Section C. SUBROUTINES USED IN THE PROGRAM 



1. BENLH2 - Plotting Subroutine 



Subroutine BENLH2 performs the operations necessary to produce 

 a plot of the trackline and of the radiation data on the Benson-Lehner 

 incremental plotter. BENLH2 does this by calling the several subroutines 

 of the Benson-Lehner plot package which translates the data given" to the 

 subroutines by BENLH2 into plot commands that are written out onto mag- 

 netic tape. The tape is used to drive a Benson-Lehner model 305 incre- 

 mental plotter off-line. Figure 2 is a flow chart of this subroutine. 



Subroutine TRACK is substituted for subroutine BENLH2 to produce 

 the RAPLOT III program. TRACK interfaces the RAPLOT program with the 

 plot subroutines for the Stromberg- Carlson 4060 cathode ray tube. Other- 

 wise, it functions essentially like subroutine BENLH2. Both subroutines 

 plot the trackline followed by the survey vessel, and both will also plot 

 the uncorrected or corrected radiation values for each survey. These are 

 symbol plots in which the count rate is represented by a symbol indicat- 

 ing a value between arbitrarily fixed limits. For uncorrected radiation, 

 the limits are established in terms of standard deviation from the mean 

 background count rate. For corrected radiation count rate, the internal 

 limits for each symbol are established on a power of 2 scale. Also, a 

 special symbol is used to indicate background if the count rate is less 

 than 3 standard deviations from the background count rate. If the count 

 rate is more than 3 standard deviations below background, the value is 

 not plotted at all. The reason for this is that an abnormally low count 

 rate may indicate that the detector was "flying" meaning that it was not 

 in contact with the ocean bottom at the time of the fix. Both BENLH2 

 and TRACK will plot the location of the mean radiation position referred 

 to as RADBAR. They may also plot the location of the injection site, if 

 this is desired. 



2. Statistical Subroutines 



The subroutines described below are used to perform certain sta- 

 tistical computations required by the RAPLOT II program. To reduce the 

 time necessary to prepare the program, these subroutines were taken from 

 the STAT-PACK, a library of statistical subroutines available on the 

 UNIVAC 1108 system. Further details may be obtained from the STAT-PACK 

 Programmers' Reference Manual. 



Subroutine STDEV computes the standard deviation of an array by 

 the following formula: 



I CX± - x) 



i=l 



a/2 



