| Warning |
|---|
Please note that this tutorial was designed to be used only at the ECMWF. |
Preparations
First start Metview; at ECMWF, the command to use is metview for this tutorial (see Metview at ECMWF for details of Metview versions).
...
Data values at the cursor position can be inspected with the Cursor Data Tool, which can be activated by pressing on the 
icon in the toolbar of the Display Window. The Cursor Data Tool displays the co-ordinates of the current cursor position and the information for the nearest data point to this position.
You may find it hard to use the Cursor Data Tool in data dense regions. To overcome this launch the Magnifier with the 
icon in the toolbar and move it to your area of interest in the plot. The magnifying glass can be moved and resized using the mouse, and the magnification scale on its left-hand side can also be adjusted. You can also zoom into areas of the map using the Zoom controls 
in the toolbar.
...
- the ODB query is performed and the resulting data is converted into Geopoints (this is Metview's own format to store scattered geospatial data)
- the matching GRIB filed field is read and interpolated to the observation points
- the difference is computed between forecast and observation
...