AUTOMATIC WEATHER STATION (GRASSHOPPER) PART I DESIGN AND MODIFICATIONS 1955-1961.
NAVAL RESEARCH LAB WASHINGTON D C
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Weather information is required from critical areas where routine meteorological observations are not made or can be made only at considerable expense. An automatic weather station Grass hopper was developed which is capable of telem etering data from a 15-watt input to the final transmitter over distances of hundreds of miles every six hours for several months. The initial models were air deliverable, but in 1959 NRL removed the parachute capability to make it a manual-delivered land station. Present models of this station contain sensors for wind direc tion, wind speed, air temperature, and barometric pressure. The station transmits in international Morse code in three-letter groups at a word rate of 17 groups per minute which is satisfactory for monitoring by conventional receiving equip ment. The received Morse code is converted to weather data by calibration charts supplied with each station. The accuracy of the transmitted weather data is equivalent to a manned station. In addition to the meteorological variables, the station sends its identifying call. Com merically available equipment was used in design and manufacture whenever possible to take ad vantage of lower costs, easier replacement of parts, and greater reliability. Autor