[BC] GPS recommendations

[Tim Sawyer]

Such a pain in the ass isn't it? Only the FCC mass media bureau uses NAD 27
and only for antenna locations in the CONUS, outside the CONUS at one time
you were suppose to use the local datum i.e., Guam, Saipan, Puerto Rico and
Hawaii which was another mess in and of itself - those areas have all
adopted NAD83 as the standard datum now - so for those areas you use NAD83.
So in effect the mass media bureau database has a mixture of both NAD27 and
NAD83 coordinates - "they" just don't want to talk about it or give you the
option to specify the datum on the forms.
 
Data point collection (for example AM field measurements) are totally
acceptable using the NAD 83 datum just tell them (the fcc) the datum used.
I usually convert the site coordinates to WGS84/NAD83 and tell the field
engineers to run distance and bearing from there using the native
NAD83/WGS84 of the gps unit.

I ask field engineers not to do any datum conversions just tell me what
datum the data is in and I'll handle any conversions if necessary. 

The 1988 GPS document Alan brings up? 24 years ago! and they (the mass media
bureau) still hasn't gotten around to converting, but they had no problem
going metric did they?

And while I'm speaking of CDBS, there is no "official" database of
facilities for mass media - CDBS is the database we all use (both inside and
outside the Commission), but it has not been codified as the "official"
database or source - in spite of various requests to do so.  One need look
no farther than the number of errors to understand why this is -  after 12
years of operation it still has errors buried deep within it. 

The FCC maintains that that the databases (all of them) are unofficial
listings prepared for the convenience of the Commission and should not be
relied upon by the public because of cases in which the database may not
match up with official sources of information, including official license
documents or actual applications.

TZS

>>-------------------------------------------------<<
>With regard to NAD27, keep in mind that according to the FCC the internal
algorithm to convert from NAD83/WGS84 to NAD27 does not have acceptable
>accuracy.  See the footnotes to the Public Notice at the following URL:

>http://transition.fcc.gov/ftp/Bureaus/Mass_Media/Databases/documents_collec
tion/da88-316.html

>Even though this Public Notice is from 1988, based on a phone conversation
I had with the listed contact person, Donald Campbell, in April 2009 it
>still applies to "consumer" grade GPS's.  Only the professional grade GPS
units (read costing multiple thousands of dollars) have sufficiently
>accurate internal conversion routines.

>Regards,
>Alan