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All    1995    News for NTIA/ITS HF Propagation Models
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09 Jan 1995    1. VOACAP & ICEPAC have been changed so that the default 
                  Man-Made NOISE levels correspond to the new CCIR accepted
                  levels as defined in CCIR Report 258 below:
                            1 = -140.4 dBW = Industrial (Business)
                            2 = -144.7 dBW = Residential
                            3 = -150.0 dBW = Rural
                            4 = -163.6 dBW = Remote

               2. All models have been changed so that each time it is executed,
                  the parameters that are read as the current data is by the
                  following order:
                      1. Read "..\RUN\model.BIN" if it exists.
                      2. ELSE read "..\SAVED\DEFAULT\DEFAULT.model"
                                   "..\AREADATA\DEFAULT\DEFAULT.model" (area)
                      3. ELSE use internal defaults
                 Previously, step 2 above did not exist.
                 This way, each organization can create their own DEFAULT data
                 file the way they want it.

               3. Check out the HELP file HISTORY1 under ITSHF for a brief
                  historical letter on HF models at ITS up to 1978.
                  I will try and create one for 1978-present.

               4. All models have been modified so that the same coefficient
                  files are used.  The coefficients were all the same except
                  when the URSI 88 coefficients for foF2 were used in ICEPAC.
                  All models now have the option to use the URSI 88 foF2
                  coefficients.  REC533 does not use many of the coefficients,
                  therefore, they have been re-ordered to put those values used
                  by REC533 at the end.  The ASCII coefficient files have been
                  annotated with text so that they are no longer a mystery.
                  It is SUGGESTED that you SHOULD use the URSI 88 coefficients
                  as they were created with data over the oceans and the
                  curve fit by SSN was corrected so as to not be a problem
                  for SSN > 180.

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22 Feb 1995    1. ICEPAC has been modified so that for method 25 (ALL MODES),
                  the final column now has the title "Most REL" to indicate
                  that this is the most reliable mode.  Previously, this was
                  assumed.

               2. SNR calculations in ICEPAC and VOACAP have been corrected
                  under contract by Don Lucas.  It was previously felt that
                  the signal and noise distributions were combined incorrectly.
                  It has now been changed to be more technically correct.

               3. Additionally, the output parameter FDAYS has been renamed
                  to MUFday.  It is the percent of days of the month that the
                  HOP MUF is predicted to occur.

               4. A post-processor for area coverage maps has been developed.
                  You will notice a new option in the area coverage programs
                  that is titled "cOmbine maps".  This allows you to 
                  mathematically combine map grid files using operators such
                  as: MINIMUM, MAXIMUM, AVERAGE, POWERSUM, SUBTRACT, MEDIAN,
                  DECILExx.

               5. All AREA COVERAGE programs (ICEAREA, VOAAREA, RECAREA) have
                  been modified so that you may specify the FREQUENCY =0.
                  What this will do is run the frequency complement defined in
                  ..\RUN\AREAFREQ.DAT (or ..\DATABASE\AREAFREQ.DAT) and save
                  the maximum value of the parameters [DBU SDBW SNR REL SPROB
                  SNRxx] and write them to the grid file (*.mG?).  This allows
                  efficient analysis of coverage areas where multiple
                  frequencies are allowed.

               6. Area coverage transmitter main beam bearing can now be = -1,
                  which will identify the transmitter as an omni-directional 
                  antenna.  Therefore, the tranmsitter location can be 
                  identified without the main beam direction being drawn.

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14 Mar 1995    1. A driver has been written for HP DeskJet 5xxC series color
                  printers.  The default color driver supplied will work for
                  HP PaintJet and HP PaintJet XL printers.
                  To change to the color printer driver,
                  while in the ..\RUN directory, type:
                     DESKJET   - for HP DeskJet driver for x3 pixel expansion.
                     DESKJET4  - for HP DeskJet driver for x4 pixel expansion.
                     PAINTJET  - for HP PaintJet (& XL) driver.

                  If the printer is not on the LPT1 port, change the file:
                     ..\BIN\HPXLDMP.BAT to reflect the correct port.
                  Similarly, the file ..\BIN\HPJETDMP.BAT controls output to
                  the LaserJet printer.
                  Black/White output formatted for a LaserJet printer is
                  compatable on DeskJet and PaintJet printers.

27 Mar 1995    1. In the area coverage input programs(ICEAREA,VOAAREA,RECAREA),
                  the minimum angle is supposed to default to 3 degrees if you
                  set it to 0.  The program would not let you set a value below
                  .01 degrees.  That has been fixed.

               2. The COMBINE program for area coverage maps continues being
                  enhanced.  A S/I operation and a BIN (turn ranges into
                  discrete values) have been added.  Also, since COMBINE
                  allows you to combine the output from many area coverage
                  calculations, there may be many transmitters used.  When
                  you plot the resultant plot, only 1 transmitter was being
                  plotted.  Now all of the tranmitter locations are saved
                  on a file (named ********.mXT), where m=[I,V,R for model].
                  This file is then read by the plotting program if it exists,
                  and all of the transmitter locations are marked and their
                  main beam directions are drawn.  Remember, if the antenna
                  is non-directional, set its main beam direction to -1.

               3. A simple method has been developed to allow you to configure
                  you printer port, and also choose between color printer
                  drivers.  If you begin program execution with ITSHF, there
                  is a new option called SETUP (Set up printer ports).
                  If you have configurations that are not allowed, please
                  Email me your specifics.

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11 Apr 1995    1. A correction was made to HFANT. 
                  Type 12 antennas (NTIA 87-215 Curtain arrays) did not
                  produce the correct directivity gain on the plot.  The
                  gains in the propagation routine were correct.
                  This has been corrected.

28 Apr 1995    1. COMBINE was changed so that you do not require to specify
                  both the *.mCB filename and the *.mG1 filename.  Now
                  you only specify one, and both are named the same.
                  Since I always suggested you use the same name, this now 
                  forces that and makes it simpler.

               2. IONCAP antenna type HORIZONTAL-DIPOLE had a problem where
                  the gain at 90 degrees elevation angle was a function of
                  the off-azimuth angle.  Since 90 degrees is straight up,
                  the answer should be the same.  That appeared to be a
                  function of the internal equations.  They do not converge
                  when logically they should.  To make the result consistent
                  at 90 degrees elevation angle, I changed the gain routine
                  to produce the same answer.  However, it produces quite a
                  difference at 89.5 degrees.  If anyone has better gain
                  calculation for Horizontal-Dipoles, please send it and I
                  will incorporate it.

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12 May 1995    1. The area coverage input screen was changed to allow for
                  non-directional receive antennas.  It was previously
                  assumed that all area coverage calculations were performed
                  using non-directional receive antennas.  However, a user
                  requested the ability to model a directional antenna.
                  A sample of that might be an antenna on board an aircraft.
                  Of course, in this application, you must view the output
                  map with some knowledge of the flight path of the aircraft.
                  See the HELP file REC_BEAM under the area coverage programs
                  for more information.

               2. The default colors used for drawing Point-to-Point graphs
                  exists in the file ..\DATABASE\COLORS.GPH.
                  This allows users to select the colors of their choice.

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01 Jun 1995    1. Area coverage calculations may now be performed using
                  either the GREAT CIRCLE projection (previously the only
                  option), or in Cylindrical Latitude/Longitude coordinates.
                  This was added to allow the data to be converted into GRIB
                  format as was required by a sponsor.  If data is to be
                  converted to the GRIB format, one of the predefined
                  latitude/longitude projections must be used.  These are
                  identified numerically as [21,22,23,24].  Other users can
                  specify the projection type [1] and specify any latitude/
                  longitude coordinates desired.  The Great Circle projection
                  is the normal default used and it is identified a projection
                  type [0], which allows old data files to require no changes.

                  Cylindrical Latitude/Longitude coordinates can allow users
                  to perform calculations and plot the results for the whole
                  world.  Currently, there is no mechanism to allow maps
                  to be "merged", but it is relatively simple and may be
                  undertaken if the need arises.

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25 Oct 1995    1. A problem with slewed antennas in HFANT was corrected.
                  The slew angle could not be set to a value between 0 and -30.
                  Only positive values we allowed.  This has been corrected.

               2. A change has been made to the area coverage plotting.
                  It should not be noticed as it was an internal change to
                  make it compatible with the Windows version that is being
                  developed.  Let me know if any problems occur.

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21 Nov 1995    1. A problem with Quadrant (type 8) antenna was discovered.
                  The design frequency could not be changed from 10 MHz.
                  This affected both HFANT and and propagation calculations
                  when the quadrant antenna was used.
                  This has been corrected.
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----------------------------- End of 1995 --------------------------------------
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