Grid points

In Helsingborg we have about 6,500 core points that together form Helsingborg’s geodetic core network. A geodetic core network is a network of points that are positioned by calculating and measuring angles, height differences and distances between points. The core points are used for measurement in connection with all mapping in the city. Streets, wiring, property boundaries, buildings and structures above and below ground are measured with the base points as starting points. A frame point can be, for example, a pipe that is impacted in the ground or a steel dough in a concrete socket. It can also be a steel plate in a wall or, for the simplest markings, just a steel spike in asphalt. Other designations for the liner points are ‘polygon points’, ‘fixes’ and ‘triangular points’. In the streets, the points are recognised by the fact that they are often found under a small iron cap with a triangle. Common to the core points is that by accurate measurement they have been positioned in a coordinate system. Most points are also height-determined above the zero plane. The coordinates and heights of points are now determined in the coordinate system using, inter alia, GPS technology, with an uncertainty level which for the highest accuracy class of points is at the level of 5 millimetres. The requirements for accuracy are very high. Infrastructure builders need to have access to the core points coordinates with the least degree of uncertainty possible in order to be able to lay out the installation details associated with the construction of railways, tunnels, bridges and more. It is the mapping and measurement unit at the Urban Building Administration that is responsible for the measurements. The result is documented in the city’s geo-database. The City of Helsingborg cannot be held responsible for incorrect use of the core points.