§  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 (§ 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 § 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 § 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
   § 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 = (LAT1dd + LAT2dd) ÷ 2

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

   KPDlat = 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:

   KPDlon = 111.41513 cos(ML)-0.09455 cos(3ML) + 0.00012 cos(5ML)

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

   NS = KPDlat(LAT1dd-LAT2dd)

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

   EW = KPDlon(LON1dd-LON2dd)

   (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 + EW2)0.5

   (8) Round the distance to the nearest kilometer.

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

   (i) LAT1dd and LON1dd = the coordinates of the first reference point in
   degree-decimal format.

   (ii) LAT2dd and LON2dd = the coordinates of the second reference point
   in degree-decimal format.

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

   (iv) KPDlat = the number of kilometers per degree of latitude at a
   given middle latitude.

   (v) KPDlon = 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]