Christmas tree Macy's Great Tree in Atlanta (since 1948), the Rockefeller Center Christmas Tree in New York City, and the large Christmas tree at Victoria Square in Adelaide. The use of fire retardant allows many indoor public areas to place real trees and be compliant with code. Licensed applicants of fire retardant solution spray the tree, tag the tree, and provide a certificate for inspection. Real trees are popular with high end visual merchandising displays around the world. Leading global retailers such as Apple often place real trees in their window displays. In 2009, Apple placed two Fraser fir trees in every
Fraser Filter Fraser Filter A Fraser Filter, named after Douglas Fraser, is typically used in geophysics when displaying VLF data. It is effectively the first derivative of the data. If formula_1 represents the collected data then formula_2 is the average of two values. Consider this value to be plotted between point 1 and point 2 and do the same with points 3 and 4: formula_3 If formula_4 represents the space between each station along the line then formula_5 is the Fraser Filter of those four values. Since formula_6 is constant, it can be ignored and the Fraser Filter considered to be formula_7.