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XX;7A"LH E N N E P I N WES T M E S 0 N E T <br />Frequently Asked Questions <br />Q: Who operates the HennepinWest Mesonet? <br />A: Hennepin County Emergency Management, with the guidance of an advisory board made up of many <br />other departments and agencies. <br />Q: Why are existing weather stations not adequate? <br />A: The overall number of surface stations in the Metro area today is too small to provide the fine detail <br />optimal for many public warning decisions. The locations of most existing stations are at public airports <br />or along interstate highways so data is not relevant for people and facilities located away from these <br />stations. Many stations were set up to report climate information that is old (up to one hour) rather <br />than up to the minute real-time data, which makes them nearly useless in warning and evacuation <br />situations. Networked private stations are often located poorly and can get erroneous readings for <br />winds or temperatures. Few of these stations are ever calibrated or maintained using strict operational <br />accuracy standards which may also lead to unreliable measurements. <br />Q: Can't other tools, such as Doppler radar, do the same job? <br />A: No. Doppler radar is a fantastic tool, and has been made even more useful after recent upgrades <br />made by the National Weather Service, however there are some things that radar cannot do at all, <br />cannot do as well, or cannot do as quickly. Some of these shortfalls relate to the length of time that <br />Doppler needs for a single scan —five minutes. Another is that the radar beam cannot see the surface <br />due to the curvature of the Earth, so a Doppler radar picture actually shows what is taking place a <br />thousand or more feet in the air. Hazardous material incidents require surface wind measurements to <br />accurately model. Finally, when areas are very close to the radar site, ground clutter or other radar <br />beam characteristics can degrade performance near the surface. Mesonet stations and radar <br />complement each other and can be used together to develop accurate real-time situational awareness. <br />Q: Is the Mesonet station structure an antenna? <br />A: No. An antenna is defined as a conductor or system of conductors used for either radiating <br />electromagnetic energy into the atmosphere or for collecting electromagnetic energy from the <br />atmosphere. The station structure itself does not collect or broadcast any electromagnetic energy. <br />However, when cell phone signals are used to convey data from sensors to the database a tiny cell <br />phone antenna no larger than one on a personal cell phone is used. <br />