hydrocast depth, and the lower portion contains ogives of the set of positive and the set 

 of negative differences. By coincidence, more of the differences are positive than negative 

 for both sets of data, since the sign of the difference depends on which system is arbitrarily 

 chosen as the reference. 



Table 44 lists pertinent statistics for the above-, in-, and below-thermocline subsets 

 of differences, as well as for the set of all differences. Listed are the number of differences, 

 the average difference and its standard deviation, and the percentage of differences that 

 exceeded ±0.34°C. The most accurate temperature measurements are made above the 

 thermocline, where vertical temperature gradients are small or nonexistent. As shown in 

 table 44, for the 223 ORB-3 measurements made above the thermocline, the average differ- 

 ence was 0.09°C, with a standard deviation of 0.18°C. For the 180 RAPLOC/DEEPTOW 

 measurements, the comparable numbers are 0.08°C and 0.1 4°C, respectively. In the ORB-3 

 subset, 71 .4% of the differences were positive and 24.7% negative. The comparable percent- 

 ages for the RAPLOC/DEEPTOW subset were 71 .1% and 24.4%, respectively. 





ORB-3 



RAPLOC/DEEPTOW 



ABOVE THERMOCLINE 







Number of differences 



223 



180 



Average, °C 



0.09 



0.08 



Standard deviation, °C 



0.18 



0.14 



Percent: 







Greater than +0.34°C 



7.6 



3.9 



Less than -0.34°C 



<0.1 



<0.1 



IN THERMOCLINE 







Number of differences 



134 



179 



Average, °C 



0.18 



0.11 



Standard deviation, °C 



0.34 



0.44 



Percent : 







Greater than +0.34°C 



25.4 



21.2 



Less than -0.34°C 



3.0 



6.1 



BELOW THERMOCLINE 







Number of differences 



186 



214 



Average, °C 



0.06 



0.07 



Standard deviation, °C 



0.33 



0.43 



Percent: 







Greater than -K).34°C 



15.6 



8.4 



Less than -0.34°C 



9.1 



3.7 



ALL DIFFERENCES 







Number of differences 



543 





Average, °C 



0.10 



0.08 



Standard deviation, °C 



0.29 



0.37 



Percent: 







Greater than +0.34°C 



14.7 



11.0 



Less than -0.34°C 



4.1 



3.5 



Table 44. Comparison of simultaneous XBT profiles taken during the ORB-3 

 and RAPLOC/DEEPTOW experiments. 



105 



