FAA issues voluntary MET code

The US FAA has issued recommended guidance for the voluntary marking of Meteorological Evaluation Towers (METs) erected in remote and rural areas that are less than 200 feet above ground level (AGL).
This guidance will enhance the conspicuity of the towers for low level agricultural operations in the vicinity of these towers.
The FAA has been approached by operators, associations representing agricultural operators, and state governments concerning the visibility of METs in remote and rural areas that also have low-level flight operations.
METs are used by wind energy companies to determine feasible sites for wind turbines.
Some of these towers are less than 200 feet AGL, usually at 198 feet or less. The structures are portable, erected in a matter of hours, installed with guyed wires and constructed from a galvanized material often making them difficult to see in certain atmospheric conditions. The METs that fall under the 200 foot AGL threshold are not subject to notice requirements and do not trigger any aeronautical study by the FAA.
Read the report at: http://www.federalregister.gov/articles/2011/06/24/2011-15746/marking-meteorological-evaluation-towers