Sec.  73.208   Reference points and distance computations.

   (a)(1) The following reference points must be used to determine distance
   separation requirements when petitions to amend the Table of Allotments
   ( Sec. 73.202(b)) are considered:

   (i) First, transmitter sites if authorized, or if proposed in applications
   with cut-off protection pursuant to paragraph (a)(3) of this section;

   (ii) Second, reference coordinates designated by the FCC;

   (iii) Third, coordinates listed in the United States Department of Interior
   publication entitled Index to the National Atlas of the United States of
   America; or

   (iv) Last, coordinates of the main post office.

   (The community's reference points for which the petition is submitted will
   normally be the coordinates listed in the above publication.)

   (2) When the distance between communities is calculated using community
   reference points and it does not meet the minimum separation requirements of
    Sec. 73.207, the channel may still be allotted if a transmitter site is
   available that would meet the minimum separation requirements and still
   permit the proposed station to meet the minimum field strength requirements
   of  Sec. 73.315. A showing indicating the availability of a suitable site should
   be sumitted with the petition. In cases where a station is not authorized in
   a community or communities and the proposed channel cannot meet the
   separation requirement a showing should also be made indicating adequate
   distance between suitable transmitter sites for all communities.

   (3) Petitions to amend the Table of Allotments that do not meet minimum
   distance separation requirements to transmitter sites specified in pending
   applications will not be considered unless they are filed no later than:

   (i) The last day of a filing window if the application is for a new FM
   facility or a major change in the non-reserved band and is filed during a
   filing window established under section 73.3564(d)(3); or

   (ii) The cut-off date established in a Commission Public Notice under
    Sec. 73.3564(d) and 73.3573(e) if the application is for a new FM facility or a
   major change in the reserved band; or

   (iii) The date of receipt of all other types of FM applications. If an
   application is amended so as to create a conflict with a petition for rule
   making filed prior to the date the amendment is filed, the amended
   application will be treated as if filed on the date of the amendment for
   purposes of this paragraph (a)(3).

   Note: If the filing of a conflicting FM application renders an otherwise
   timely filed counterproposal unacceptable, the counterproposal may be
   considered in the rulemaking proceeding if it is amended to protect the site
   of the previously filed FM application within 15 days after being placed on
   the Public Notice routinely issued by the staff concerning the filing of
   counterproposals. No proposals involving communities not already included in
   the proceeding can be introduced during the reply comment period as a method
   of resolving conflicts. The counterproponent is required to make a showing
   that, at the time it filed the counterproposal, it did not know, and could
   not have known by exercising due diligence, of the pendency of the
   conflicting FM application.

   (b) Station separations in licensing proceedings shall be determined by the
   distance between the coordinates of the proposed transmitter site in one
   community and

   (1) The coordinates of an authorized transmitter site for the pertinent
   channel in the other community; or, where such transmitter site is not
   available for use as a reference point,

   (2) Reference coordinates designated by the FCC; or, if none are designated,

   (3) The coordinates of the other community as listed in the publication
   listed in paragraph (a) of this section; or, if not contained therein,

   (4) The coordinates of the main post office of such other community.

   (5) In addition, where there are pending applications in other communities
   which, if granted, would have to be considered in determining station
   separations, the coordinates of the transmitter sites proposed in such
   applications must be used to determine whether the requirements with respect
   to minimum separations between the proposed stations in the respective
   cities have been met.

   (c) The method given in this paragraph shall be used to compute the distance
   between two reference points, except that, for computation of distance
   involving stations in Canada and Mexico, the method for distance computation
   specified in the applicable international agreement shall be used instead.
   The method set forth in this paragraph is valid only for distances not
   exceeding 475 km (295 miles).

   (1) Convert the latitudes and longitudes of each reference point from
   degree-minute-second format to degree-decimal format by dividing minutes by
   60 and seconds by 3600, then adding the results to degrees.

   (2) Calculate the middle latitude between the two reference points by
   averaging the two latitudes as follows:

   ML=(LAT1[dd]+LAT2[dd])÷2

   (3) Calculate the number of kilometers per degree latitude difference for
   the middle latitude calculated in paragraph (c)(2) as follows:

   KPD[lat]=111.13209−0.56605 cos(2ML)+0.00120 cos(4ML)

   (4) Calculate the number of kilometers per degree longitude difference for
   the middle latitude calculated in paragraph (c)(2) as follows:

   KPD[lon]=111.41513 cos(ML)−0.09455 cos(3ML)+0.00012 cos(5ML)

   (5) Calculate the North-South distance in kilometers as follows:

   NS=KPD[lat](LAT1[dd]−LAT2[dd])

   (6) Calculate the East-West distance in kilometers as follows:

   EW=KPD[lon](LON1[dd]−LON2[dd])

   (7) Calculate the distance between the two reference points by taking the
   square root of the sum of the squares of the East-West and North-South
   distances as follows:

   DIST=(NS2+ EW^2)^0.5

   (8) Round the distance to the nearest kilometer.

   (9) Terms used in this section are defined as follows:

   (i) LAT1[dd] and LON1[dd]=the coordinates of the first reference point in
   degree-decimal format.

   (ii) LAT2[dd] and LON2[dd]=the coordinates of the second reference point in
   degree-decimal format.

   (iii) ML=the middle latitude in degree-decimal format.

   (iv) KPD[lat]=the number of kilometers per degree of latitude at a given
   middle latitude.

   (v) KPD[lon]=the number of kilometers per degree of longitude at a given
   middle latitude.

   (vi) NS=the North-South distance in kilometers.

   (vii) EW=the East-West distance in kilometers.

   (viii) DIST=the distance between the two reference points, in kilometers.

   [ 28 FR 13623 , Dec. 14, 1963, as amended at  29 FR 14116 , Oct. 14, 1964;  48 FR 29505 , June 27, 1983;  52 FR 37788 , Oct. 9, 1987;  52 FR 39920 , Oct. 26, 1987;
    54 FR 9806 , Mar. 8, 1989;  57 FR 36020 , Aug. 12, 1992;  58 FR 38537 , July 19,
   1993]