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WEATHER BUREAU RESEARCH AIRCRAFT 



The four Weather Bureau research aircraft arrived in Bombay on April 30, 1963 

 for a three-month period of gathering data needed to describe the onset of the 

 Indian Ocean monsoon. They departed from Bombay on July 18, 1963. A second 

 expedition of two aircraft in January to March, I96U made similar measurements 

 during the quiet season. 



The Weather Bureau research aircraft consist of two DC-6a.'s, one W-57A, and 

 one W-26. All are equipped with special meteorological probes and recorders 

 for gathering meteorological data needed for research. 



The two DC-6A/B aircraft (converted Douglas transports with four 

 reciprocating engines) are' equipped with Doppler navigation systems 

 (AFN-82) used to determine positions and automatically compute 

 flight level winds. Temperatures are measured with the vortex 

 thermometer (AMQ-8) and a high- response Rosemont probe. Humidity 

 measurements are made by an infra-red hydrometer. D-Values are 

 determined from precision pressure transducers and radio altimeter 

 systems. Three weather radar sets are installed -- a 10 cm radar 

 for scanning at ranges up to 250 miles, a 5.6 cm nose radar with 

 ranges up to 150 miles, and a vertical scanning radar operating 

 flight conditions are recorded. Data is recorded digitally on 

 magnetic" tape with backup data recording photographically. Time 

 lapse cameras record cloud forms. 



The W-57 aircraft is a twin jet engine aircraft capable of 

 operating up to 50,000 feet. The parameters recorded and methods 

 of recording on this airplane are essentially the same as on the 

 DC- 6, except the humidity measurements are omitted and only one 

 weather search radar operating on 3.2 cm is used. 



The W-26 aircraft is a twin reciprocating engine airplane capable 

 of operating up to altitudes of about 24,000 feet. A Doppler 

 system is used for position determination, and the computation 

 of flight level winds. Measurements of humidity, temperature, 

 radar altitude and pressure altitude are made. Recording is made 

 on a continuous strip by an oscillograph. A 5»6 cm weather radar 

 is used and the scope is photographed. 



The data collection program carried out by these aircraft during the three- 

 month period was adjudged by all to be highly satisfactory. Large amounts of 

 unique and essential data were accumulated, which are now being evaluated and 

 processed at the International Meteorological Center at Bombay. 



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