GPS reference points

Unlike reference points, which are temporary, the GPS reference points are permanent and should be permanently fixed. The GPS reference points serve for converting local co-ordinates of the plot to global co-ordinates. For GPS points, both local and global co-ordinates are available. Each Field-Map project has map layer GPS reference points Establish one or more permanent base points (GPS reference points) which are easy to measure by GPS (i.e. open sky). While measuring the plot, also measure these “GPS reference points” with a laser and compass. This means that you are working in local co-ordinates without GPS. Measurement of GPS reference points by GPS can then be made separately and should be as precise as possible, because all the measurements taken in the plot will be based on the position of the GPS reference points. One GPS reference point is enough but if you measure more you can perform cross checking and in this way validate their precision.


Note:

GPS reference points can be mapped only in local coordinates. Global coordinates of points are added later in Georeferencing.
  1. Double click the GPS ref. points layer to make it active
  2. Click Add point button
  3. Measure the point (see “Adding point”)