Sec. 90.177  Protection of certain radio receiving locations.

    This section pertains to applications for new or modified 
authorizations in the vicinity of the National Radio Astronomy 
Observatory, Green Bank, Pocahontas County, WV, the Naval Radio Research 
Observatory, Sugar Grove, Pendleton County, WV, the Table Mountain Radio 
receiving zone, Boulder, CO, the Federal Communications Commission 
monitoring stations and other protected sites.
    (a) Any applicant for a new permanent base or fixed station, or for 
a modification of an existing authorization which would change the 
frequency, power, antenna height, directivity, or location within the 
boundaries described in paragraph (b) of this section shall notify the 
Director, National Radio Astronomy Observatory, P.O. Box 2, Green Bank, 
WV 24944, in writing, of the technical parameters of the proposal.
    (1) The notification shall be made prior to, or simultaneously with 
the filing of the application with the Commission.
    (2) The notification shall state the geographical coordinates of the 
antenna, antenna height, antenna directivity, proposed frequency, type 
of emission, and effective radiated power.
    (3) After receipt of such applications, the Commission will allow a 
period of 20 days for comments or objections in response to the 
notifications indicated. If an objection to the proposed operation is 
received during the 20-day period from the National Radio Astronomy 
Observatory for itself or on behalf of the Naval Radio Research 
Observatory, the Commission will consider all aspects of the problem and 
take whatever action is deemed appropriate.

[[Page 450]]

    (4) The provisions of this paragraph do not apply to applications 
for mobile, temporary base, or temporary fixed stations.
    (b) The area of concern for the National Radio Astronomy Observatory 
or the Naval Radio Research Observatory is the area bounded by 
39 deg.15' N. on the north, 78 deg.30' W. on the east, 37 deg.30' N. on 
the south, and 80 deg.30' W. on the west.
    (c) Protection for Table Mountain Radio Receiving Zone, Boulder 
County, Colorado. Applicants for a station authorization to operate in 
the vicinity of Boulder County, Colorado under this part are advised to 
give due consideration, prior to filing applications, to the need to 
protect the Table Mountain Radio Receiving Zone from harmful 
interference. These are the research laboratories of the Department of 
Commerce, Boulder County, CO. To prevent degradation of the present 
ambient radio signal level at the site, the Department of Commerce seeks 
to ensure that the field strengths of any radiated signals (excluding 
reflected signals) received on this 1800 acre site (in the vicinity of 
coordinates 40 deg.07'50'' N Latitude, 105 deg. 14'40'' W Longitude) 
resulting from new assignments (other than mobile stations) or from the 
modification or relocation of existing facilities do not exceed the 
following values:

------------------------------------------------------------------------
                                                   Field      Power flux
                                                  strength   density \1\
                                                 (millivolt    (dBW per 
                                                 per meter)     square  
                Frequency range                      in       meter) in 
                                                 authorized   authorized
                                                 bandwidth    bandwidth 
                                                 of service   of service
------------------------------------------------------------------------
Below 540 kHz.................................           10         65.8
540 to 1600 kHz...............................           20         59.8
1.6 to 470 MHz................................           10         65.8
470 to 890 MHz................................           30         56.2
Above 890 MHz.................................            1         85.8
------------------------------------------------------------------------
\1\ Equivalent values of power flux density are calculated assuming free
  space characteristic impedance of 376.7=120 ohms.            

    (1) Advance consultation is recommended particularly for those 
applicants who have no reliable data which indicates whether the field 
strength or power flux density figures in the above table would be 
exceeded by their proposed radio facilities (except mobile stations). In 
such instances, the following is a suggested guide for determining 
whether coordination is recommended:
    (i) All stations within 2.4 km (1.5 statute miles);
    (ii) Stations within 4.8 km (3 statute miles) with 50 watts or more 
effective radiated power (ERP) in the primary plane of polarization in 
the azimuthal direction of the Table Mountain Radio Receiving Zone;
    (iii) Stations within 16 km (10 statute miles) with 1 kW or more ERP 
in the primary plane of polarization in the azimuthal direction of the 
Table Mountain Receiving Zone;
    (iv) Stations within 80 km (50 statute miles) with 25 kW or more ERP 
in the primary plane of polarization in the azimuthal direction of the 
Table Mountain Receiving Zone.
    (2) Applicants concerned are urged to communicate with the Radio 
Frequency Management Coordinator, Department of Commerce, Research 
Support Services, NOAA R/E5X2, Boulder Laboratories, Boulder, CO 80303; 
telephone (303) 497-6548, in advance of filing their applications with 
the Commission.
    (3) The Commission will not screen applications to determine whether 
advance consultation has taken place. However, applicants are advised 
that such consultation can avoid objections from the Department of 
Commerce or proceedings to modify any authorization which may be granted 
which, in fact, delivers a signal at the site in excess of the field 
strength specified herein.
    (d) Protection for Federal Communications Commission monitoring 
stations:
    (1) Applicants in the vicinity of an FCC monitoring station for a 
radio station authorization to operate new transmitting facilities or 
changed transmitting facilities which would increase the field strength 
produced over the monitoring station over that previously authorized are 
advised to give consideration, prior to filing applications, to the 
possible need to protect the FCC stations from harmful interference. 
Geographical coordinates of the facilities which require protection are 
listed in Sec. 0.121(c) of the Commission's Rules. Applications for 
stations (except mobile stations) which will

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produce on any frequency a direct wave fundamental field strength of 
greater than 10 mV/m in the authorized bandwidth of service (-65.8 dBW/
m2 power flux density assuming a free space characteristic 
impedance of 120 times pi, or 377, ohms) at the referenced coordinates, 
may be examined to determine extent of possible interference. Depending 
on the theoretical field strength value and existing root-sum-square or 
other ambient radio field signal levels at the indicated coordinates, a 
clause protecting the monitoring station may be added to the station 
authorization.
    (2) In the event that calculated value of expected field exceeds 10 
mV/m (-65.8 dBW/m2) at the reference coordinates, or if there 
is any question whether field strength levels might exceed the threshold 
value, advance consultation with the FCC to discuss any protection 
necessary should be considered. Prospective applicants may communicate 
with: Chief, Compliance and Information Bureau, Federal Communications 
Commission, Washington, DC 20554, Telephone (202) 632-6980.
    (3) Advance consultation is suggested particularly for those 
applicants who have no reliable data which indicates whether the field 
strength or power flux density figure indicated would be exceeded by 
their proposed radio facilities (except mobile stations). In such 
instances, the following is a suggested guide for determining whether an 
applicant should coordinate:
    (i) All stations within 2.4 kilometers (1.5 statute miles);
    (ii) Stations within 4.8 kilometers (3 statute miles) with 50 watts 
or more average effective radiated power (ERP) in the primary plane of 
polarization in the azimuthal direction of the Monitoring Stations;
    (iii) Stations within 16 kilometers (10 statute miles) with 1 kW or 
more average ERP in the primary plane of polarization in the azimuthal 
direction of the Monitoring Station;
    (iv) Stations within 80 kilometers (50 statute miles) with 25 kW or 
more average ERP in the primary plane of polarization in the azimuthal 
direction of the Monitoring Station.
    (4) Advance coordination for stations operating above 1000 MHz is 
recommended only where the proposed station is in the vicinity of a 
monitoring station designated as a satellite monitoring facility in 
Sec. 0.121(c) of the Commission's Rules and also meets the criteria 
outlined in paragraphs (d)(2) and (3) of this section.
    (5) The Commission will not screen applications to determine whether 
advance consultation has taken place. However, applicants are advised 
that such consultation can avoid objections from the Federal 
Communications Commission or modification of any authorization which 
will cause harmful interference.
    (e) In the band 420 to 450 MHz, applicants should not expect to be 
accommodated if their area of service is within 160 kilometers (100 
miles) of the following locations:

(1) 45 deg.45'' N., 70 deg.32' W,
(2) 64 deg.17' N., 149 deg.10' W,
(3) 48 deg.43' N., 97 deg.54' W;


within 200 kilometers (124 miles) of the following locations:

(1) 32 deg.38' N., 83 deg.35' W,
(2) 31 deg.25' N., 100 deg.24' W;


within 240 kilometers (150 miles) of the following location:

(1) 39 deg.08' N., 121 deg.26' W;


within 320 kilometers (200 miles) of the following locations:

(1) 28 deg.21' N., 80 deg.43' W,
(2) 30 deg.30' N., 86 deg.30' W,
(3) 43 deg.09' N., 119 deg.11' W;


or in the following locations:

(1) The state of Arizona,
(2) The state of Florida,
(3) Portions of California and Nevada south of 37 deg.10' N,
(4) And portions of Texas and New Mexico bounded by 31 deg.45' N., 
34 deg.30' N., 104 deg.00' W. and 107 deg.30' W.

(Secs. 4, 303, 307, 48 Stat., as amended, 1066, 1082, 1083; 47 U.S.C. 
154, 303, )
[43 307 FR 54791 , Nov. 22, 1978, as amended at  44 FR 77167 , Dec. 31, 1979; 
 47 FR 34420 , Aug. 9, 1982;  49 FR 32770 , Aug. 16, 1984;  50 FR 39003 , 
Sept. 25, 1985;  54 FR 38680 , Sept. 20, 1989;  54 FR 39740 , Sept. 28, 
1989;  61 FR 8478 , Mar. 5, 1996]