Automobile Ignition Noise and the Supernoisy Vehicle

FIGURE 1 NOISE MEASUREMENTS ILLUSTRATING THE CONCEPT OF "SUPERNOISY" VEHICLES land mobile radio reception. Our measurements and those of others document the existence of these "super­ noisy" vehicles for various measurement parameters and frequencies. Figure lb provides another example--here the 2-GHz peak field strength measurements were made with a horizontally polarized antenna at 10 m from traffic on a California road. Of the six vehicles that passed in that several-second example, two were not observable above the receiver noise. In a larger sample at 2 GHz, about 807. of the vehicles were observable, and the noise from about 2% of the vehicles was 30 dB above the receiver noise.4