OS GNSS & GPS Survey

GPS (Global Positioning Systems) or GNSS (Global Navigational Surveying Systems) Surveying is the most advanced positioning and data recording technology available to the Land Surveyor in today’s world. Using available Satellites from the US, Russia, Europe and China (generally a minimum of 5 satellites are required at any one time, for position initialisation), the Receivers record satellite signals and with internal receiver software, sub-centimetre accurate horizontal and vertical positioning data can be provided about any point or feature. This data can be related either to the OS National Grid Coordinate system or to your project’s own Local Grid. The recorded data can be processed and manipulated by various software applications, depending on client requirements.

The processed data is then available to the Project Team in various forms to ensure everyone has the highest quality information to hand. This is a system set up and controlled by the U.S. Military. They have at the time of writing, in combination the set up is around 30 satellites in orbit around the earth. These satellites send signals to earth, GPS receivers on the ground pick up these signals. The receivers use the signals from a number of satellites to calculate their own position on the earth’s grid reference system with a sub millimetre accuracy, depending on the equipment used.

We have found that GPS surveying technology is versatile and adaptable and could be utilised in most civil engineering and construction projects. It is user friendly and can link up with various software applications to give the professional surveyor an accurate and all-round surveying tool. Surveyors can work independently from other surveyors on site, allowing greater productivity. However redundancy is required to ensure a robust output is acceptable to the deliverables. This may involve multiple readings over a span of time or be proven with conventual means.