4.1 Method 4-1. Upgoing wave reflection at solid boundary, single transducer deconvolution using delay equation, no mud pump noise (Software reference, XDUCER*.FOR).4.2 Method 4-2. Upgoing wave reflection at solid boundary, single transducer deconvolution using delay equation, with mud pump noise (Software reference, HYBRID*.FOR).4.3 Method 4-3. Directional filtering – difference equation method requiring two transducers (Software reference, 2XDCR*.FOR).4.4 Method 4-4. Directional filtering – differential equation method requiring two transducers (Software reference, SAS14D*.FOR, Option 3 only).4.5 Method 4-5. Downhole reflection and deconvolution at the bit, waves created by MWD dipole source, bit assumed as perfect solid reflector (Software reference, DELTAP*.FOR).4.6 Method 4-6. Downhole reflection and deconvolution at the bit, waves created by MWD dipole source, bit assumed as perfect open end or zero acoustic pressure reflector (Software reference, DPOPEN*.FOR).4.7 References.