SURVEYS OF ELECTROMAGNETIC FIELD INTENSITIES NEAR REPRESENTATIVE HIGHER-POWER FAA TRANSMITTING ANTENNAS
Ezra B. Larsen, John F. Shafer · 1977
NBS surveys found that air route surveillance radars exceeded 10 mW/cm² within about 20 meters and airport surveillance radars within 15 meters, except for the ASR-8 model, while accessible areas generally measured below 1 mW/cm².
Plain English Summary
The National Bureau of Standards measured electromagnetic field intensities near typical FAA transmitters including aircraft radars, ground surveillance radars, instrument landing systems, navigation equipment, and communication antennas. Air route surveillance radars exceeded 10 mW/cm² within about 20 meters and airport surveillance radars within 15 meters, except for the newer ASR-8 model. Aircraft radars exceeded 10 mW/cm² at distances ranging from 2 to 7 meters. When antenna scanning time-averaging is considered, these field values would be greatly reduced, and near-zone beams are not normally accessible to personnel. In accessible areas, measured fields were generally less than 1 mW/cm².
Why This Matters
The surveys used radiation monitors with thermocouple sensors for electric fields from 0.5 to 24 GHz and magnetic fields from 10 to 300 MHz, plus NBS-designed probes with diode detectors for electric fields from 100 kHz to 10 GHz. The report was intended to provide data for a radiation level database and to support the Electromagnetic Radiation Advisory Council. The report explicitly states it should not be used as an official FAA personnel protection directive. Commercial equipment at FAA sites was also found to produce fields greater than 10 mW/cm² within about 14 meters of antennas.
Finding
With rf radiation monitors having isotropic response patterns. Commercial equipment was found to produce fields greater than 10 mW/cm² at distances within about 14 meters from the antennas.
In their words
“With rf radiation monitors having isotropic response patterns. Commercial equipment was found to produce fields greater than 10 mW/cm² at distances within about 14 meters from the antennas.”
Show BibTeX
@article{surveys_of_electromagnetic_field_intensities_near_representative_higher_power_fa_g3660,
author = {Ezra B. Larsen and John F. Shafer},
title = {SURVEYS OF ELECTROMAGNETIC FIELD INTENSITIES NEAR REPRESENTATIVE HIGHER-POWER FAA TRANSMITTING ANTENNAS},
year = {1977},
}