I 



cast and the airborne IRT, it is recommended that known reliable surface observations be 

 obtained when over key points and the chart temperature grid adjusted to a known observa- 

 tion for readout. 



Experience indicates that to obtain the best operating results with the model 14-312 

 or IT-2 IRT the instrument's detector head should: 1. be located out of any turbulent air 

 currents — preferably several inches to a foot or more from any opening, 2. recycle times 

 of the detector temperature reference source when mounted in the aircraft should be approxi- 

 mately the same as those observed in the laboratory; however, small fluctuations in the 

 temperature record have been observed when the detector was placed near a source of tur- 

 bulence, even though recycle times were approximately the same as experienced in the 

 laboratory, 3. be loosely shock-mounted and the console be provided with a shock pad. 



Interference from UHF transmitters has been observed, and when near some military 

 installations or ships, an increase in erratic behavior of the IRT has been noted. On some 

 occasions a shifting aircraft vibration frequency, such as a change in propeller pitch, 

 appears to affect the IRT. This sometimes can be eliminated by dampii^ the instrument 

 case. 



Haze observations indicate a decrease in temperature of an estimated 0.68° F. per 

 1000 feet at a surface visibility estimate of six miles. Low. thin scattered stratus appears 

 not to have an observable effect on the airborne IRT readout. 



Rain showers sometimes cause a reduction in IRT temperature readout. The effect 

 probably is dependent upon the relationship of the rain temperature to the water temperature. 



Air temperature isotherms from observations made at 500' M.S.L. in most areas 

 appear not to parallel sea surface isotherms. IRT isotherms sometimes appear to parallel 

 wind flow patterns around prominent geographical points of the mainland as observed off 

 Pt. Conception and Santa Barbara channel islands. Parallel isotherm and wind flow patterns 

 appear more evident in areas having higher wind velocities. In offshore areas there appears 

 little paralleling of wind flow and isotherms. 



Anon. 



Anon. 



REFERENCES 



1962. Application Note 14-0300-1, Sea Surface Temperature Plotting with Model 

 14-312 Radiometer, Barnes Engineering Company. Stamford, Conn.. 5 p. 



1963. Pacific Coast continental shelf temperature survey, southern area, November. 

 Correction values for infrared sea surface charts - August to October 1963. Tiburon 

 Marine Laboratory, Tiburon, California, 1 p. 



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