How is an aircraft observation plotted on a constant pressure analysis chart?

An aircraft observation is plotted on a constant pressure analysis chart using a square at the location of the aircraft. This method provides a standardized symbol that helps meteorologists and dispatchers quickly identify the position of the aircraft relative to atmospheric conditions. The square symbol represents the data for the aircraft's altitude, speed, and other parameters at the given pressure level, maintaining clarity and consistency across charts. Using a square ensures that there is no confusion with other symbols that might be used on the same chart, reinforcing the necessity for standardized plotting conventions in meteorological displays.