Physical Fundamentals This attenuation is usually expressed in decibels(dB). By definition, an attenuation of n db means that the original field strength is decreased by a factor of 10-0.In Physical quantities Quantity Symbol Dimension Circular frequency wavelength λP m/cvcle Speed of light m Principles of the Global Positioning System 20053-18(5 Integer cycles are equivalent to multiples of 2T radians Another unit for cycles per second(cps )is Hertz(Hz) ∫=2nn= By Phase 0=m=0(=6)=0=2 Example Known: F=1.5GHz, c=3x10 km/s, D=20,000km Question: cycles=?(10), Observable=? Principles of the Global Positioning System 20053-18(63 Principles of the Global Positioning System 2005-3-18 5 Physical Fundamentals This attenuation is usually expressed in decibels (dB). By definition, an attenuation of n dB means that the original field strength is decreased by a factor of 10-0.1n. Principles of the Global Positioning System 2005-3-18 6