Anemometer beam exits reflect, or backscatter, the light back into a detector, where it is measured relative to the original laser beam. When the particles are in great motion, they produce a Doppler shift for measuring wind speed in the laser light, which is used to calculate the speed of the particles, and therefore the air around the anemometer. Ultrasonic anemometers, first developed in the 1950s, use ultrasonic sound waves to measure wind velocity. They measure wind speed based on the time of flight of sonic pulses between pairs of transducers. Measurements from pairs of transducers can be combined to yield
Measure S and the quote "I Agree". The other showed a letter written by him on city letterhead, with "I agree" following many pro-Measure S talking points. It was headed "Mayor Garcetti finds a lot to like about Measure S". The mailer implied that Garcetti supported Measure S, which in fact he strongly opposed. He called it a "dirty trick". A CPLA spokesperson said in response that "[t]his was just a friendly reminder on what these City Hall insiders promised and what they've yet to deliver to the voters of Los Angeles." A week before the vote, an editorial in the "Los