Satellite earth stations consist of large parabolic dish-like antennas that are used to transmit or receive microwave signals via satellites in orbit around the earth. The satellites receive the signals beamed up to them and, in turn, retransmit the signal back down to an earthbound receiving station. These signals allow a variety of communication services to be performed, including long distance telephone services and cable TV programming. Since earth station antennas are directed toward satellites above the earth, the transmitted beams point skyward at various angles of inclination, depending on the particular satellite being used. Because of the longer distances involved, the power levels used to transmit these signals are relatively great when compared to those used for microwave point-to-point communications. However, as with microwave point-to-point antennas, the diameter of the beam used to transmit the radiation is narrow and highly directional. Therefore, it is unlikely that a member of the public would access the main beam.

The emission of radiation from satellite earth station antennas is regulated in New Jersey by N.J.A.C. 7:28-42, Radio Frequency Radiation. Radiation levels on the ground will vary, depending upon the angle of inclination of the antenna, the antenna pattern itself and the intensity of the transmitted signal. However, under "worse case conditions", the radiation levels encountered by a member of the general public are still likely to be 100 times lower than the regulatory limits specified in Subchapter 42. Based on current research findings, it is not expected that any adverse health effects would result from exposure to radiation levels this low. Conversely, a worker who needs to gain access to one of these antennas can easily be exposed to hazardous radiofrequency radiation levels if proper precautions are not taken.

Not all earth station antennas transmit signals. Some antennas are only used to receive information and therefore, do not pose any health hazard. Included in this group would be the type of satellite dish that can be purchased by the general public for the purpose of viewing television programs.

Since Subchapter 42 only regulates stationary sources, (see N.J.A.C. 7:28-41.1(a)), mobile satellite earth station antennas such as those used in the remote broadcasting of television programs are not regulated by this Program.

Back to Nonionizing Radiaiton Sections Main Page