USE OF THE BARNES MODEL 14-320 AIRBORNE RADIATION THERMOMETER IN 

 AERIAL SURVEYS OVER THE NORTH ATLANTIC 



by Robert A. Peloquin, John C. Wilkerson and George L. Hanssen, 

 U. S. Naval Oceanographic Office, Washington, D. C. 



INTRODUCTION 



Sjmoptic analysis, an important tool in forecasting vertical and horizontal thermal ■ 

 structure of the ocean and their effects on ASW equipment performance, is being developed 

 for operational use by the Navy under the Antisubmarine Warfare Environmental Prediction 

 System (ASWEPS). The airborne radiation thermometer (ART), Barnes model 14-320, has 

 been used experimentally by the U. S. Naval Oceanographic Office to determine the value of 

 infrared sea surface temperature measurements as synoptic information. 



ART data are being used in surface temperature analyses and in construction of sea 

 surface temperature charts. The instrument, developed by the Barnes Engineering Companj 

 of Stamford, Connecticut, is packaged in a console designed to fit over the camera hatch of 

 a P2V. The ART measures sea surface temperature over a range of -2° to +35 °C with an 

 accuracy of ±0.2°. 



TECHNICAL ASPECTS OF THE ART 



Instrument Accuracy 



In the laboratory, the ART has consistently demonstrated ability to measure water 

 temperature to within ±0.2°C, A temperature-controlled water bath and a mercury therm- 

 ometer are used for calibration. Calibration is a long process which can normally be per- 

 formed in one day. The field accuracy of the ART is more difficult to determine. The ART 

 measures the temperature of a 0.01 mm layer at the surface. At present, there are no 

 standards which can successfully measure this layer. Comparative measurements with 

 thermistors, bucket thermometers, and reversing thermometers, on some occasions, have 

 been within 0.5°C. On other occasions, as much as 3.0°C deviation has been noted. En- 

 vironmental influences may have very pronounced effects on infrared measurements. Of the 

 comparative measurements made to date, the best agreement was obtained in the Tongue of 

 the Ocean and Bermuda areas, where the air-sea temperature difference was close to zero. 

 The largest discrepancies occurred in the Gulf Stream when the air-sea temperature differ- 

 ence was of the order of 10°C. 



The instrument is restricted to fair-weather operation. Precipitation, low cloud 

 ceilings, haze, and sea states of 6 or higher hamper ART operations. 



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