Fraser fir this purpose. Fraser fir has been used more times as the White House Christmas tree (the official Christmas tree of the President of the United States's White House) than any other tree. It is grown in plantations in Scotland and sold by the thousands throughout the United Kingdom and Ireland. It is also cultivated from seedlings in several northern states in the USA and adjacent parts of Quebec province, especially for the Christmas tree trade. The combination of form, needle retention, dark blue-green color, pleasant scent and excellent shipping characteristics has led to Fraser fir being a most popular Christmas
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.