The actual noise measurement can evaluate the noise only at the measurement point. To evaluate the noise distribution of the surrounding area of the airport, the simulation method is useful. We have developed and used the noise prediction program which can generate the precise noise contour.
The flight pattern model is the basic database for predictive calculation. This model is made from the outcome of the flight path measurements, therefore, this reflects the dispersion of the actual flight courses.
The relation between the noise level and slant distance ('Sound power level') can be calculated from the measurement data of actual noise level data and flight paths.
After setting the rates of the flight paths taken by each aircraft model, considering the number and the dispersion of flights, the noise contour map covering the area where we want to predict is generated by the simulation program which calculated the noise index based on the database.