For FAA Obstruction Evaluations only and this is where the 2C survey requirement applies. FCC has its own set of rules and requirements..
From FAA FAQs on filing FAA Form 7460-1: 12. How do I get the latitude and longitude? The geographic coordinates may be obtained by utilizing a U.S. Geographical Survey (USGS) 7.5 minute quadrangle map or equivalent, a GPS receiver, a certified survey or other available mapping source. The coordinates must be converted to the degrees, minutes, seconds to the hundredth of a second format. The coordinates should be accurate to within the nearest second or hundredth of a second. If a certified survey is available, please submit it with the study. And from the Survey Accuracy Tab: Survey Accuracy Experience has shown that submissions often contain elevation and/or location errors. Current directives require the FAA to apply accuracy standards to obstacles when evaluating effects on instrument procedures. These accuracy standards typically require a 4D adjustment of 250 feet horizontally and 50 feet vertically to be applied in the most critical direction. Normally, these adjustments are applied to those structures that may become the controlling obstructions and are applicable until their elevation is verified by survey. In these instances, the acceptable accuracy verification method will be requested by the FAA to pursue a favorable determination. A licensed engineer or surveyor must certify the provided survey accuracy and include the plus or minus accuracy required, as well as, the signature of the engineer/surveyor and the appropriate seal. A final determination based on improved accuracy shall not be issued until after the certified survey is received. The following Obstacle Accuracy Codes are applied in accordance with FAA Order 8260.19H, Appendix C. HORIZONTAL VERTICAL Code Tolerance Code Tolerance 1 +20 ft (6 m) A +3 ft (1 m) 2 +50 ft (15 m) B +10 ft (3 m) 3 +100 ft (30 m) C +20 ft (6 m) 4 +250 ft (75 m) D +50 ft (15 m) 5 +500 ft (150 m) E +125 ft (38 m) 6 +1,000 ft (300 m) F +250 ft (75 m) 7 +1/2 NM (900 m) G +500 ft (150 m) 8 +1 NM (1800 m) H +1,000 ft (300 m) 9 Unknown I Unknown During the aeronautical study process, the FAA may request a certified survey with an accuracy of either 1A (+20 ft horizontally +3 ft vertically) or 2C (+50 ft horizontally +20 ft vertically). > On Dec 28, 2020, at 12:01 PM, Ken Hohhof <[email protected]> wrote: > > When I had our frequency coordinator do an FAA application for us (licensed > link on tower near airport) and mentioned the discussion here about 2C > surveys, they acted like I was crazy. Are you sure this is required? > > Steve, is this hypothetical, or is the FCC paying you a visit? > > I know one time I discovered the commercial tower we were on had the lat/lon > wrong on the ASR. For us to fix out license, they had to also fix the ASR. > It was just a matter of filing a modification. I also seem to remember > something about it wasn’t significant unless it was off by at least 1 second > or something. > > Honestly I just use the numbers from my Garmin 64st, same as for CPI data for > CBRS. Given several minutes it will usually state accuracy within <10 feet. > I check it against Google Earth and they usually match to better than that. > Even the elevation AMSL usually matches. If there was a need for a survey I > would think it would have to be for AMSL, there’s just no rational reason to > need a surveyor to certify the lat/lon these days. > > > From: AF <[email protected]> On Behalf Of Steve Jones > Sent: Monday, December 28, 2020 10:41 AM > To: AnimalFarm Microwave Users Group <[email protected]> > Subject: Re: [AFMUG] FCC coordinate verification > > im asking about if you get nailed by the FCC, not application > > On Mon, Dec 28, 2020 at 10:13 AM Cameron Crum <[email protected] > <mailto:[email protected]>> wrote: >> Typically if you are filing for FAA or FCC you have to supply coordinates >> from a 2C survey mimium. They assume a certified survey is good enough. >> >> >> On Mon, Dec 28, 2020 at 10:02 AM Steve Jones <[email protected] >> <mailto:[email protected]>> wrote: >>> Have any of you guys ever had the FCC verify your transmitter data? >>> What equipment do they use to verify elevation and coordinate? >>> -- >>> AF mailing list >>> [email protected] <mailto:[email protected]> >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> <http://af.afmug.com/mailman/listinfo/af_af.afmug.com> >> -- >> AF mailing list >> [email protected] <mailto:[email protected]> >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> <http://af.afmug.com/mailman/listinfo/af_af.afmug.com>-- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com
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