14 Jan  2005    News for NTIA/ITS HF Propagation Models (WINDOWS version)

14 Jan  2005   1. This version should only affect REC533.
                  I added a change requested by the ITU Working Party 3L.
                  And I quote from the request (Document-3/40-E)(27 Oct 2004):
                        Introduction
                    For the F2 region, the inter-decile range of the operational
                    MUF is taken to be 0.85-1.15 of the monthly median value.
                    This procedure was originally adopted as a simple method
                    suitable for multiple calculations. This restriction no
                    longer applies and a more accurate description of the
                    distribution of operational MUF with location, season and
                    time of day can be inserted.

                         Proposal
                    It is proposed the Recommendation ITU-R P.533, Section 3.6
                    should be amended to replace the single value for the
                    lower decile factor by the values given in 
                    Recommendation ITU-R P.1240, Section 7, Table 2.

                  I have replicated Table 2 and that may be found in the
                  file ..\database\p1240.dat.
                  This is the file that is read to fill the array values,
                  so do not change it, unless you find an error.

               2. Be aware that the above change only affects the output
                  variable named FOT. This is known as the Operational MUF.
                  The variable named MUF is the Basic MUF and is not affected.
                  If those who proposed the change would like to discuss this
                  with me, they should contact me by email(cbehm@its.bldrdoc.gov).

               3. The current source code for VOACAP & REC533 has been updated
                  and is available from the website.

               4. My retirement is set for 3 Feb 2005. I will continue to
                  be involved with the software from home.