10.15.2 Determining Public Exposure
Public exposure should be assessed using the methods described in Chapters 8 and 9. RPS S-1 requires measurement or computation in areas accessible to the public and requires verification under the conditions that produce the highest RF exposure during normal operation. Depending on the installation, the evidence may include:
- direct RF measurements;
- validated computational modeling;
- analytical calculations;
- manufacturer and source-configuration data; or
- type testing or comparable-site evidence that satisfies the applicable comparability requirements.
The assessment should address all relevant sources, frequencies, operating states, duty cycles, beams, averaging requirements, field regions, reflections, and uncertainty. It should combine simultaneous sources as required and should not assume that a nominal separation distance alone demonstrates compliance.
Compliance may be demonstrated against the applicable reference levels or basic restrictions, using a method appropriate to the exposure configuration. The record should identify the assessed source states, publicly accessible locations, results, uncertainty, controls, and conditions on which the conclusion depends.
10.15.3 Designing For Public Safety
The most reliable public protection is achieved by designing the installation so that publicly accessible locations remain below the general public limits without requiring members of the public to recognize or manage an RF hazard.
Typical design measures include:
- locating antennas above or away from normal public access;
- providing sufficient antenna height and separation;
- directing main beams and predictable sidelobes away from accessible locations;
- selecting antenna patterns and mounting arrangements that limit accessible fields;
- limiting transmitter power or operating states where operationally acceptable;
- installing suitable shielding or screening; and
- designing buildings, platforms, and access routes around the assessed boundaries.
These measures should be verified during commissioning and reflected in drawings, source configuration records, exposure assessments, and change controls. A design assumption is not a continuing control unless the installation is maintained within that assumption.