Satellite DCS Use Concept Validation Project

The 401-402 MHz band is under increasing pressure from smallsat constellation companies to use for their satellite systems. The challenge is that, while meteorological aids uplink data to DCS Receivers and satellite operations downlink in the same band, the satellite downlinks are small omni-directional antennas that also send energy towards these GOES DCS Receivers. The result, as more and more of these satellite operations take place, is an aggregate effect of interfering with the DCS receiver and denying critical data from being received. While NOAA continues to work and negotiate with the smallsat companies and also with the spectrum regulatory authorities, effective, long-term solutions continue to remain elusive. Identifying an opportunity for satellite use of the DCS system is expected to alleviate some of these risks and further strengthen the value of maintaining this system capability.

The concept of the Satellite DCS Use Concept Validation project is to validate that LEO satellites are able to interface with the GOES hosted, and possibly other satellite, DCS Receivers and thereby enable a low rate data (300 to 1600 bps) service to satellite users; primarily to assist in launch, early orbit, and anomaly (LEO&A) operations. Satellite DCS users are good candidates for using available international DCS channels. There’s sufficient room in these DCS channels to allow a large number of satellite users to access the DCS through use of the international DCS band (IDCS). The IDCS is specifically configured to enable use between DCS receivers (GOES, METEOSAT, HIMAWARI) and so is well suited for using with LEO satellites. Current DCS users won’t be affected by this expanded use. It is expected that using DCS will assist in decreasing some of the risk of interference in the 400 MHz band, although it will not eliminate it. Additional regulatory controls and protections will continue to be needed as well.

While risk reduction to RFI in the 400 MHz band is the primary benefit, additional benefits have also been identified, such as:

• Increased use of the International channels, which are currently underutilized.
• Low cost enablement of scientific, educational, and development satellite low data rate communications to respective mission centers.
• Ability to enable LEO&A communications during clustered deployments.
• Projected demand for enabling the two-way communications capabilities of the DCS via GOES.
• Continued efforts by NOAA/NESDIS to facilitate good spectrum stewardship and efforts towards responsible sharing of spectrum resources.

The project development team has developed a fundamental plan to validate the satellite DCS use concept over the year. Since no change is required for the DCS receiver system, once this use is validated, it can also be used by the other DCS systems in the international community, thus expanding the availability of DCS satellite use in the international bands while further decreasing the pressure on the DCS spectrum.