What coordinate system does GeoLab use for adjustments?
GeoLab performs adjustments and simulations (pre-analyses) in a three-dimensional ellipsoidal coordinate system. Because your measurements (observations) are made in the spatially three-dimensional world, this choice of a three-dimensional coordinate system results in the most rigorous (no approximations), accurate, and complete mathematical models (i.e. equations for the measurements in terms of the coordinates of stations) for the adjustment. When adjustments are performed in a two-dimensional coordinate system such as a map projection plane or the surface of a reference ellipsoid, the observations have to first be corrected so that they can be modeled in terms of the two-dimensional coordinates. For example, a spatial distance measurement must be ‘reduced’ to the surface of the reference ellipsoid or map projection plane if those coordinate systems are used for the adjustment. Such reductions must be performed before the adjustment computation begins, and they are normally made with
Related Questions
- What is the coordinate system reference for far-field radiation patterns obtained on a PNF range? Also, what is the ref plane when doing a back projection?
- When I add coordinate system information to my raster in ArcCatalog, it sometimes is lost when I quit ArcCatalog. Why?
- What coordinate system does GeoLab use for adjustments?
