-------------------------------------------------------------------------------- All 1995 News for NTIA/ITS HF Propagation Models -------------------------------------------------------------------------------- 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. -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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. -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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. -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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. -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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. -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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. -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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. -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- 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. -------------------------------------------------------------------------------- ----------------------------- End of 1995 -------------------------------------- --------------------------------------------------------------------------------