Policy
Visitors to the Green Bank Observatory and surrounding area should help protect our observations by leaving all electronic devices at home. If you cannot do that, please disable all wireless signals on your mobile phones and other electronic devices. (How do I disable devices?) Medical devices, like pacemakers, hearing aids, and insulin pumps, do not have to be turned off.
Wondering what types of equipment cause interference with our science? Equipment that causes interference comes in two varieties
- intentional, and
- unintentional transmitters
Intentional transmitters deliberately give off radio signals, usually for communication purposes. These are devices such as cell phones, Bluetooth headphones, WiFi, cordless telephones, car radar (alert) systems, and so forth. All of these devices are prohibited to be used on site, unless all transmissions from the device are turned completely off.
Unintentional transmitters are devices that give off radio waves as a side product, usually as radio ‘noise’ coming from the device. Unintentional transmitters include most digital equipment – gasoline vehicles, electric bikes and scooters, cell phones with the intentional transmissions turned off, digital cameras, computers, etc. Unintentional transmissions can also occur when there is a fault, or short, in the electrical lines of a system, such as a short in an electric fence or power line. Unintentional transmitters are prohibited in the telescope zone one site (Zone 1).
Please note that all site visitors and staff must follow site RFI and safety regulations.
Site Zones
The Green Bank Observatory is a unique resource for Radio Astronomy. We are located in the National Radio Quiet Zone (NRQZ) which provides protection from permanent, fixed, licensed transmitter services. Our location, surrounded by National Forest and the mountainous terrain of West Virginia, also serves to protect observations. Additionally, the West Virginia Radio Astronomy Zoning Act allows us to prohibit the use of any electrical equipment within a ten mile radius that causes interference to Radio Astronomical Observations.
On the Green Bank Site our protection policy differentiates two zones, one for the laboratory, housing, and visitor facilities (Zone 2), and one for the Radio Astronomical Instruments themselves (Zone 1) as illustrated on the following map:
In Zone 1 a preventative, proactive approach is used. Interference potential is assessed through testing, and equipment is shielded, filtered, etc. as necessary before installation or use. By policy, we do not install equipment first and then mitigate it if it happens to cause interference. We additionally protect this zone by limiting motorized traffic to approved diesel vehicles, and all persons in Zone 1 should leave their electronic devices behind, whether they are entering by foot, bus, vehicle, bike, or any other means.
So, for Zone 1:
- All digital cameras, cell phones, fitness trackers or similar devices should be left at home or have transmissions turned off and be left in your office, or in your vehicle the Jansky Lab, or in your car or residence. (How do I turn off my device?).
- If your work involves any equipment that will be left behind after you leave, whether it is installed or just overnight our out of work hours, that equipment must be tested and approved or given a waiver before being brought into Zone 1.
- Temporary equipment which is known, or likely, to cause interference must be given a waiver in advance of entering Zone 1.
- Only approved diesel vehicles are allowed in Zone 1.
Remember – the GBT is not the only instrument on site. We have many project sharing out facility. As a result, coordinating with the GBT schedule is not sufficient.
Zone 2 includes the laboratory, housing, and visitor facilities. Here we differentiate between intentional and unintentional radiators. An intentional radiator is any device that intentionally, or is known, to transmit radio waves. All intentional, and known, radiators are prohibited unless a waiver for their use has been granted. Prohibited devices include cordless telephones, Bluetooth headsets and other devices, most raspberry pi and similar small computing boards, cell phone which do not have all transmissions completely off, microwave ovens, etc. A good rule of thumb is, if it uses radio frequency energy to communicate, it is likely prohibited. Waivered devices include site radios when used exclusively for the safety of staff and visitors (43 MHz radios), 2.4 GHz WiFi (in Zone 2b only), and Bluetooth devices which are necessary for the safety of staff (e.g. heart and blood sugar monitors).
Following these simple guidelines goes a long way toward preserving the relatively RFI quiet environment at Green Bank Observatory. Your cooperation is vital to protecting the research that we do.
If you have any questions, feel free to reach out to the Green Bank IPG (gbipg or gbipg-lead).
The complete Site IPG Policy (updated (09/2025) is available here.