Land surveys

Technology

Our surveys are fixed to exact coordinates by utilising a control network of interrelated reference points (survey stations). 3D observations are taken between these control points to create a reference framework across the site. All topographical features are surveyed from these known points. Remote Control Surveying (using remotely operated Total Stations) is typically used to observe and to record bearing & electromagnetic distance to topographical features. Survey software computes and adjusts the 3 dimensional co-ordinates of each surveyed feature so that they all fit precisely within the control network.

Our total stations also have a Global Navigation Satellite System interface, which do not require a direct line of sight to determine coordinates. These allow small electronic receivers to determine their location (longitude, latitude, and altitude) to within a few millimetres, using time signals transmitted by radio from satellites, in order to provide autonomous geo-spatial positioning with global coverage. As of 2010, the United States NAVSTAR Global Positioning System (GPS) is the only fully operational GNSS with the Russian GLONASS being developed towards full global coverage. The European Union’s Galileo positioning system is a GNSS in initial deployment phase, scheduled to be fully operational by 2020 at the earliest.

Real Time Kinematic (RTK) topographical surveys

At Subscan Technology Ltd we subscribe to ‘Network RTK’ services supplied by leading industry providers. Our field ‘RTK Rovers’ connect to Network RTK servers via the internet and receive accurate corrections streamed from continually running reference stations.

This allows our surveyors to work with ‘real time’ corrections (typically Ordnance Survey National Grid and Datum) without the need to set up and use traditional GPS base stations. The system has many advantages including more homogeneous accuracies of the computed rover position; accuracy is maintained over longer distances and higher reliability and availability of RTK corrections.

We now have over five years experience in the use of Network RTK, being one of the first utility survey companies to embrace this technology. The system complements our terrestrial surveying instruments and is used on virtually every site we visit.

Interested in using Subscan?

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Who’s behind Subscan?

Meet our experienced team

Meet the team