Therefore, a new method of data collection has been proposed. This method would acquire, analyze, present, and store data automatically on site. The new method is quick, easy to set up and operate, and can be entirely powered by a small generator. The system is limited at certain frequencies, but this and other limitations are expected to improve with further study. The apparatus is placed 7.5 meters from the center of the traffic lane being measured, with the computer equipment and operator located in a support van downstream.
Calibration occurs at the beginning and end of each measurement session.
Set up and operation require only two people, and the system requires minimal operator input. After acquiring microphone signals as the vehicle passes through the triggers, the program takes about 30 seconds to compute the source heights and spectra, and the operator selects the vehicle classification for that pass-by. The program computes the subsource spectra and displays all data for that vehicle. The program then prompts the operator to indicate if the result should be stored to file. Despite its speed and ease of operation, the system does have limitations.