§  25.259   Time sharing between NOAA meteorological satellite systems and
non-voice, non-geostationary satellite systems in the 137–138 MHz band.

   (a) A non-voice, non-geostationary mobile-satellite service system
   licensee (“NVNG licensee”) time-sharing spectrum in the 137–138 MHz
   frequency band shall not transmit signals into the “protection areas”
   of National Oceanic and Atmospheric Administration (“NOAA”) satellite
   systems. When calculating the protection areas for a NOAA satellite in
   the 137.333–137.367 MHz, 137.485–137.515 MHz, 137.605–137.635 MHz and
   137.753–137.787 MHz bands, a NVNG licensee shall use an earth station
   elevation angle of five degrees towards the NOAA satellite and will
   cease its transmissions prior to the NVNG licensee's service area,
   based on an elevation angle of zero degrees towards the NVNG licensee's
   satellite, overlapping the NOAA protection area. When calculating the
   protection areas for a NOAA satellite in the 137.025–137.175 MHz and
   137.825–138 MHz bands, a NVNG licensee shall use an earth station
   elevation angle of zero degrees, or less if reasonably necessary,
   towards the NOAA satellite and will cease its transmissions prior to
   the NVNG licensee's service area, based on an elevation angle of zero
   degrees towards the NVNG licensee's satellite, overlapping the NOAA
   protection area. A NVNG licensee is responsible for obtaining the
   necessary ephemeris data. This information shall be updated system-wide
   on at least a weekly basis. A NVNG licensee shall use an orbital
   propagator algorithm with an accuracy equal to or greater than the
   NORAD propagator used by NOAA.

   (b) A NVNG licensee time sharing spectrum in the 137–138 MHz band shall
   establish a 24-hour per day contact person and telephone number so that
   claims of harmful interference into NOAA earth station users and other
   operational issues can be reported and resolved expeditiously. This
   contact information shall be made available to NOAA or its designee. If
   the National Telecommunications and Information Administration (“NTIA”)
   notifies the Commission that NOAA is receiving unacceptable
   interference from a NVNG licensee, the Commission will require such
   NVNG licensee to terminate its interfering operations immediately
   unless it demonstrates to the Commission's reasonable satisfaction, and
   that of NTIA, that it is not responsible for causing harmful
   interference into the worldwide NOAA system. A NVNG licensee assumes
   the risk of any liability or damage that it and its directors,
   officers, employees, affiliates, agents and subcontractors may incur or
   suffer in connection with an interruption of its non-voice,
   non-geostationary mobile-satellite service, in whole or in part,
   arising from or relating to its compliance or noncompliance with the
   requirements of this paragraph (b). The Commission will not hesitate to
   impose sanctions on a NVNG licensee time-sharing spectrum in the
   137–138 MHz band with NOAA, including monetary forfeitures and license
   revocations, when appropriate.

   (c) Each satellite in a NVNG licensee's system time-sharing spectrum
   with NOAA in the 137–138 MHz band shall automatically turn off and
   cease satellite transmissions if, after 72 consecutive hours, no reset
   signal is received from the NVNG licensee's gateway earth station and
   verified by the satellite. All satellites in such NVNG licensee's
   system shall be capable of instantaneous shutdown on any sub-band upon
   command from such NVNG licensee's gateway earth station.

   [ 62 FR 59296 , Nov. 3, 1997]