This directory (AT/RAM if installed correctly) contains the most recent version of the RAM PE (Parabolic Equation) acoustic propagation model written by Michael Collins of NRL, with some minor modifications by HLS. A short summary of the modifications can be found in the file named "diffs_re_nrl.txt". The original, unmodified code was obtained from the NRL ftp server at; ftp://ftp.ccs.nrl.navy.mil/pub/ram/RAM/ Because RAM is not an integral part of the HLS Acoustics Toolbox, building it is a separate task. There is a single FORTRAN source file named "ram.f" that needs to be compiled to produce an executable file "ram.exe" which should then be copied into the ../bin directory. This can be done manually as shown below or if you have a make utility by using the provided Makefile gfortran -o ram.exe -Os ram.f copy ram.exe ..\bin If you use the provided Makefile, it will likely require customization to reflect which FORTRAN compiler you have. Edit the Makefile, and modify the assignment to FC to reflect your FORTRAN compiler (the full path to the compiler may be required depending on how it was installed). The FFLAGS variable may also need to be modified to specify the compiler flags for the desired level of optimization which is compiler dependent in general. For g77 or gfortran, either -Os or -O2 work well.