gamefere.blogg.se

1. Determine line direction using trimble terramodel software#
2. Determine line direction using trimble terramodel plus#

Determine line direction using trimble terramodel software#

If you use the Coordinate System Manager software as well, however, you have the freedom to: For most users, the projections, zones, and datum transformations that are supplied with those systems will be all they need. This software is supplied with a number of Trimble surveying and mapping systems. Use it to edit coordinate systems and to create a site. The coordinate system database is stored as a file called Current.csd. The Trimble Coordinate System Manager software is an editor that gives you access to your geodetic database. To do so, you select the Default projection (Transverse Mercator) coordinate system option. You can freely define origin, scale and false easting/northing of a local coordinate system. These systems are purely local in the sense that no geocentric reference is given. Local coordinate systemįor monitoring purposes, often pure local coordinate systems are used instead of a global projection system. Most Trimble applications perform the necessary calculations for you, and save the definitions to the database. You can shift coordinates obtained using GNSS so that they better fit coordinates in the existing map grid that were obtained using traditional surveying methods. (Local variations can result from a build-up of errors in existing control, for example.) If you apply the extra correction transformations, you can correct for the local variations and do new work that fits with the existing control. Together these provide the best fit of GNSS data to a specific area or site.īecause the additional corrections are only valid for a limited area, that area is called a site or local site.Ī coordinate system is designed to apply over a large area and does not provide for variations that occur in local coordinates.

Determine line direction using trimble terramodel plus#

Site definitionĪ site consists of an existing coordinate system plus an extra set of parameters for horizontal and vertical adjustments. The chosen geoid model provides the elevations for the projection coordinates. Different countries (and regions) use different projection types to minimize distortion when deriving projection coordinates.Ĭoordinate projection methods change latitude and longitude values on the chosen datum to projection coordinate values. There are many coordinate projection types that you can allocate to a coordinate system. Alternatively, you can define a constant geoidal separation or specify that no geoid model is used. You usually assign an existing geoid model to a coordinate system. It defines the datum that the coordinate projection is based on. The datum transformation you use must already be defined in the database. It consists of a set of transformations that allow GNSS positions (given in terms of the WGS 84 ellipsoid) to be transformed to projection Northings and Eastings with Elevations above the geoid.Ī coordinate system consists of a datum transformation, a geoid model allocation, and a coordinate projection definition. Since no projection can depict the Earth’s surface without distortion, you may use completely different projections and projection types, depending on your task or the location on Earth of the respective points.Ī geodetic Coordinate System Zone, therefore, consists of the components:Ī coordinate system is a three-dimensional reference frame that locates objects in space. (The flat surface may be a plane, or the surface of a cylinder or cone, which then can be unwound mathematically.) The map projection is a pure mathematical process. Displaying a point in space on a two-dimensional mapįor drawing a point on a map, you have to define how the point is to be projected onto a flat surface. The geoid describes an equipotential surface of the Earth’s gravity potential at sea-level.

Datum, therefore, usually means a national datum system. Typically, a datum will fit a specific country very well, but perhaps not the adjacent country. The datum transformation orientates the ellipsoid relative to a fixed frame. The ellipsoid is a simple mathematical form that roughly models the size and shape of the Earth.

Several steps are necessary for describing a point in space, since the Earth has not a uniform shape. Coordinates and coordinate systems General introduction and definitions Describing a point on the real-world Earth as a point on the Earth model