May 25, 2021

AGU sends letter on Spectrum issues to Senate leadership

Posted by Caitlin Bergstrom

On 20 May 2021, AGU, The American Meteorological Society and the National Weather Association sent a letter to Senator Maria Cantwell (WA), Chair of the Committee on Commerce, Science, and Transportation calling for leadership on Spectrum issues, including the importance of spectrum assets to national security and weather and hazards safety.  


Thank you for your voice of leadership to preserve diverse spectrum resources to sustain and advance crucial environmental information and forecasting. We appreciated your remarks during now Secretary of Commerce Gina Raimondo’s nominating hearing in January supporting the need to safeguard critical spectrum assets to enable continued weather forecasting, water management and environmental modeling, and your comments during the executive session of the committee on May 12, 2021 on weather and federal spectrum coordination. The co-signers of this letter, who are some of the leading Earth science and weather organizations in the U.S. and world, are grateful for your leadership in this area.


The past few years have been challenging as the weather and water communities have worked to defend our spectrum assets that are crucial to the operation of critical environmental sensors and GPS dependent technologies operated by the private sector, academia and federal agencies like NOAA, NASA and the Department of Defense.


We welcome your leadership as Chair of the U.S. Senate Committee on Commerce, Science and Transportation to advance environmental forecasting and hazard prediction, which can only happen if existing spectrum assets in the L-Band and key passive bands are protected from interference. We are looking to you for continued support in the following areas:

    • Safeguard real-time environmental information for severe weather, aviation, wildfire prediction and marine transportation provided by NOAA’s geostationary weather satellites (GOES) as well as the GPS and satellite communication assets relied upon by numerous industries to keep people safe and informed of hazards. It is critical for the FCC to reverse its April 2020 L-Band GPS decision and prevent any further consideration of Ligado’s other proposal directly impacting GOES and its reliance on 1675-1680 MHz.
    • Protect information from passive microwave sensors that provide crucial inputs to weather models.

The spectrum adjoining 24 GHz, 50 GHz and 90 GHz, provides important information ranging from hurricane forecasting to precipitation estimates to improve forecasts. These measurements are unique to these spectral areas and cannot be obtained elsewhere.

    •  Prior to any further auctions, there must be further research and balanced dialogue to find reasonable solutions that value the full economic significance and impact of weather forecasting and water resources management.
    • In addition, there is a need for funding and technology development to detect contamination in the passive bands and the full impact of growing terrestrial operations on these crucial microwave observations as a result of the FCC’s spectrum allocation actions.

A nationwide survey indicated that weather forecasts generated $35 billion in economic benefits to U.S. households in 2016.2 Since this only addresses households and weather, the value of this spectrum- reliant environmental information is likely far more vast. The spectrum for these systems also support weather forecasts and warnings more broadly that contribute to a range of economic activity from local governments making evacuation decisions to grocery stores planning their supply schedules and routes.


Weather apps are some of the most used in the world, so we directly recognize the value of expanding 5G technologies across the U.S.3 But we believe that such growth must be balanced to ensure other critical national assets such as environmental satellites and other weather and water technologies be safeguarded since their failure will cost the nation in both lives and local economies. For spectrum sharing to work, greater investment in innovation is required across disciplines, including engineering and economics, to enable these technologies to safely coexist. Right now, spectrum sharing initiatives have not yet proven sufficient to support weather forecasting, which is highly time sensitive and cannot tolerate interference.4 The wireless industry has not been open to dialogue about possible technologies and techniques they could employ to address weather enterprise concerns, especially related to passive microwave observations for modeling.


We have requests in two areas:

1)  We ask that you continue to ask questions of future nominees to the FCC and the Department of Commerce, especially NTIA, encouraging them to fully account for the threat to life, property, and the economy of interference to weather information when making decisions about spectrum allocation.

2)  We request that you work in partnership with the leadership of the Senate Armed Services Committee to encourage the FCC to reverse its decision on Ligado related to GPS and satellite communications, and to deny the Ligado proposal to share spectrum with NOAA’s GOES satellites.


Once again, thank you for your voice on these important issues and we look forward to working with you on these critical issues to weather forecasting moving forward.


Read the full letter here.