FRS/GMRS Radio Mapping Guide
Radio mapping[1] is the process of creating a visual representation of radio signal strengths and coverage areas across specific geographic locations; in this case, a team's Service Area. A radio map highlights areas with strong, weak, or no signal, helping organizations understand coverage patterns, identify dead zones, and optimize communication infrastructure.
Introduction to Radio Mapping
Scenario
A disaster has struck the Portland metropolitan area. Routine communications methods (e.g. cell phones) are disabled, and NETs are self-deploying to their Staging Areas/Incident Command Posts. After making some initial assessments, Incident Team Leaders begin deploying strike teams to render aid in the surrounding neighborhoods.
After dispatching a strike team to travel a specific route, the Incident Team Leader discovers they cannot establish FRS/GMRS radio communications with them. Time passes and nothing is heard. Is the team in a radio dead zone? Have their radios failed? Is the team in trouble? Should the Incident Team Leader dispatch a runner to their last known location? Does the strike team need the assistance of a follow-up strike team? Where are they?
Meanwhile, the strike team discovers they can no longer communicate with the NET Incident Command Post. How can they reestablish communications? Should they double back to the last point of communication, risking wasted time and physical exertion? Should they continue forward and hope to reestablish communications at a future location? How long will that take? If the team is in serious trouble, should they detour from their route to call for help? If so, in which direction?
The purpose of FRS/GMRS radio mapping is to provide some solutions for addressing these types of questions in an already stressful situation.
Method
FRS/GMRS mapping may be conducted by placing a two-person team, one Radio Operator and one Scribe, at a proposed NET Incident Command Post location. Rover Teams report to the Radio Operator as they stop at specific locations throughout the NET Service Area. The Radio Operator and the Rover Teams record the radio voice quality for the conversation, as they heard it, at each location. The radio voice quality values for each reported location are then used to create color-coded maps for Incident Command staff and Strike Teams for use during large-scale disaster response.
Goals
The primary goal of a Radio Coverage Survey is to measure the radio voice quality of FRS/GMRS radio communications within a prescribed NET Service Area.
The radio voice quality values may be used to:
- Validate prospective primary and backup locations for a NET Incident Command Post;
- Determine radio voice quality at points throughout the NET Service Area;
- Scope out potential locations for an FRS/GMRS repeater or relay sites.
The process of radio mapping with team members will also:
- Improve radio skills;
- Increase familiarity of the NET Service Area;
- Allow practice of elements of the Incident Command System (ICS);
- Build team cohesiveness; and,
- Cultivate an understanding of radio communication coverage patterns to reduce uncertainty and anxiety during a major disaster.
Radio Coverage Survey Sessions
A team working together can accomplish a Radio Coverage Survey Session in a series of one-and-a-half to two-hour periods. These short sessions enable more volunteers to participate and may be scheduled any time or day of the week.
Survey documents
Several documents available here for download and printing can facilitate a Radio Survey. They include:
| Document | Download | Last Update |
|---|---|---|
| Radio Coverage Survey Action Plan | [PDF] | 2024.11.10 |
| Radio Survey - Command/Listening Post Log | [PDF] | 2024.09.20 |
| Radio Survey - Rover Team Log | [PDF] | 2024.09.19 |
| Survey Area Maps | [PDF] | |
| NET Form 2A Personnel Check In | [PDF] | |
| NET Form 3 Team Leader Assignment Tracking Log | [PDF] |
Radio Coverage Survey Action Plan
The key elements of a Survey Action Plan should include, at the minimum:
- “What we are going to do”: the goals and plan for the survey;
- “Who is responsible for doing it”: participant assignments;
- “How do we communicate with each other”: survey radio protocols; and
- “What is the procedure if someone is injured”: work in pairs, apply first aid, and contact Command Post and/or 911 as need be.
Additional elements of the Survey Action Plan should include instructions for using Survey Log forms and Survey Area Map.
The Radio Coverage Survey Action Plan, including radio protocols, should be reviewed with survey participants in a NET meeting before the first radio mapping session. Additionally, survey participants should review the action plan before each session. A sample Radio Coverage Survey Action Plan is available as a fillable form in the table above or download here, and can be modified for the NET Service Area surveyed.
Notes and References
- ↑ Also referred to as Service Area FRS/GMRS Radio Voice Quality Survey, but we truncate to "radio mapping" to keep it simple and save money on digital ink.