Sensor 



GULF OF ALASKA 



SUDS I 



CAPER 



RAPLOC/DEEPTOW 



Hydrocast 



- 



6 



3 



- 



STD/SV 



44 



7 



22 



17 



Towed thermistor 



327 



- 



- 



- 



Thermistor chain 



- 



160 



- 



- 



Bucket thermometer 



- 



- 



138 



71 



TOTALS 



371 



173 



163 



88 



Table 26. Summary of XBT surface temperature measurement 

 accuracy data base. 



During the Gulf of Alaska experiments, 334 visually acceptable XBT profiles were 

 obtained while the towed thermistor measurements were being made. For seven of the 

 334 profiles, the calibration line exceeded ±0.34°C, leaving 327 visually acceptable profiles. 

 Comparison of the XBT surface temperatures with the towed thermistor temperatures 

 showed that the XBT system began to malfunction when making XBT profile 166. Of a 

 total of 327 profiles, the accuracy of the XBT surface temperature was questionable for 

 162 profiles (49.5%). 



The second system, used by the MOAN A WAVE during the CAPER experiments, 

 made 138 visually acceptable XBT profiles. At the time these measurements were made, 

 independent surface temperature measurements were also made with a bucket thermometer. 

 As in the case of the Gulf of Alaska measurements, the comparisons showed that the 

 MOANA WAVE XBT system began to malfunction after XBT 45. The 103 surface temper- 

 atures recorded by the profiles made after profile 45 were all in error (74.6%). 



The cause, or causes, of the malfunctions are not known. The malfunction of the 

 two systems would not have been discovered if independent surface measurements had not 

 been made. 



Table 27 and figure 26 summarize pertinent statistics of the surface temperature 

 comparisons for the profiles made when the systems were not malfunctioning (designated 

 as profile set I)*; for the profiles made when the LEE (Gulf of Alaska) and the MOANA 

 WAVE (CAPER) systems were malfunctioning (designated as profile set II)*; for all visually 

 acceptable Gulf of Alaska and CAPER profiles; and for all 736 visually acceptable profiles. 



*Profile Set I and Profile Set II are subsets of the set of all visually acceptable XBT profiles. These sets are 

 defined as follows. 



Profile Set I : 



Profile Set II: 



All visually acceptable XBT profiles made when an XBT system was not malfunctioning, as 

 determined from a comparison of XBT surface temperatures with independent measure- 

 ments of surface temperature. 



All visually acceptable XBT profiles made when an XBT system was malfunctioning, as 

 determined from a comparison of XBT surface temperatures with independent measure- 

 ments of surface temperature. 



60 



