Spectrum Considerations for GOES / GOES-R DCS David G. Lubar GOES-R Program Office/ PSE-Spectrum Management The Aerospace Corporation May 4, 2016 Prepared for the STIWG – Intended for Government and Support Contractors Only Not for Unlimited Release

Background Radio spectrum has become a popular commodity essential to the masses to power smartphones, tablets, and wireless devices. As demand increases for download of video and more bandwidth-intensive applications, the commercial broadband industry looks for more and more spectrum resources And the predominant source of electromagnetic spectrum is the Federal government, according to the calls for repurposing of Federal bandwidth by prospective purchasers. When and how this this effort take hold and what does it have to do with the Data Collection System users?

Presidential Memorandum’s On Spectrum Repurposing or Sharing Repurposing received significant momentum in 2010 and a stated goal for 500 MHz of spectrum available by 2020 from the President’s first memorandum: First Memorandum Highlights 500 MHz in 10 years by vacating or sharing Provides a timetable and process Selection of candidate Federal bands Calls for an annual update report Further specific action focused on spectrum sharing was directed in a second memorandum in 2013: Second Memorandum Highlights Spectrum Sharing versus Relocation Creation of a Spectrum Policy Team Quantative assessments

1675-1695 MHz Meteorological Use Current Use or Planned GOES- NOP AWS-3 Broadband GOES-RSTU L-band downlink spectrum is shown on the current (GOES NOP) and future generations (GOES-R S T & U) of the nation’s geostationary weather satellites. Major links are shown, with items in “blue” indicative of NOAA L-band broadcast downlinks in this band. Also shown are the handset to tower services just sold in the AWS-3 auction and the tower-to-handset services in spectrum leased by Ligado Networks in 1670-1675 MHz and the red outlined spectrum has been requested for sharing for future sale or auction to Ligado. Broadband AWS-3

Spectrum Sharing Proposal As many of you know, a commercial company has requested that 1675-1680 MHz spectrum be shared with their proposed terrestrial transmitters for smartphones and tablets. In the GOES-R era, DCPR downlinks into DRGS receivers operate in 1679.7-1680.4 MHz. The LTE signal would overlap DCPR, although the top end of the LTE signal includes a “guard band” for isolation with an adjacent LTE signal. Significant radio frequency interference is possible with a DCS receiving system within the US & P, if this occurs.

How Does This Proposed Sharing Impact DCS? A terrestrial company has petitioned the FCC to consider sharing 1675-1680 MHz with the current NOAA meteorological satellite downlink usage As NTIA and the various Federal groups select candidate spectrum bands to recommend for sharing with commercial users, it is possible that 1675-1680 MHz could be included as a candidate. We will know when the sixth annual update report as stated in the June 2010 Presidential Memorandum is issued by NTIA. That update may be released about the time the STIWG is being conducted, if past year’s report timing are any indication. Bottom Line: Having strong cellular towers in the same spectrum as DCPR will likely be a significant source of radio frequency interference to the weaker satellite downlink signals sent from GOES-R containing DCP information. The impact to agencies and their Federal and non-Federal end user beneficiaries of the DCP data must be appreciated and understood by all.

DCS Frequencies GOES-NOP and GOES-R Background DCS frequencies in the Americas could be subject to interference from proposed or planned systems DCS Frequencies GOES-NOP and GOES-R Function GOES (MHz) GOES-R (MHz) DCPR (uplink) 401.9-402.2 401.7-402.4 DCPR (downlink) 1694.5-1694.8 1679.7-1680.4 DCPI / DCPC (uplink) 2034.8875, 2034.9, 2034.9125 DCPC 2032.775, 2032.825 DCPI / DCPC (downlink) 468.8125, 468.825, 468.8375 DCPC 468.775, 468.825

Spectrum Proposed or Secondary Usage On-going request by Ligado Networks (formerly LightSquared) to share 1675-1680 MHz between NOAA and terrestrial tower transmitters. FCC Public Notice was issued April 22 Original FCC Proceeding number RM-11681 is on the Internet NTIA is due to issue an updated list of Federal band candidates for sharing in late April or early May. FCC has granted permission for Spire Global (a commercial remote sensing satellite constellation) to uplink in 402-403 MHz from domestic earth stations to nine satellites in non-GEO orbit, on a non-interference basis Initial computations place these signals about the same power level as a DCP into the GOES/GOES-R spacecraft UHF receiver Quick action by DOC Office of Radio Frequency Management and NESDIS frequency management drove FCC to force 24 hour/day “stop buzzer” contact at Spire to shut down if interference reported

FCC Public Notice 1675-1680 MHz FCC Notice issued Friday April 22 http://transition.fcc.gov/Daily_Releases/Daily_Business/2016/db0422/DA-16-443A1.pdf Solicitation for users of GOES & GOES-R in 1675-1680 MHz band FCC looking for input on non-federal users that benefit from the data in this spectrum Need input from current uses and regarding future GOES-R usage How do non-Federal entities make use of [Federal] products and services ? Petitioner suggests cloud delivery and alternative methods Additional requests to comment on studies by the petitioner Alion reports on NOAA Operations use of GOES and GOES-R Adequacy of AWS-3 Protection Zones Potential for anomalous propagation (thermal ducting) for DCPR sites Can you co exist with 32 dBW tower transmitters?

Public Notice Response Unfortunately, Federal agencies can not directly participate in FCC public comment proceedings However, an agency can submit a letter via NTIA, (with their concurrence) State, Local, Tribal and Private users should be encouraged to speak up and file letters in this RM-11681 proceeding Initial comments are due by June 21, 2016 Then commenters are allowed to review and comment on what has already been filed. These review comments are due by July 21, 2016 This spectrum band has a high likelihood to be listed on NTIA’s list of bands to be considered for commercial spectrum sharing – the sixth interim progress report on the President’s Ten Year (Spectrum) Plan is forthcoming from NTIA This is the hydrological community’s one (and perhaps only) chance to indicate how this information is used, what it contributes to the economy and to public safety.

User Input for FCC Public Notice It will be critical to get end users to provide comment to the forthcoming FCC Public Notice on use of 1675-1680 MHz. FCC desires information on non-Federal use (or on non-Federal users benefiting from Federal use of this spectrum)

1675-1680 MHz spectrum sharing History Noted letters in FCC proceeding LightSquared first asked for sharing in 2012, as a petition to the FCC in proceeding RM-11681 President’s budget has contained a legislative recommendation to FCC for past 3 or 4 years to auction or make 1675-1680 MHz available by fee action for terrestrial use. (Page 11 of FY17 request) LightSquared renamed Ligado Networks in February 2016 17 congressmen sent letter to FCC urging adaptation of 1675-1680 MHz as soon as possible for shared terrestrial use Noted letters in FCC proceeding AMS/NWA July 2015 AMS/NWA March 2016 National Hydrologic Warning Council March 2016 World Meteorological Organization Congressional Letters National Weather Association March 2016

Summary and Action on Spectrum Sharing In the past we may have sounded like “the sky is falling”, and little response from affected end beneficiaries of DCS resulted – although the DCS community loudly voiced it’s concern Now, “the sky is falling and it’s burning” This FCC proceeding is the one and only chance to voice concerns to regulators before they decide whether or not to share this spectrum with terrestrial transmitters. Source wnyc.org It is important that non-Federal users and beneficiaries comment in the RM-11681 FCC process

Small Satellite Constellations in the 401-403 MHz Band as an uplink The amount of small satellite constellations, either being proposed or being constructed is growing monthly. For US systems, the FCC often issues either experimental authorizations on a non-interference basis, or a Part 25 license. Two examples of constellations that have asked to uplink in or near the DCP uplink band: Spire Global’s LEMUR-2 Astro Digital (Aquila Space) Landmapper constellation/Corvus-BC-3 sat. System Frequency (MHz) LEMUR-2 29 satellites 402-403 MHz up 13 US Gnd stations Non-interference basis authorization Corvus-BC-3 402.58-402.62 MHz up Filing says they avoided DCS freq.

Small Satellite Constellations There are currently a large number of satellite constellations in stages of deployment in US. Most conform the the US Table of Frequency Allocations that dictates usage and direction of transmission between space and ground antennas. One commercial remote sensing system requested an exception so they can uplink in the 402-403 MHz band – Spire Global Spire Satellite

Overview Will the Lemur uplink at 406.525 MHz GOES-R Geostationary Will the Lemur uplink at 406.525 MHz overload the GOES-R UHF receiver front end amplifier, and what might be the impact of this overload condition? 406.525 MHz Lemur LEO 401.9 +/- 0.2 MHz Lemur uplink Data Collection Platforms

Conditional Grant by FCC for Spire’s Authorization Spire was granted authorization for 9 satellites to deploy at altitudes below 435 km either from ISS or from Cygnus cargo capsule. Spire operations 402-403 uplink, 2020-2025 MHz downlink are on a non-harmful interference basis They must provide a stop buzzer POC to NESDIS F.M. and to NTIA 24/7/365. The 9 satellites have a license term of 18 months LEMUR-2 Satellites CYGNUS OA-6 docked On March 26 at the ISS. 9 Lemur satellites are onboard Understand plan is to launch these satellites (& 20 Dove Flock 2e for Planet Labs) after CYGNUS OA-6 disconnects from the ISS on May 20 during it’s 8 day return to Earth and disposal over the South Pacific Spire Conditional Grant Dated March 26, 2016

Small Satellites & DCS Cases should be evaluated against the spacecraft receiver properties with DCP signal loading considered There is no definitive analysis showing that these systems may cause issues in the GOES or GOES-R DCS UHF receiver on orbit However, if multiple systems are visible at the same time, and if their signal strengths differ considerably, intermodulation products could occur within the spacecraft receiver Mathematically they may fall outside the domestic DCS band, the cases would require computation and due diligence.

Small Satellite Summary There are many new small satellites planned within the US and international regulatory processes They feature different degrees of rigor in their spectrum management efforts, and some do uplink in or near the DCPR frequencies in 401-402 MHz Recommend that recorded anomalous signal levels from DADDS be reported to NOAA NESDIS Frequency Management, along with date, time and exact channel frequenc(ies). This may be the only way to determine if ground uplinks servicing small satellite constellations are causing interference to DCS operations. To date no such cases have been reported to FM These systems, many of which support environmental measurements and remote sensing, useful to NOAA, must not detract from other satellite services due to radio frequency interference.

Summary Demands for spectrum are growing and new systems are being created on an unprecedented basis. Voicing your needs via an agency spectrum official is now a necessity, not a luxury, and receiving user and non-Federal partner inputs to the FCC is also paramount as they seek to make spectrum sharing or repurposing decisions in support of the broadband wireless community Silence in the spectrum community is assumed to be consent