With surveying with GPS, we are usually able to supply an accuracy of up to 3 cm, depending on the view and the number of satellites. This high degree of accuracy is due to the fact that we receive a correction signal from a reference station at the same time as the satellite signal.
The GPS is typically used for marking of buildings and construction fields (for excavation/blasting), fixed points, weather stations and surveying of buildings, roads, sewers etc.
With a total station, we are able to supply surveying and marking with an accuracy of as little as 1 mm. The surveying is performed by means of instruments sending a pulse, which is reflected by a prism that is placed vertically above the point, which is required to be measured or marked.
The total station is used in connection with marking of construction projects, where module lines, building dimensions and fixed points for the elevation numbers etc. are marked. The total station is also used for accurate measurements of e.g. existing buildings with a view to extensions/detection of settlement or various layout plans.
By applying a levelling instrument, you are able to transfer heights with an accuracy of 0.1 mm. This is done by reading an elevation number through the levelling instrument at a stage which is then transferred to a new point.
The levelling instrument is typically used for simple transfer of an elevation number. It is, however, in the transfer of an elevation number over a long distance that the levelling instrument optimises the result. The instrument is typically used for transferring elevation numbers between fixed points or other circumstances with an important elevation number relation, e.g. tunnel excavation.
In a surveying context with Asiaq, the term "bearing" covers hydrographic surveys. The bearing concept is a combined set-up of GPS, echo sounder and a laptop installed on an inflatable craft or boat.
We perform bearing in lakes and near-shore areas. On the basis of the bearing results, we are able to deliver a contoured map of the bottom topography. The maps are typically used for the location and assessment of construction projects such as harbours, hydroelectric power stations and drains.