Space Weather Usage of Radio Frequencies and Managing its Risk from Interference

The international usage of the radio spectrum has been managed and coordinated internationally by the International Telecommunications Union (ITU) for over 100 years. The mechanism for this coordination lies in the treaty-level international Radio Regulations, which are revised at roughly four-year intervals. Many of these revisions are in response to advances in technology which allow new services to be introduced and higher frequencies to be utilized.

The Space Weather community has been using various bands of the radio spectrum for uses varying from the relatively narrow-band monitoring of solar radio emissions to wide-band applications such as sounding the ionosphere. While some of the frequency bands used are protected from interference by the Radio Regulations (e.g., the sun is monitored in some bands under the protection of the internationally recognized Radio Astronomy Service), many frequency bands are being used under a "cause no interference, absorb any interference" basis – that is, with no regulatory protection whatsoever. Such usage is legal both internationally and locally within the United States. However, the implication is that the un-recognized Space Weather applications are at risk for interference from future authorized operations of recognized services.

As an example, today the radio local area network (RLAN or “WiFi”) and cellular and mobile broadband service providers are eagerly seeking more spectrum, which will come with protection for them but not for the Space Weather applications also using overlapping radio spectrum.  To guard against such unwanted interference to radio observations crucial to Space Weather, Space Weather should seek official recognition if it’s operations which do not fall within a service already identified (as noted before, some operations of Space Weather appear to overlap with that of the already recognized Radio Astronomy Service).

Noting the transition of Space Weather from a scientific research mode to an operational mode, the ITU, at its last World Radiocommunications Conference (WRC-2015), posed the question of whether Space Weather should be formally recognized and if so, what regulatory protections should be afforded its operations.

The NOAA and NASA spectrum management team is prepared to do the necessary interference and sharing studies for the ITU and the Space Weather community, but the team requires input in the form of the operational and technical characteristics of the radio spectrum-reliant Space Weather sensor systems in use or planned for in the future. Without this critical information, the team’s efforts within the ITU will be futile. Such required information includes:

1. a brief description of the operational usage of the band,
2. a description of the sensor system and output products,
3. the center frequencies and bandwidths used,
4. filter characteristics,
5. the system noise temperature,
6. the noise equivalent delta-T,
7. the measurement integration time(s),
8. antenna parameters, and
9. deployment characteristics (satellite based,  or terrestrial based with locations of installations, etc.).

The NOAA and NASA spectrum management team is seeking the above information from the Space Weather operators so that it can conduct the relevant studies and, if necessary, seek to obtain appropriate regulatory protections for Space Weather operations.

This contribution outlines the development process and schedules that are in place to provide the regulatory and operational answers that would be considered at the WRC occurring in 2019.  Current status of studies and a review of the on-going compilation of Space Weather instrument parameters will be provided.