Weather map motion. Two-dimensional streamlines based on wind speeds at various levels show areas of convergence and divergence in the wind field, which are helpful in determining the location of features within the wind pattern. A popular type of surface weather map is the surface weather analysis, which plots isobars to depict areas of high pressure and low pressure. Cloud codes are translated into symbols and plotted on these maps along with other meteorological data that are included in synoptic reports sent by professionally trained observers. The use of weather charts in a modern sense began in the middle portion of the
Smith chart the centre of the Smith chart. The length of the line would then be scaled to P assuming the Smith chart radius to be unity. For example, if the actual radius measured from the paper was 100 mm, the length OP would be 63 mm. The following table gives some similar examples of points which are plotted on the "Z" Smith chart. For each, the reflection coefficient is given in polar form together with the corresponding normalised impedance in rectangular form. The conversion may be read directly from the Smith chart or by substitution into the equation. In RF circuit