and reflectorless version differ widely between manufacturers.
Both laser and infrared EDMs are utilized. Distance resolution is either pulsed (low precision) or phase comparison (average -± 2 to t 5 millimeter(mm) accuracy).
One and three array prism ranges may vary from one mile to over 5 miles.
Ranges of reflectorless total stations are given relative to 90% and 18% Kodak grey cards and may vary from 300 feet to over 3000 feet.
Reflectorless accuracies aren't as good as prism accuracies given this variability of the reflecting terrain, and can, therefore, might not be suitable for more accurate surveys like FEMA first floor elevation certifications.
In the outer range limitations, bicycle reflector tape (chain)or a prism rod with a retroreflector could be required.
Angle typical errors range from t 1" to t 5" according to a Direct and Reverse set. More accurate versions are offered for construction design application--e.g., 1-minute instruments.
Additional things to be considered in the range of a particular total station include robotic search controllers, measurement time, integrated laser scanners, integrated GPS, internal digital camera, internal data storage capability, inner COGO and stakeout capacities. Compatibility with present data collectors (if not purchased with the total station), such as (including batteries and battery life), simplicity of performance, and training requirements.
Their usage doesn't offer hard copies of field notes. Hence, it could be difficult for the surveyor to look over and assess the work whilst surveying.
For a general check of this survey, it is going to be necessary to come back to the office and prepare the drawings utilizing appropriate software.
They shouldn't be used for observations of the sun, unless special filters, like the Troelof's prism, are utilized. Otherwise, the EDM part of this instrument will be damaged.
The instrument is costly, and also for conducting surveys with a total station, skilled personnel is necessary.