APPENDIX A: SUBROUTINE WEDGE 



1. Subroutine WEDGE is used to calculate the value of <f> in Equa- 

 tion 26 which is generally a complex number. Its absolute value is the ampli- 

 fication factor, and its phase is the phase indicator from the phase of the 

 incident wave. As mentioned in the main text, $ is a function of the Bessel 

 function of either fractional or integer order, depending on the wedge angle, 

 and is the summation of a series of infinite terms. The subroutine BESJ, doc- 

 umented in the Naval Surface Weapons Center (NSWC) Library of Mathematics Sub- 

 routines (Morris 1984)* is used in the WEDGE subroutine. The programming of 

 the WEDGE subroutine is very straightforward if a truncation term in the se- 

 ries in Equation 26 is determined. The program is written in FORTRAN language 

 and is listed in this appendix. 



Description 



2. The following subroutine is available for computing (j) in 

 Equation 26: 



CALL WEDGE (F,FABS,FPHA,XRL,XTH,WEDGEA,WAVEA,IDX) 



where the arguments are all real values except F which is a complex value. 

 Input arguments are as follows: 



a. (XRL,XTH)=(r/A,9) where (r,6) are polar coordinates of the lo- 

 cation where <|> is to be computed, and \ is the incident wave 

 length. Therefore, XRL is the radius vector or radius distance 

 normalized by the incident wave length. XTH is the vectorial 

 angle in degree. 



b. WEDGEA = wedge angle in degree. 



c. WAVEA = incident wave angle in degree. 



d. IDX = an index (set to in this subroutine) . 

 Output arguments are as follows: 



* References cited in the Appendix can be found in the References at the end 

 of the main text. 



Al 



