GWPROP GWPROP
AN HF PROPAGATION PREDICTION PROGRAM AN HF PROPAGATION PREDICTION PROGRAM
Version 3.01
Copyright March 1994

Contents Contents

1. Introduction . . . . . . . . . . . . . . . . . . 4

2. General Description . . . . . . . . . . . . . . 5

3. Installation . . . . . . . . . . . . . . . . . . 8

4. Editing Input Data . . . . . . . . . . . . . . 10

5. Control and Input Menus . . . . . . . . . . . 13
Primary Menu . . . . . . . . . . . . . . . . 13
Time and Solar Activity . . . . . . . . . . 14
Transmitter and Receiver Station Parameters 15
Retrieving Station Parameters from File . . 17
Retrieving an Antenna Pattern from File . . 18
Limits, Conditions and Other Requirements . 19
Frequency Tabulation . . . . . . . . . . . . 21
Archive Circuit Parameters . . . . . . . . . 21
Retrieve Circuit from File . . . . . . . . . 23
Execution Methods . . . . . . . . . . . . . 23
Setting up Routine, General . . . . . . . . 24
Setting up Routine, Graphics . . . . . . . . 26
Ancillary Functions . . . . . . . . . . . . 29
File Errors . . . . . . . . . . . . . . . . 31

6. Output Displays . . . . . . . . . . . . . . . 32
General . . . . . . . . . . . . . . . . . . 32
Key Functions . . . . . . . . . . . . . . . 33
Displays and Plots for Execution Methods . . 33
Mixed Mode . . . . . . . . . . . . . . . . . 35
Sporadic E . . . . . . . . . . . . . . . . . 35
Control Parameters . . . . . . . . . . . . . 35
Global Predictions of MUFs and FOTs . . . . 36

CONTENTS CONTENTS

Predicted MUFs modified for Local Magnetic K-
Indices . . . . . . . . . . . . . . . . 37
Upper and Lower Frequency Limits . . . . . . 37
Service Reliabilities and Probabilities . . 39
System Performance Predictions and Path
Geometry . . . . . . . . . . . . . . . 40
System Performance of Individual Modes . . . 42
Reflection Area Data . . . . . . . . . . . . 42
Performance tables at Specified Frequencies 44
Print or Output to File . . . . . . . . . . 45

7. Graphic Displays . . . . . . . . . . . . . . . 47
Graphic Plots . . . . . . . . . . . . . . . 47
Printer Output . . . . . . . . . . . . . . . 48
Key Functions . . . . . . . . . . . . . . . 49

8. Files . . . . . . . . . . . . . . . . . . . . 50
Global and Seasonal Maps . . . . . . . . . . 50
Circuit and Environment Parameters . . . . . 51
Antenna Files . . . . . . . . . . . . . . . 51
File Input/Output Errors . . . . . . . . . . 52

9. Antenna Program . . . . . . . . . . . . . . . 53
Primary Menu . . . . . . . . . . . . . . . . 53
Antenna Menus . . . . . . . . . . . . . . . 54
Set Frequency Range . . . . . . . . . . . . 56
Set Colours . . . . . . . . . . . . . . . . 56
Common Parameters Menu . . . . . . . . . . . 56
General . . . . . . . . . . . . . . . . . . 58
Resolution . . . . . . . . . . . . . . . . . 58
Antenna Gain and Losses . . . . . . . . . . 58
Environment File . . . . . . . . . . . . . . 59

Appendix A - Antenna File Format . . . . . . . . 60

Appendix B - Archive File Formats . . . . . . . . 62

Appendix C - Environment File Formats . . . . . . 64
Main Program Environment File . . . . . . . 64
Antenna Environment File . . . . . . . . . . 66

CONTENTS CONTENTS

Appendix D - Miscellaneous Information . . . . . 68
Operational Hints . . . . . . . . . . . . . 68
Turbo Pascal . . . . . . . . . . . . . . . . 68

Appendix E - Conversion Tables . . . . . . . . . 70
Decibels with respect to 1 watt . . . . . . 70
Decibels with respect to 1 microvolt . . . . 71

Appendix F - License . . . . . . . . . . . . . . 72

INTRODUCTION INTRODUCTION

1. Introduction 1. Introduction

The program computes predictions of sky-wave
propagation for radio communication systems operating
in the short wave bands, ie 1.6 to 30 MHz. A choice of
outputs is provided from basic Maximum Usable
Frequencies etc to detailed tables of the system
performance along the dominant paths.

The program was based on a report and program by
The Institute for Telecommunication Sciences, Boulder,
Colorado (ESSA Technical Report ERL 110-ITS 78)
"Predicting Long-Term Operational Parameters of High-
Frequency Sky-Wave Telecommunication Systems".

The program has been developed to run on an IBM PC
or clone, XT or better, with 640 K-bytes of memory,
hard disc and preferably a co-processor. Typical
execution times for one of the longer processes were
found to vary from 4 minutes on a 12.5 MHz XT to 1
minute on a 25 MHz 386SX, both using co-processors.
Without a co-processor the 386SX took 12 minutes.

No attempt has been made in this manual to explain
the mechanics of the ionosphere or the solar or
magnetic effects upon it, as there already exists many
suitable publications covering the matter.

GENERAL DESCRIPTION GENERAL DESCRIPTION

2. General Description 2. General Description

The fundamental routines of this program were
based on the maps and algorithms of the ESSA report.
The report also had a strong influence on the format
and content of some of the output displays.

This program has been designed for direct keyboard
entry and analysis on the monitor screen while
providing printed copy as desired. Data input is
achieved by editing existing parameters via menus.
Default parameters are initially set in the program,
but under normal operation most of these would be
overwritten by those retained on disc from a previous
execution.

The program of the above mentioned report had
imposed frequency limits at 2 and 30 MHz. In this
program the range has been allowed to extend from 1.5
and 60 MHz to cover the 160 and 6 metre amateur bands,
the latter often providing communication via Sporadic
E.

In an attempt to simplify operation, tables of
local conditions or requirements have been included
wherever appropriate. To keep numeric fields within
reasonable lengths logarithmic units were use in
preference to absolute, ie decibels with respect 1 Watt
(dBW) and 1 micro-Volt (dBuV). Conversion tables are
provided in the appendices.

Because of the many different types, antenna
routines have not been included in this program.
However, algorithms for four simple theoretical
antennas have been provided and provision made for the
import of antenna patterns from externally produced
ASCII files. An external program to generate files of
three basic types of antenna is also supplied with the
program.

GENERAL DESCRIPTION GENERAL DESCRIPTION

Provision has been made for archiving frequently
used circuit parameters onto disc and for their
retrieval.

A choice of ten forms of tabulated output are
available for display and printing. These are
supported by seven graphical outputs.

1) Global predictions of Maximum Usable Frequencies
(MUFs) and Frequence Optimal de Travil (FOTs) at
10 radial distances and 12 bearings from a
selected central position. The associated graphs
indicate contours of MUFs or FOTs in polar form.

2) Predictions of MUFs and FOTs between a selected
receiver position and co-ordinate points based on
a 30 degree spacing about the globe displayed in a
linear rectangular form. The associated graphs
are similar to that of method 1 but displayed as a
Plate Carree projection of the globe (linear).

3) Predictions of MUFs or FOTs for up to 24 hours
between a selected receiver position and co-
ordinate points based on a 30 degree spacing about
the globe. Graphs as for 2 above.

4) Up to 24 hours of predicted MUFs between two
stations against Local Magnetic K indices. Plots
are provided of the MUF and that for three values
of K against time.

5) Up to 24 hour predictions of MUFs, FOTs and
Highest Possible Frequencies (HPFs) with
propagation modes and launch angles. Plots are
provided of the three frequencies against time.

6) Same as 5 but including Lowest Usable and Highest
Reliable Frequencies of reception (LUFs and HRFs).
A plot of the area enclosed by the LUFs and HRFs
are included with the graphs of method 5.

GENERAL DESCRIPTION GENERAL DESCRIPTION

7) Up to 24 hours of MUFs and System Reliabilities or
Probabilities for up to 30 selected frequencies.
The associated graph shows contours of 5 levels on
a frequency against time chart.

8) Predictions of performance for up to 30 selected
frequencies. Two separate charts show various
performance results against frequency.

9) An extended version of 8 with additional
performance data. Graphs as for method 8,

10) General predictions of performance of the dominant
paths of propagation for up to 30 selected
frequencies. Graphs as for method 8.

INSTALLATION INSTALLATION

3. Installation 3. Installation

Thirty two files are supplied with the system.
The files are:

The System Files
The main prediction program - GWPROP.EXE
The antenna program - ANTENNAS.EXE
The world maps - WORLD.BIN
CALJAN.BIN - CALFEB.BIN - CALMAR.BIN
CALAPR.BIN - CALMAY.BIN - CALJUN.BIN
CALJUL.BIN - CALAUG.BIN - CALSEP.BIN
CALOCT.BIN - CALNOV.BIN - CALDEC.BIN

Video Drivers
ATT.BGI - CGA.BGI - EGAVGA.BGI
HERC.BGI - IBM8514.BGI
PC3270.BGI - VESA16.BGI

Starter Files
Environment files - ENVIROMT.SAV
- ANTENVIR.SAV
Sample Circuit files - PHUS-BUK.CIR
- DEFAULT.CIR
Sample Gazetteer file - GAZETEER.DAT
Sample Antenna file - VERT24FT.ANT

Miscellaneous Files
The instruction manual - MANUAL.DOC
File examples - EXAMPLE.DOC
The readme file - READ.ME
Installation file - INSTALL.BAT

To install the program it is only necessary to
extract the files into the chosen directory from which
the system is to be operated. This can be achieved by

INSTALLATION INSTALLATION

creating a directory and then copying the files into it.
The batch program INSTALL.BAT is provided to carry out
this operation. To operate insert the source disc into
a drive and at the prompt type:

s:\INSTALL s d dir [R]

where s = source disc drive
d = destination disc drive
dir = target directory to be created
R = option to run program

The following example would copy the files from
disc drive A, store them in directory PROP (which
would be created if not already existing) on drive
C and run the program.

A:\INSTALL A C PROP R

The batch program will load all the files in a
single directory. If desired, files may be re-
organised into object oriented directories after
loading.

If it is decided to keep the supplied environment
file in the operating directory then it will supply the
initial defaults and will be overwritten on completion
of the first program operation. The same will apply to
the antenna environment file and program.

EDITING INPUT DATA EDITING INPUT DATA

4. Editing Input Data 4. Editing Input Data

Selections from the Primary and Execution menus
are achieved by typing a single character. Secondary
level menus use the Arrow, Home and End keys for
selecting and editing parameters.

Down Arrow Advance to next field.
Up Arrow Go back to previous field.
Right Arrow Advance cursor one character within a
string field, or to the beginning of the
next field if at the end of a field.
Change option in option field.
Left Arrow Retract cursor one character within a
string field, or to the beginning of the
last field if at the start of a field.
Reverse change of option in option
field.
Home Go to first field.
End Go to last field.
Delete Delete character at cursor in a string
field.
Backspace Delete character to left of cursor in a
string field.
Return Store all changes and return to previous
level.
ESC Cancel changes and return to previous
level. 'X' also causes exit in some
displays and menus where it does not
conflict with its use in strings etc.

Question Mark This character is used in the
Transmitter/Receiver Menu to initiate a
search for station entries in the
gazetteer file, but is otherwise
ignored.

Fields that can be edited are highlighted.
Modification of certain fields is only possible if a
preceding field has been set to a certain condition

EDITING INPUT DATA EDITING INPUT DATA

such as setting an option to 'User' or 'File'. In such
a condition the field will be highlighted otherwise the
highlight will be turned off.

There are three types of field, Alphanumeric,
Options and Numeric. Alphanumeric fields are for
specifying names of stations and files. Any legal DOS
character is allowed. The maximum number of characters
allowed is indicated by the size of the highlighted
box. Backspace, Delete and Left and Right Arrows are
effective during field editing. The final string will
be made left justified.

ΪΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΏ
³ Transmitter Station[Philadelphia, Pn] ³
³ ³
³ Co-ordinates[ 75.00 West] [40.00 North] ³
³ ³
³ Power [40.0](dBW) ³
³ ³
³ Local Noise Level[Urban] -136.5 dBW/Hz ³
³ ³
³ Antenna [Omnidirectional] ³
³ ³
³ Additional Gain[ 0.0] (dB) ³
ΐΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΩ
Typical Menu Typical Menu
Highlighted fields are shown in square brackets

Option fields are cycled by using the Left or
Right Arrows, the right arrow reverses the order of
selection.

Values in Numeric fields are edited the same as
Alphanumeric. When an attempt is made to move to
another field it is checked for both valid format and
limits. Failure is indicated by an error message and
the cursor will be positioned at the first illegal
character, or at the left of the box if the value is
outside its limits. The final value will be made right
justified.

EDITING INPUT DATA EDITING INPUT DATA

In the case of an error being detected the numeric
field may be left only by correcting it or using the
ESC key to cancel all changes made and return to the
main menu.

There is a fourth type of field, used for
specifying printer escape sequences. It is really an
extension of the alphanumeric field but accepts
hexadecimal strings. On leaving the field each pair of
characters is checked for validity.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

5. Control and Input Menus 5. Control and Input Menus

Input data is controlled by editing, so that it is
only necessary to change those parameters needed to be
changed. For instance, the smoothed sun spot number
would remain stable over short periods and some of the
local parameters could be common to several circuits.

Initial defaults are written in the program. At
the start of the program the majority of these will be
overwritten by the contents of the file 'ENVIROMT.SAV',
if it exists. Exceptions include the time and date
that are set from the computer clock.

Primary Menu Primary Menu

Input data is organized into specific groups each
of which can be accessed from the primary menu by
typing one letter.

ΪΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΏ
³ Time and Solar Activity : D ³
³ Transmitter Station Parameters : T ³
³ Receiver Station Parameters : R ³
³ Limits and Other Requirements : L ³
³ Range of Frequency : F ³
³ Retrieve Circuit Parameters : C ³
³ Archive Circuit Parameters : A ³
³ Setup Environment (General/Graphics) :S/G ³
³ Display the Execution Menu : E ³
³ Exit without saving Environment :ESC ³
³ Save Environment and Exit Program : X ³
ΐΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΩ
Primary Menu Primary Menu

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

Time and Solar Activity - D Time and Solar Activity - D

Date of Forecast
Day of the Month Range 1 to 31
Month of the Year Range 1 to 12
Year Range 1 to 9999
Default = Current date.

The year is cosmetic and only used for output
displays.

Hour of Start
Range 1 to 24.
Default = Current UTC hour + 1

Hour of Finish
Range 1 to 24.
Default = Current UTC hour + 1

If the end hour is set earlier than the start the
time will be sequenced via midnight. Note the hour is
signified by the time at the end of the hour, eg hour 1
is the hour from 0000 to 0100 hours UTC.

Incremental Step
Range 1 to 4.
Default = 1

Calculation will begin with the start hour, and
end with the specified hour of finish irrespective of
where the steps would place it. The time range and
stepping may be overridden by the F8 Function Key. See
below.

Smoothed Sun Spot Number
Range 0 to 300
Default = 100

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

10 Centimetre Flux
Range 63.7 to 362.5
Default = 145.4

The 10 centimetre flux is an alternative entry to
the Smoothed Sun Spot Number. Modification of one
automatically changes the other.

Transmitter and Receiver Station Parameters - T Transmitter and Receiver Station Parameters - T

Name of Station
Maximum length 16 alphanumeric characters.
Default = Blank field

Latitude Co-ordinates
Range 90.0 degrees South to 90.0 degrees North
Default = 0.0 degrees North

Longitude Co-ordinates
Range 180.0 degrees East to 180.0 degrees West
Defaults Tx = 0.0 degrees West
Rx = 90.0 degrees West

If the latitude of a station is set to a Pole, ie
90.0, the longitude will be changed to that of the
other station.

Transmitter Power
Power in decibels with respect 1 Watt (dBW)
Range -30.0 to +90.0 dBW ( 1 mW - 1000 MW )
Default = 40.0 dBW ( 10 kilowatt )

Transmitter power is that measured at the
transmitter antenna terminals and should take account
of feeder losses etc. This is obviously not required
as a receiving station parameter.

Local Man-made Noise Spectrum
This is a variable generally decreasing with
frequency and is specified by the Spectral Density

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

at 3MHz, and is given in decibels with respect to
1 Watt per Hertz bandwidth, from which the
spectrum is calculated. Six options are provided
as specified below.

Options
Urban plus -128.5 dBW/Hz at 3MHz
Urban -136.5 dBW/Hz at 3Mhz
Suburban -148.6 dBW/Hz at 3MHz
Rural -165.6 dBW/Hz at 3MHz
Quiet -204.0 dBW/Hz at 3MHz
User As specified by user
Default = Suburban

User Specification
User range -204 to 0 dBW for 1Hz bandwidth
User default = as for Suburban

Urban, Suburban and Rural are based on documented
measurements, while Urban plus and Quiet has been added
to cover extreme cases. The User option allows the
user to specify his own figure for the noise density at
3 MHz from which a spectrum will be calculated. In
each of the above cases the noise density at 3 MHz will
be displayed in the header. This is not required as a
transmitting parameter.

Antenna Pattern.

Four theoretical antenna patterns are available
within the program or patterns can be imported. The
internal patterns assume perfectly conducting earth and
have been ascribed the appropriate peak gains. All are
assumed to be insensitive to bearing or frequency.

Options
Omnidirectional Constant gain at all angles.
Gain = 3.01 dB
Sine Law Sine of angle of elevation.
Peak gain = 7.78 dB at 90
degs.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

Cosine Law Cosine of angle of elevation.
Peak gain = 4.77 dB at 0 degs.
Sine-cosine Law Sine of 2 x angle of
elevation.
Peak gain = 5.68 dB at 45
degs.
File Pattern to be read from file.
Default = Omnidirectional

File Name.
Maximum length 8 alphanumeric characters
Default = Blank field

Evoked when the option 'File' is selected and will
transfer control to the antenna file selection routine.
See below.

Additional Gain in decibels (dB)
Range -30.0 dB to +50.0 dB
Default = 0.0 dB

This feature allows the user to modify the gain of
a theoretical or imported antenna to match another
antenna with a similar pattern but differing gain.
Ideally this parameter should not be used for inserting
additional antenna and feeder losses.^1

Retrieving Station Parameters from File Retrieving Station Parameters from File

Station parameters for certain stations may be
retrieved from the gazetteer file while editing the
station field of the transmitter or receiver menu.
____________________

^1 Assuming received noise is omnidirectional,
antenna and feeder losses have equal effect upon signal
and noise at the receiver whereas gain only effects the
signal. Thus describing losses as negative gain would
produce an error in the calculations. See Ancillary
Functions page 29.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

To check that the required station is in the file,
type some of the leading letters followed by a question
mark. The file will be searched sequentially until a
match is found and the parameters of the match will be
displayed. Re-typing the question mark will find the
next match, and so on. After the last matching item is
found the file will be re-cycled to find the first
match again.

If a match cannot be found after one cycle of the
file, the sample will be shortened by one character and
retried. Note that by placing the curser at first
character position every entry in the gazetteer file
can be displayed.

The parameters will be retained on leaving the
field or exiting the transmitter or receiver menu.

Retrieving an Antenna Pattern from File Retrieving an Antenna Pattern from File

If the antenna option 'File' is selected from the
Transmitter or Receiver menus the antenna directory
will be searched and the names of all the files with
the extension '.ANT' displayed with their dates of
creation in 'ddmmyy' format. A maximum of thirty file
names can be displayed at a time. A space or a page
key will produce the next 30 file names, or the first
30 if viewing the last. Typing an 'X' or 'ESC' will
cause return to the main menu without further action.

The arrow keys or the number the left of its name
may be used to select a file. A return will result in
the display of the description of the antenna found in
the comment section of the selected file. A second
return will cause the file name to be recorded, but the
tables will not be loaded into the memory until program
execution. A space will reproduce the file list, while
'X' or ESC will exit to the main menu without further
action.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

Limits, Conditions and Other Requirements - L Limits, Conditions and Other Requirements - L

Required Signal to Noise Ratio

Service Options
DSB AM Double sideband AM 75/51/41 dB/Hz
SSB AM Single sideband AM 72/48/38 dB/Hz
Sync FSK Synchronised FSK 65/59/50 dB/Hz
Unsync FSK Unsynchronised FSK 68/62/55 dB/Hz
CW W/T CW morse system 45/39/30 dB/Hz
User User defined
Default = DSB AM

The figures shown indicate the values of Signal to
Noise ratios selected for the associated selection of
High/Medium/Low grades respectively as given below.
The figures for CW were based on a 30Hz bandwidth and a
15dB signal to noise ratio for low grade operation.^2
The figures for FSK were based on a bandwidth of 110Hz.

Grade Options
High Good commercial quality AM or
1 in 10,000 error rate FSK.
Medium 90 % Intelligibility AM-RT or
1 in 1,000 error rate FSK.
Low Minimum acceptable AM-RT or
1 in 100 error rate FSK.
Default = High

User Specification
User range 0.0 to 120.0 dB/Hz
User default = As for DSB AM

____________________

^2 Unfortunately substantiated data regarding
intelligibility levels for CW signal to noise ratios
were not known to the author but it was felt that an
estimated figure should be included for the sake of
completeness.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

The Required Signal to Noise Ratio is that which
must be satisfied when determining Reliability. It is
expressed as the ratio of the signal to the noise
density at the signal frequency.^3 A table of
accepted values for different operating modes can be
referenced by selection of one of the above options
followed by a Grade of service selection of High,
Medium or Low. Alternately the User option allows the
user to specify the value directly.

Required Reliability
Range 1 to 99 %
Default 90 %

The Required Reliability is that which must be
satisfied when determining LUF and HRF or System
Probability.

Minimum Launch Angle
Range 0.0 to 90.0 degrees
Default 0.0 degrees

The Minimum Launch Angle allows the user to
restrict calculations to elevations above the level
where nearby structures may have indeterminate effects.
3 degrees is a popular choice.

Multi-path Signal Power Ratio
Range 0.0 to 90.0 dB
Default = 10.0 dB

The minimum acceptable power ratio in dB between
the received strength of the signal on the main path
and that from an interfering path. Acceptable is
defined as a level at which reception remains
intelligible
____________________

^3 This may also be thought of as the product of
the required signal to noise ratio at the receiver
detector and the bandwidth of the preceding filters.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

Multi-path Propagation Delay Time
Range 0.0 to 100.0 milliseconds
Default = 0.85 millisecond

The maximum acceptable difference in propagation
time in milliseconds between the signal on the main
path and that from the interfering path mentioned
above.

Frequency Tabulation - F Frequency Tabulation - F

Options
Standard Logarithmic spread from 2.0 to 30 MHz.
Amateur Amateur Bands from 1.82 to 52 MHz.
Linear From 1.5 to 30 with 2.5 MHz spacing.
Wide Lin From 1.5 to 60 with 2.5 MHz spacing.
Full Lin From 1.5 to 30 with 1.0 MHz spacing.
Broadcast Commercial broadcast bands.
User User defined. Up to 30 frequencies can
be defined.
Default = Standard

User Specified
Range 0.0 to 60.0 MHz
Maximum number of frequencies = 30
Default frequencies = as for Standard

The list may be terminated with a value of 0.0.

Archive Circuit Parameters - A Archive Circuit Parameters - A

Archive Option Field

Circuit Circuit parameters to Circuit file
Transmitter Transmitter parameters to Gazetteer
Receiver Receiver parameters to Gazetteer

The transmitter and receiver options enter the co-
ordinates, power, local noise and antenna details of

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

the transmitter or receiver respectively into the
gazetteer file 'GAZETEER.DAT' under the specified name.

The circuit option creates a file and stores both
the transmitter and receiver parameters plus the
service type, grade and required signal to noise ratio
in it.

The following fields are only appropriate to the
circuit option.

File Name
Maximum length 8 alphanumeric characters

The name may consist of any characters permitted
by DOS. The extension '.CIR' will be appended by the
program.

Title
Maximum length 12 alphanumeric characters

This is an optional field for displaying at the
top of the screen as an identifying title. If an
asterisk is placed in the first position the field will
be replaced by the file name. This title is never
printed.

Additional Description or comments
Maximum length 2 lines x 50 alphanumeric
characters

Up to 100 characters may be entered as an
additional description or comments to that
automatically provided by the program.

Annotation Option
Included
Excluded - Default

Included will cause 3 lines of basic annotation to
be inserted in the file.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

A return will cause the file to be created whilst
an ESC will return to the main menu without further
action.

Retrieve Circuit from File - C Retrieve Circuit from File - C

The circuit directory will be searched and the
names of files with the extension '.CIR' will be
displayed with their creation dates. Selection is
exactly the same as for the antenna files, except that
the contents of the circuit file will be loaded before
exiting the selection routine.

Execution Methods - 1 to 10, Menu - E Execution Methods - 1 to 10, Menu - E

Typing 'E' displays the execution menu. Execution
is initiated by typing the figures '1' to '9' for the
display methods 1 to 9 or '0' for method 10. Execution
can also be initiated without necessarily displaying
the menu, which is only an aid.

ΪΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΏ
³ Displays Type ³
³ Forecasts of MUFs at Radial Distances : 1 ³
³ Forecasts of MUFs at Co-ordinates : 2 ³
³ MUFs at Co-ordinates against Time : 3 ³
³ MUFs against Magnetic K Index and Time : 4 ³
³ MUFs, FOTs and HPFs against Time : 5 ³
³ MUFs, FOTs, LUFs and HRFs against Time : 6 ³
³ Forecasts of Reliability against Time : 7 ³
³ Performance against Frequency : 8 ³
³ Extended Performance Prediction Data : 9 ³
³ Performance of Individual Modes : 0 ³
³ Return to Main Menu : Return or Space ³
³ Enter required display : ³
ΐΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΩ
Execution Menu Execution Menu

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

Details of the output display methods are given in
the next section.

Setting up Routine, General - S Setting up Routine, General - S

Directories Paths
The paths must be described in full DOS format, eg
C:\DIR1\DIR2 etc. An empty field is not allowed. An
asterisk can be used to indicate the current directory.
On exiting the field the asterisk will automatically be
replaced by the current directory.

Path to each Directory
Antennas Path to directory holding Antenna files
ie those ending '.ANT'.
Default = Current directory
Circuits Path to directory to hold circuit files
ie those ending '.CIR' and the Gazetteer
file 'GAZETEER.DAT'.
Default = Current directory
Maps Path to directory holding Global and
Seasonal data files, eg 'WORLD.BIN',
'CALJAN.BIN' and 'CALFEB.BIN' etc.
Default = Current directory
BGI files Path to directory holding graphic
display handlers.
Default = Current directory
Output Path to directory to receive output
files
Default = Current directory

Output Device
Printer port or output file.

Options
PRN Standard DOS Driver
LPT1, LPT2, LPT3 Optional printer ports
COM1, COM2 Serial output ports
File Output to File
Default = PRN

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

If the option 'File' is chosen a field for the
file name is displayed to the right of the option.
File names should be entered without the dot extension.
The extension '.OUT' will be added by the program.
Data is entered into the file in printer page format as
given below so that it can be copied direct to a
printer.

Default File = PROPOUTP.OUT

Printer Page Size
The following parameters control the format of
printed output preventing table blocks from bridging
pages. The number of columns will determine the number
of tabulated columns to be printed. This will be the
maximum possible and always including those displayed
on screen.

Lines Height of Printer paper in lines
Range 36 to 200 lines
Default = 64 lines

Columns Width of Printer paper in columns
Range 80 to 255 columns
Default = 80 columns

Local Time Offset
Hours ahead of Universal Time (UT)
Range -13 to +13 hours
Default = 0 hours

Used to set universal time from computer clock.
Set to zero if computer clock is set to UTC. Note this
parameter is only used to set the default times at
program initiation and only has effect on future
operations of the program.

Colours
Pressing the left or right arrow while the cursor
is in the colour field will activate the colour menu.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

The program interprets the graphic adaptor for
colour or monochrome at the start of the program. If
it fails to find the adaptor the operator is requested
to enter 'C' for colour or 'M' for monochrome.

The selector consists of a coloured text with
background for each style used with a letter pair (eg
A/B) to indicate the key to change the colour. The
first is associated with the text and the second the
background. Repeated typing of a letter will cause the
associated sample to cycle the colours available or in
the case of a monochrome system the three basic styles,
normal, inverse and highlighted. Use of the shift key
will reverse the cycle. Typing 'ESC' or Return will
cause exit to the main menu.

On the right of the menu are listed the graphics
colours. The first pair are the grid and background
colours followed by five pairs for lines and polygons.
Each polygon will be bordered by its associated line
colour. The order of these colours is as seen in the
legends at the bottom of each graph.

The default colours are set to a suitable
combination of black, grey and white for monochrome
displays.

Setting up Routine, Graphics - G Setting up Routine, Graphics - G

This is an extension of the setting up routine for
graphic output but mainly the printer parameters
required for hard-copying.

Screen Aspect Ratio Modifier
The aspect ratio, ie the ratio of horizontal
density (dpi) to vertical density, set by the handler
does not always match the video screen. This parameter
provides a correction facility. Typical values
required are 1.0 for VGA and 1.2 for Hercules handlers.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

Range 0.5 to 2.0
Default = 1.00

Printer Type
Specifies common types using standard graphic
sequences.

Options
Laserjet - 75 x 75 dots per inch
Epson 9 pin A - 60 x 60 dots per inch (Single)
Epson 9 pin B - 80 x 60 dots per inch (CRT I)
Epson 9 pin C - 90 x 60 dots per inch (CRT II)
IBM 9 pin A - 60 x 72 dots per inch (Single)
IBM 9 pin B - 80 x 72 dots per inch (CRT I)
IBM 9 pin C - 90 x 72 dots per inch (CRT II)
User Specified

Default = Epson 9 pin B

The plotted output is based on 8 inch (80 column)
paper, thus the optimum choice for matrix printers
would be 'B' 80 dpi for 640 dot wide VGA screens and
'C' 90 dpi for 720 dot wide Hercules systems. If your
printer does not have these options then the single
density option 'A' of 60 dpi is preferred to the higher
double density of 120 dpi. The higher density would
produce a plot 30% narrower without improving the
resolution. However, the aspect ratio for circles
would be maintained.

Character Suppression
Certain characters can suffer special treatment by
the system that can corrupt graphic printing. This
field specifies which ones are to be modified. The
modification is normally achieved by changing one
writing bit to non-writing and only effects the graphic
strings.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

Options
None
EOF only (value 26 - may be suppressed)
CR only (value 13 - system may add LF)
LF only (value 10 - system may add CR)
Combinations of above

Default = EOF only

Byte Format
Byte format refers to the way the data is sent, ie
as a single row or in columns.

Options
8 bit row
8 bit column
24 bit column^4

Default = 8 bit column

Print Density
These two numbers are determined by the printer
and the transmission mode selected below and should be
entered accordingly. As well as the size of the
printed plot these figures also determine the aspect
ratio effecting the elipticalness of the circles drawn.

Range 1 to 200

Horizontal default = 80
Vertical default = 60

Graphic Control Sequences
These are strings of hexadecimal pairs
representing the character sequences required to set up
the printer for graphics, the sequence preceding the
____________________

^4 Although included the vertical resolution would
probably be too high to be of useful purpose.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

data and the sequence to restore the printer to normal.
The positions of data byte counts are represented by
the pairs '#0' for the low byte, and '#1' for the high
byte if required^5.

Defaults
As for Epson 9 pin B
Set up = 1B3318
Preceding Data = 1B2A04#0#1
Restore = 1B32

Fill Patterns and Line Styles
No facilities have been provided in the program
for changing the fill patterns or line styles, however,
these can be modified by editing their index values in
the environment file 'ENVIROMT.SAV'^6.

Ancillary Functions Ancillary Functions

Eight other functions which perform changes
directly are available while the primary or execution
menus are displayed. These are displayed on the
message line.

F1 Help displays a menu of function key operations
below.

____________________

^5 The character '#' refers to that of value 35
(hex 23) ie shift '3' on the keyboard.

^6 See Appendix C Page 64 for the Environment File
format and Appendix D Page 69 for fill pattern and line
style indices.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

F2 This key exchanges transmitter and receiver
parameters. This facility allows the user to
compare the performance of the reverse path in two
way systems where the probability of communication
would be determined by the path direction
producing the weaker performance.^7

F3 This key toggles whether the prediction will be on
the long or short great circle path of
propagation.

Status Shown in header
Default Short Path

F4 This key toggles whether the prediction will take
account of Sporadic E.

Status Shown in header
Default Sporadic E included

F5 This key toggles choice of displaying probability
or reliability in the output of methods 7 to 10.
Probabilities take slightly longer to calculate.

Status Shown in Message line as Reli or Prob
Default Reliability

____________________

^7 Sky wave propagation is independent of
direction, however, the transmitter power, antenna
losses and local noise levels at the receiver will
produce differences in the overall performance. Thus
swapping the parameters would have no affect on the
figures displayed by methods 1 to 5 but could affect
the displays of reliability etc. Note that the program
assumes that at either end of the circuit the same
antenna will be used for both transmission and
reception.

CONTROL AND INPUT MENUS CONTROL AND INPUT MENUS

F6 This key toggles choice of displaying MUFs or FOTs
with display methods 1 to 3 and 7. This function
is also operative while displaying methods 1 to 3.

Status Shown in Message line
Default MUFs

F7 This key toggles choice of output to screen or
direct to the printer.

Status Shown in Message line as Scrn or Prnt
Default Screen

F8 This key toggles override of the time settings of
menu 'D' above.

Status Shown in Message line as Norm or 24hr
Norm As set in menu 'D'.
24hr Time increments are set to one hour for
all methods of display.
Start and end hours are set to 1 and 24
for methods 1 to 7 and for the printing
of methods 8 to 10 only.
Default Norm

File Errors File Errors

Execution always ceases when a file error or
warning occurs. The operation of any key will allow
operation to proceed. In the case of an error the rest
of the file is ignored, but after a warning message
reading will continue from where the problem
occurred.^8

____________________

^8 See also Files Input/Output Errors page 52.

OUTPUT DISPLAYS OUTPUT DISPLAYS

6. Output Displays 6. Output Displays

General General

Most of the output displays are of a single screen
with the control parameters displayed at the top.
Where there is too much information to display on a
single screen the arrow keys can be used to cycle the
results left or right and up and down.

Display methods 1 to 7 produce up to 24 hours of
tables in one operation while 8 to 10 produce one hour
at time and can only be inspected sequentially.

Methods 1 and 2 have separate displays for each
hour which can be cycled with the page keys. Function
key F6 will toggle the display of MUFs and FOTs.

Similarly method 10 produces a whole hour of
results in one operation but each hour consists of a
screen for each frequency specified and an header for
the hour. The screens may be cycled by the Up and Down
arrow keys.

Changing the hour with display methods 8 to 10 may
be achieved with the Page keys. Page Down increments
the hour while Page Up decrements it. The Page keys
will cause the program to proceed and start calculating
the performances for the next or preceding hour
respectively. The results of the previous calculation
will be lost from memory. An Escape will abort the
hour cycle and revert to the execution menu.

OUTPUT DISPLAYS OUTPUT DISPLAYS

Key Functions Key Functions

Down arrow Scroll table upwards bringing
undisplayed rows onto the bottom of the
screen while upper rows are removed.
Also steps to next frequency during the
display of method 10.
Up arrow Reverse effect of Down arrow. Also
steps back to previous frequency while
displaying method 10.
Right arrow Scroll table left bringing undisplayed
columns onto right of screen while left-
hand columns are removed.
Left arrow Reverse effect of Right arrow.
Page Down Displays next hour on methods 1 and 2.
Initiates calculation of the next hour
with displays 8 to 10.
Page Up Displays previous hour in methods 1 and
2. Initiates calculation of the
previous hour with displays 8 to 10.
Letter G Replaces display with associated Graphic
display.^9
Letter P Sends data displayed plus that off-
screen to the printer.
Figs 0 to 9 Changes display method where permitted.
See diagram below.
F6 Toggles MUFs or FOTs with display
methods 1 to 3.
Return,X,ESC Return to execution menu.

Displays and Plots for Execution Methods Displays and Plots for Execution Methods

Although the display method is decided at the
initial time of execution, access to a limited number
of other methods of display are possible at display
time. The displays available after execution are
____________________

^9 See Graphic Displays section Page 47

OUTPUT DISPLAYS OUTPUT DISPLAYS

indicated in the diagram below with the plots that are
also accessible^10.

ΪΔΔΔΔΔ�ΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΏ
³ Ί Execution Method ³
³ ΗΔΔΔΒΔΔΔΒΔΔΔΒΔΔΔΒΔΔΔΒΔΔΔΒΔΔΔΒΔΔΔΒΔΔΔΒΔΔΔ΄
³ Ί 1 ³ 2 ³ 3 ³ 4 ³ 5 ³ 6 ³ 7 ³ 8 ³ 9 ³ 10³
ΖΝΡΝΝΝΞΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝµ
³ ³ 1 Ί x ³ ³ ³ ³ ³ ³ ³ ³ ³ ³
³D³ 2 Ί ³ x ³ x ³ ³ ³ ³ ³ ³ ³ ³
³i³ 3 Ί ³ x ³ x ³ ³ ³ ³ ³ ³ ³ ³
³s³ 4 Ί ³ ³ ³ x ³ x ³ x ³ x ³ ³ ³ ³
³p³ 5 Ί ³ ³ ³ x ³ x ³ x ³ x ³ ³ ³ ³
³l³ 6 Ί ³ ³ ³ ³ ³ x ³ ³ ³ ³ ³
³a³ 7 Ί ³ ³ ³ ³ ³ ³ x ³ ³ ³ ³
³y³ 8 Ί ³ ³ ³ ³ ³ ³ ³ x ³ x ³ x ³
³s³ 9 Ί ³ ³ ³ ³ ³ ³ ³ x ³ x ³ x ³
³ ³10 Ί ³ ³ ³ ³ ³ ³ ³ ³ ³ x ³
ΖΝΨΝΝΝΞΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝΨΝΝΝµ
³ ³ 1 Ί x ³ ³ ³ ³ ³ ³ ³ ³ ³ ³
³P³ 2 Ί ³ x ³ x ³ ³ ³ ³ ³ ³ ³ ³
³l³ 3 Ί ³ ³ ³ x ³ x ³ x ³ x ³ ³ ³ ³
³o³ 4 Ί ³ ³ ³ x ³ x ³ x*³ x ³ ³ ³ ³
³t³ 5 Ί ³ ³ ³ ³ ³ ³ x ³ ³ ³ ³
³s³ 6 Ί ³ ³ ³ ³ ³ ³ ³ x ³ x ³ x ³
³ ³ 7 Ί ³ ³ ³ ³ ³ ³ ³ x ³ x ³ x ³
ΓΔΑΔΔΔΠΔΔΔΑΔΔΔΑΔΔΔΑΔΔΔΑΔΔΔΑΔΔΔΑΔΔΔΑΔΔΔΑΔΔΔΑΔΔΔ΄
³ * Plot 4 with contour of reliable reception ³
ΐΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΩ
Display and Plots Display and Plots
available with each Execution Method available with each Execution Method

____________________

^10 See Graphics Displays Page 47

OUTPUT DISPLAYS OUTPUT DISPLAYS

Mixed Mode Mixed Mode

Mixed mode propagation is not considered in the
calculation of FOT, MUF or HPF where such occurrences
are rare. However, it is taken into account when
predicting LUF, HRF and performance. In such cases
mixed mode will always consist of one E layer, normal
or sporadic, with one or more F layer reflections.

Sporadic E Sporadic E

If sporadic E is specified then it will be
included in all the calculations of the useful
frequencies and performance etc otherwise only the F
and normal E layers will be considered. However, the
values of ESFOT, ESMUF and ESHPF will be displayed by
methods 8 to 10 irrespectively.

It should be remembered that ESFOT, ESMUF and
ESHPF are derived from medians and deciles of measured
observations and only represent probabilities.

Control Parameters Control Parameters

The input parameters are displayed on the top 8
lines of the screen during editing. During execution
and output this is limited to information relevant to
the selected method of display.

On program entry the parameters are set to the
defaults unless the file ENVIROMT.SAV exists which will
overwrite them. The exceptions are the time and date
that are set from the computer clock.

1) Circuit Title. Displays the title given to the
last circuit to be archived or retrieved, or its
file name. Only displayed during edit mode and
not printed.
2) Date for prediction.

OUTPUT DISPLAYS OUTPUT DISPLAYS

Smoothed Sun Spot Number and 10cm Flux.
3) Transmitter Name and Geographical Coordinates.
Receiver bearing and distance in miles calculated
from the station coordinates.
4) Transmitter Power displayed in decibels relative
to 1 watt.
Transmitter Antenna. The antenna field indicates
either the chosen pattern or the name of the file
supplying the pattern.
Addition Antenna Gain in decibels.
5) Receiver Name and Geographical Coordinates.
Transmitter bearing and distance in kilometres
calculated from the station coordinates.
6) Local Noise Density at the receiver in decibels
relative to 1 watt/Hz at 3 MHz.
Receiver Antenna. The antenna field indicates
either the chosen pattern or the name of the file
supplying the pattern.
Addition Antenna Gain in decibels.
7) Required Reliability as a percentage.
Required Signal/Noise Ratio in dB (Noise in 1Hz
bandwidth).
Acceptable limits of Multi-path Propagation,
Power Ratio in decibels and
Delay in milli-seconds.
8) Specified Minimum Launch Angle in degrees.
Long or Short Great Circle Path.
Sporadic E Included or Excluded.

Output Displays 1 to 3 Output Displays 1 to 3
Global Predictions of MUFs and FOTs Global Predictions of MUFs and FOTs

These displays predicts the MUFs and FOTs in MHz
between a specified location, the receiver, and other
stations sited around the globe. Display 1 uses radial
positioning based on 10 distances and 12 azimuth
bearings from the receiver position, while 2 and 3 uses
positioning based on co-ordinates at 30 degree spacing.

OUTPUT DISPLAYS OUTPUT DISPLAYS

With method 1 the distances are given as 1000s of
kilometres and the bearings in degrees from true north.

Distance = 0.5, 1.0, 1.5, 2.0, 2.5,
3.0, 3.5, 4.0, 4.5, 5.0.

Bearings = 0.0 to 330 in 30 degree steps

With method 2 and 3 all positions are given as
degrees North or South and East or West.

Displays 1 and 2 display one hour per screen only
whereas 3 shows all on one screen.

Output Display 4 Output Display 4
Predicted MUFs modified for Local Magnetic K-Indices Predicted MUFs modified for Local Magnetic K-Indices

This display provides up to 24 hours of Predicted
MUFs modified for Local Magnetic k-index.

Output Displays 5 and 6 Output Displays 5 and 6
Upper and Lower Frequency Limits Upper and Lower Frequency Limits

These displays provide up to 24 hours calculation
of Frequency Limits. All, with the exception of the
Lowest Usable and Highest Reliable Frequencies of
reception (LUF and HRF), are determined by ionosphere
conditions only and can be calculated without
consideration of communication equipment. However, the
calculation of the LUF and HRF requires both knowledge
of the transmitter and receiver station equipment and
the path loses between them. Because of this and the
greater calculation time needed a choice is provided,
display 5 without LUFs or HRFs and 6 with.

OUTPUT DISPLAYS OUTPUT DISPLAYS

Definitions

FOT 'Frequence Optimal de Travil'.^11 The highest
frequency having at least a 90% probability of
propagation by a sky wave.

FOT, MUF and HPF ignores path losses and does not
indicate probable reception.

MUF 'Maximum Usable Frequency'.^12 The highest
frequency having at least 50% probability of
propagation by a sky wave.

For reflections from the normal E layer the FOTs
and HPFs are set to the same frequencies as the
MUFs.

HPF 'Highest Possible Frequency'. Highest Frequency
having at least a 10% probability of propagation
by a sky wave.^13

____________________

^11 The FOT is often considered as a rule-of-thumb
for optimum reception. It is sometimes known as the
'Optimum Working Frequency' (OWF).

^12 Technically the MUF is the highest frequency of
propagation by a sky wave. However, because of the
uncertainty attached to its value it is defined here as
the frequency of equal probability (50%).

^13 The HPF is generally used as a check on the
probability of interference from another transmitter
operating on the same frequency.

OUTPUT DISPLAYS OUTPUT DISPLAYS

LUF 'Lowest Usable Frequency of reception'. Lowest
frequency that meets a specified reliability of
communication (usually 90%). Display 6 only. An
hyphen '-' indicates that communication with the
specified reliability is improbable. A value
below 1.5MHz is displayed as '<1.5'.^14

HRF 'Highest Reliable Frequency of reception'. Highest
frequency that meets a specified reliability of
communication (usually 90%). Display 6 only. An
hyphen '-' indicates that communication with the
specified reliability is improbable.

Mode Given for the MUF as the number of hops or
reflections from the E, F or S (Sporadic E)
layers. For example 4F would indicate that the
program had predicted 4 hops via the F layer.

Elev Angle of the launch of the sky wave relative to
the tangent plane of the earth at the launch site.

Output Displays 7 Output Displays 7
Service Reliabilities and Probabilities Service Reliabilities and Probabilities

These displays provide up to 24 hours, at the MUF
or FOT and 11 or up to 30 selected frequencies, of
predicted Circuit Reliabilities or Service
Probabilities depending on the setting of the F5 key.
A service probability would be that of a specified
reliability being met. Both are expressed as
percentages.

____________________

^14 This is often used in conjunction with the FOT
to show if a transmission is probable. This program
produces the Highest Reliable Frequency (HRF) which is
derived in the same way as the LUF.

OUTPUT DISPLAYS OUTPUT DISPLAYS

Output Display 8 and 9 Output Display 8 and 9
System Performance Predictions and Path Geometry System Performance Predictions and Path Geometry

Displays 8 and 9 lists the System Performance for
eleven or up to 30 selected frequencies. If more than
one hour is requested each will be calculated and
displayed in sequence. Above the table the MUF, FOT
and HPF for the time of day are listed with ESMUF,
ESFOT and ESHPF, the Sporadic E equivalents. An Escape
will terminate the hour cycle and revert to the
execution menu. Display 9 is a extended version of 8
listing more items of data.

Definitions

MUF, FOT and HPF
As for outputs methods 5 and 6 above.

ESMUF, ESFOT and ESHPF
The sporadic E equivalents of MUFs,FOTs and HPFs.

Mode The most reliable mode of transmission at the
indicated frequency, and is given as the number of
hops or reflections from the E, F, S (Sporadic E),
X (mixed E and F) or Z (mixed sporadic E and F)
layers. For example 4F would indicate that the
program predicted path of 4 hops via the F layer.

Elev Angle of the launch of the sky wave relative to
the tangent plane of the earth.

Dlay Propagation delay for the most reliable mode,
given in milliseconds.

Vhgt Virtual height, in kilometres, of reflection for
the most reliable mode. This assumes no bending
effects.

Fdys Fraction of days in the month that sky wave
propagation is expected.

OUTPUT DISPLAYS OUTPUT DISPLAYS

Emfd Monthly median Field Strength expected at receiver
location expressed in decibels relative to one
microvolt per metre.

Loss Transmission Loss expressed as the ratio of power
available at the receiver terminals relative to
that at the input to the transmitter antenna,
expressed in decibels (dB) and as a monthly median
of hourly medians.

SigR Receiver input power expressed in dBW (dB
relative to 1 Watt) as the monthly median of
hourly median power expected at the receiver
input.

NoiR The monthly median of the hourly median noise
power expected at the receiver input expressed in
dBW.

S/N Available Signal to Noise Ratio expressed in dB
(ie. SigR/NoiR).

Fs/n The fraction of days the Signal to Noise Ratio is
expected to equal or exceed that required. This
fraction only applies to those days when a sky
wave path is available.

Rel Circuit Reliability expressed as the fraction of
days that the signal quality will be acceptable
(ie. fdys x Fs/n). Only displayed when
reliability has been set by the F5 key.

Prob Probability that the specified reliability will be
achieved, expressed as a fraction. Only displayed
when probability has been set by the F5 key.

OUTPUT DISPLAYS OUTPUT DISPLAYS

Mph Probability of Multipath propagation, ie. a
secondary sky wave mode producing sufficient power
and time differences to make reception of the
primary mode unacceptable, as determined by
specified values.

Output Display 10 Output Display 10
System Performance of Individual Modes System Performance of Individual Modes

This display produces performance predictions for
one hour or a range of hours, at the MUF and up to 30
selected frequencies, for the dominant modes of
propagation.

Each hour has up to 31 displays associated with
it, plus the separately displayed header making a total
of 32 in all.

On completion of the calculations the Reflection
Area data for the current hour is displayed. By using
the up/down arrow the displays can be cycled onto the
screen. Stepping back will cause the display of the
general header. Stepping forward bring the mode
performances at the MUF or FOT onto the screen,
followed in turn by the mode performances at the other
selected frequencies after which the general header
will restart the cycle.

Reflection Area Data Reflection Area Data

The reflection area data is headed by the hour
(UTC) and provides data for the five reflection points
that are the midway and the nearest and furthest from
the transmitter for both E and F layers. Data provided
for the above points are:

1) The distance of the point from the transmitter in
kilometres.

OUTPUT DISPLAYS OUTPUT DISPLAYS

2) The geographic longitude of the point in degrees.
3) The geographic latitude of the point in degrees.
4) The geomagnetic latitude of the point in degrees.
5) The true local time at the point in hours.
6) The absorption factor of the ionosphere at the
reflection point which is mainly dependant on
zenith angle of the sun.
7) The critical frequency of the E layer in MHz, if
appropriate.
8) The height of the lower part of the F layer in
Kilometres, if appropriate.
9) The maximum height of the F layer in kilometres,
if appropriate.
10) The gyro frequency of reflection in MHz at 100 Km.
The mid-distance is given for the F layer.
11) The critical frequency of the F layer in MHz, if
appropriate.
12) The monthly median frequency in MHz supported by
sporadic E at vertical incidence, if appropriate.

Below the reflection area data are listed

13) The true time at the receiver in hours.
The average absorption factor for the path derived
from the sample areas.
The critical frequency of the E layer in MHz used
to calculate mixed mode performance.
14) The gyro frequency in MHz used to calculate
absorption.
The maximum height of F layer ionization in
kilometres.
The semi-thickness of the F layer in kilometres.
15) The F layer critical frequency in MHz used to
calculate active modes.
The maximum usable frequency MUF.
The optimum working frequency FOT.
The highest possible frequency HPF.

OUTPUT DISPLAYS OUTPUT DISPLAYS

16) The excess system loss in dB, an estimate of
propagation losses.
The sporadic E maximum usable frequency ESMUF.
The sporadic E optimum working frequency ESFOT.
The sporadic E highest possible frequency ESHPF.
17) The modified MUFs for the magnetic k-indices.

Performance tables at Specified Frequencies Performance tables at Specified Frequencies

These tables are headed both by the hour (UTC) and
the frequency followed by the values of the noise
sources at the receiver, atmospheric, galactic, man-
made and the effective total.

Seven columns provide performance predictions for
the two dominant E paths, the three dominant F paths
and the two dominant mixed mode paths. A mixed mode
path would consist of one E layer reflection plus one
or more F layer reflections. Where a sky wave is
probable the data given will consist of:

1) Number of reflections (hops).
2) Launch angle in degrees.
3) Virtual height of reflection in kilometres.
4) Delay time of transmission in milliseconds.
5) Sky wave loss in dB.
6) Ionospheric absorption loss in dB.
7) Ground reflection loss in dB.
8) Total transmission loss in dB.
9) Field strength at the receiver in dB relative to 1
microvolt.
10) Signal power at the receiver in dB relative to 1
watt.
11) Signal to noise ratio at the receiver specified in
dB relative to noise density in a 1 Hz bandwidth.
12) Probability of mode, ie fraction of days the mode
is expected to be available.

OUTPUT DISPLAYS OUTPUT DISPLAYS

13) Probability of attaining the specified signal to
noise ratio, ie fraction of days assuming 100%
mode availability.
14) Service reliability (the product of mode and
signal to noise probabilities) or, depending on
the setting of the F5 key,
Service probability (the probability of attaining
the specified service reliability).

Print or Output to File Print or Output to File

Typing 'P' during the display of an output will
cause the output to be sent to the printer queue or
file if specified. The format will depend on the
display method. In each case the header will be
displayed at the top of the first page and the whole of
the results, or that for the hour in the case of
methods 8 to 10, will be sent to the printer or file.
In the following descriptions group refers to a page as
displayed on the screen:

Methods 1 and 2
The full screen will be printed on one page.
However, MUFS and FOTs must be printed separately
if both is desired, otherwise only that displayed
will be printed.

Method 3
Although the set-up allows a minimum specified
page length of 36 lines method 3 assumes a length
of at least 60 and the whole output is printed as
if on a single page. However, only the number of
time columns that the specified page width permits
will be printed. If the page is too narrow then
the columns to be omitted will be taken from those
off the left of the screen followed by those off
the right.

OUTPUT DISPLAYS OUTPUT DISPLAYS

Methods 4 to 7
The whole 24 hours can be displayed on a single
page. However, the number of frequency columns
printed (method 7) will be determined as for the
hour columns in methods 3 above.

Methods 8 and 9
As many hour groups that the specified page length
allows will be displayed below each other on a
single page. The number of frequency columns
printed will be determined as for the columns in
method 3 above.

Method 10
As many groups that the specified page length
allows will be displayed below each other on each
page.

Direct Output to the Printer Direct Output to the Printer

If the Function Key F7 is set to 'Prnt' then the
output to the printer is automatic, ie after each
display both printing and execution of the next hour
are initiated. Columns are omitted from the right if
there are too many to fit on a page.

GRAPHIC DISPLAYS GRAPHIC DISPLAYS

7. Graphic Displays 7. Graphic Displays

Graphic Plots Graphic Plots

Each plot has a basic header, rather than the
complete version displayed with the tabulation. The
plots are designed for VGA 640 x 480 displays but
produces reasonable results on Hercules 720 x 350
displays, although the Hercules normally needs an
aspect ratio adjustment. Unfortunately results on CGA
displays are not very successful mainly due to the
large size of the characters.

Each plot is drawn from the tabulated data either
by direct plotting, as in plots 3, 4, 6 and 7, or by
linear interpretation as in the contour plots 1, 2 and
5. A minimum of cosmetics is employed.

Provision of messages on the graphics screen has
been resisted to keep clutter off hard-copies initiated
by the Print Screen Key.

Seven graphic displays are provided.
1) Contour plots for 5 values of MUF or FOT on a
radial projection from display method 1.
Contour frequencies = 5, 10, 15, 20 and 25
MHz
Radial distances = 500 to 5,000 Kms

2) Contour plots for 5 values of MUF or FOT on a
Plate Carree projection from display methods
2 or 3. Also indicates Grey Line, the solar
zenith and the position of the centre
station.
Contour frequencies = 5, 10, 15, 20 and 25
MHz

GRAPHIC DISPLAYS GRAPHIC DISPLAYS

3) 24 hour plots of MUFs and modified MUFs at 3
values of local magnetic indices from display
method 4.
Values of K = 0, 5 and 9
Frequency scale = 0 to 30 MHz

4) 24 hour plots of MUFs, FOTs and HPFs from
display method 5. May also include area of
reliable reception enclosed by the contour of
LUFs and HRFs from display method 6.
Frequency scale = 0 to 30 MHz

5) 24 hour contour plots for 5 levels of
reliability or probability from display
method 7.
Reliability levels = 10, 25, 50, 75 and 90 %
Frequency scale = 0 to 30 or 60 MHz
automatically selected

6) Plots against frequency of Field Strength at
the receiver, Received Power, Local Noise
Level and Signal to Noise Ratio from display
methods 8 and 9.
Frequency scale = 1 to 60 MHz Logarithmic
Field scale = -80 to -180 dB below 1 v/m
Signal scale = -80 to -180 dB below 1 watt
Noise scale = -80 to -180 dB below 1 watt
Signal/Noise scale = 0 to 100 dB

7) Plots against frequency of Reliability or
Probability and Multi-path Probability from
display methods 8 and 9.
Frequency scale = 1 to 60 MHz Logarithmic
Reliability/Probability scale = 0 to 100 %

Printer Output Printer Output

Hard copy of the graphics may be obtained using
the DOS facilities 'GRAPHICS' and the Print Screen Key,

GRAPHIC DISPLAYS GRAPHIC DISPLAYS

or by pressing the letter 'P'. The latter method
prints the plot on a new page with the full header and
without 90 degree rotation. However, the number of
specified printers is limited and colour devices are
not supported.

The space key can be used to change the display to
monochrome before dumping the screen via the DOS
facility to a non-colour printer. The internal dumping
does this automatically while also changing the aspect
ratio to that of the printer.

If the output is directed to a file it is sent in
the printer format so that it can be dumped at a later
date.

Key Functions Key Functions

Down arrow As for Page Down for plots 1 and 2, else
cycles plots permitted for the
associated execution method.^15
Up arrow As for Page Up for plots 1 and 2, else
as for Down arrow.
Page Down Displays next hour on plots 1 and 2.
Page Up Displays previous hour in plots 1 and 2.
Letter P Produces an hard-copy on the printer.
F6 Toggles display of MUFs or FOTs with
plots 1 and 2.
Space Toggles Colour and monochrome display.
Return,X,ESC Return to tabulated display.

____________________

^15 See Displays and Plots diagram Page 34 of the
Output Display section.

FILES FILES

8. Files 8. Files

Global and Seasonal Maps Global and Seasonal Maps

The maps are contained in thirteen separate files,
'WORLD.BIN' the basic world map and 'CALJAN.BIN'
through to 'CALDEC.BIN'.^16 These files are
supplied in binary format. The ionospheric
coefficients, supplied with the maps were derived from
measurements taken during different levels of solar
activity.

File 'WORLD.BIN' contains coefficients for the
world map of the critical frequencies of the F2 layer
(foF2) and coefficients denoting the major land masses,
ocean areas, and polar caps.

The twelve files 'CALJAN.BIN' through to
'CALDEC.BIN' contain coefficients of global averages
for each month of the year. Each file contains world
map coefficients of the M(3000)F2 factor, F layer
virtual heights, E layer and Sporadic E deciles. Also
contained are coefficients for the affect of the local
magnetic K figure and the monthly medians etc for the
calculation of atmospheric noise and path losses.

Several of the parameters in these files are
processed on entry by the date and solar levels.
Therefore the files are reloaded whenever the
calculation routines are re-run with a new date or sun
spot number.

____________________

^16 Referring to the files as global and seasonal
is purely for convenience of distinction. Each contain
both geographical and temporal parameters.

FILES FILES

Circuit and Environment Parameters Circuit and Environment Parameters

The environment files 'ENVIROMT.SAV' and
ANTENVIR.SAV are used to retain the control parameters
of the program between operations. Similarly the
control parameters of regularly used circuits can be
stored in files specified by the user, while individual
stations can have their parameters entered into the
gazetteer file. The circuit files are recognised by
the extension '.CIR'.

The deletion of entries in the gazetteer file or
the removal of redundant circuit files must be achieved
externally as no such facility is provided within the
program. All the above files are written in ASCII to
make this possible, but strict format must be
maintained when editing the gazetteer and circuit files
otherwise reading errors may occur.^17

Antenna Files Antenna Files

The antenna files are intended to be of user
construction derived either from measurements or
calculation. These are required to be in plain ASCII
text, and consist of tabulated polar diagrams of gain
preceded by a description. These files will require
the extension '.ANT'. A program for the generation of
files for three basic types of antenna is supplied with
the program.^18 Data from the antenna files will
always be loaded before each run of the a calculation
routine.

____________________

^17 See Appendix B page 62 for formats.

^18 See Appendix A page 60 for format.

FILES FILES

File Input/Output Errors File Input/Output Errors

If an error occurs when reading or writing a file
the processing will cease and an error message
displayed with the file name and line number at which
the error occurred.

If a numeric value is found in an antenna file to
be outside the permitted limits it is treated the same
as an error. However, the data from a circuit or
environment file is not checked until the reading is
complete. If an infringement of the limits is found a
warning will be displayed and the value modified to
prevent harmful effects.

ANTENNA PROGRAM

9. Antenna Program 9. Antenna Program

The antenna program has been designed to provide
calculation of the gain for three basic types of
antenna.

Base fed Vertical antenna.
Base fed Inverted 'L' antenna.
Centre fed Dipole with tilt angle option.

The measurements of height and length may be
expressed in metres or wavelengths.

Primary Menu Primary Menu

Data input is similar to that in the main program.
There is a primary menu from which either an aerial
type or a set up menu may be selected.

ΪΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΏ
³ Antenna options ³
³ ³
³ Base fed Vertical Antenna : V ³
³ End fed Inverted L Antenna : L ³
³ Centre fed Dipole Antenna : D ³
³ ³
³ General Setting Up ³
³ ³
³ Set Frequency Range : F ³
³ Set Colours : C ³
³ Common Settings : M ³
³ ³
³ Exit without saving Environment :ESC ³
³ Exit and Save Environment : X ³
³ ³
³ Enter Choice : ³
ΐΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΩ
Antenna Primary Menu Antenna Primary Menu

ANTENNA PROGRAM

Antenna Menus Antenna Menus

The antenna menus are for specifying the
parameters required to calculate its gain and radiation
resistance, and the name of file that will hold the
data. Each antenna type has its own default file name.
As in the main program the existing parameters may be
edited according to the users specified requirements.

The fields for the antenna menus are as follows.

The first field in the antenna menus provides for
an extra description to be added to the file header.

Maximum length 50 characters
Default = Blank field

Height
Vertical Conductor length
Inverted L Length of vertical section
Dipole Height of feed point

The option field may be set to metres or
wavelengths.

Range 0.01 to 999.99 metres or wavelengths
Default = 10 metres

Tilt in degrees
Vertical Not applicable
Inverted L Not applicable
Dipole Tilt of dipole in degrees from the
horizontal

Range 0 to 90 degrees
Default = 0 degrees

Length
Vertical Not applicable
Inverted L Length of horizontal section
Dipole Total length of conductor

ANTENNA PROGRAM

The option field may be set to metres or
wavelengths.

Range 0.01 to 999.99 metres or wavelengths
Default = 10 metres

Bearing, toe East of North, in degrees
Vertical Not applicable
Inverted L Direction pointed to by remote end
of horizontal section. Not
applicable if horizontal length is
set to zero
Dipole Direction pointed to by lowest end
of dipole. Not applicable if tilt
is set to 90 degrees

Range 0 to 360 degrees
Default 0 degrees (True North)

This parameter is not used in the antenna
calculations, which assumes an azimuth bearing of true
North, but is used by the main program to redirect the
antenna.

Area of Earthing Device
Vertical Area of earthing device in contact
with the soil
Inverted L As for Vertical
Dipole Not applicable

Range 0.01 to 900 square metres
Defaults 0.05 square metres

Name of File to contain the results.
Maximum length 8 characters
Defaults
Vertical = VERTICAL
Inverted L = INVERTL
Dipole = DIPOLE

The extension'.ANT' will be added tothe file name.

ANTENNA PROGRAM

Set Frequency Range Set Frequency Range

The operation of the Frequency Range menu is the
same as in the main program.

Generally the preferred choice of frequencies
would be as selected in the main program. However, if
LUFs and HRFs are to be calculated, closely spaced
frequencies could be an advantage, especially if the
antenna length is greater than a wavelength at the
higher end of the range.

The main program interpolates the frequency tables
using simple linear rules. If it is decided to
construct tables using different antennas over selected
sections of the frequency range and calculation of LUFs
and HRFs is intended, it is advisable to make the end
frequencies of adjacent antennas the same. Note that
such construction will require manual processing
outside this program.

Set Colours Set Colours

The operation of the colour menu is the same as in
the main program.

Common Parameters Menu Common Parameters Menu

The common parameters consist of local earth
conditions, the required resolution and the directory
path to where the antenna files are to be stored.

Classification of the local earth conditions with
nominated values for conductivity in milli-mhos and
permittivity respectively is as follows.

ANTENNA PROGRAM

Options g e
Perfect Reflector 0.0 0.0
Salt Water 4640.0 81.0
Polar Ice Cap 0.0 1.0
Fresh Water 1.5 80.0
Flat and Marshy 7.5 12.0
Rich Pastoral 15.0 17.0
Medium Pastoral 6.0 13.0
Clay Pastoral 4.0 13.0
Rocky and Hilly 2.0 14.0
Flat Sandy and Dry 2.0 10.0
City Industrial. Average 1.0 5.0
City Industrial. Poor 0.1 3.0
User Specified

If User Specified is selected then the following
two fields may be edited, otherwise the appropriate
values of conductivity and permittivity indicated above
will be displayed.

Conductivity of the Earth, in milli-mhos
Range 0 to 9000.0 milli-mhos
Default = 30 milli-mhos

Permittivity of the Earth (Air = 1)
Range 1 to 900.0
Default = 14

Resolution of bearing in degrees
Range 1 to 20 degrees
Default = 10 degrees

Resolution of Elevation in degrees
Range 1 to 10 degrees
Default = 10 degrees

Path to directory to hold the output file(s)
Maximum length 30 characters
Default = Current directory

ANTENNA PROGRAM

General General

Exit from the menus is by the ESC or Return key.
ESC cancels any changes while Return accepts all. Exit
from the antenna menus by the Return key also causes
the program to execute before returning to the primary
menu.

Resolution Resolution

The resolution, as well as determining the angles
between each measurement, is used to set the elements
of integration when calculating the total radiated
power and hence determines its accuracy. This can be
checked by comparing the values of radiation resistance
produced in the output file with that for a second
execution with twice the resolution ie half the
value.^19 If no change is indicated then the first
value will be adequate. Generally, excepting for
antennas that are many wavelengths long, 10 degrees is
adequate.

Antenna Gain and Losses Antenna Gain and Losses

Antenna gain is calculated against the total power
radiated after reflection thus giving loss-less gain
while maintaining the true shape of the polar diagram.

Ground reflection losses are calculated by
subtracting the square of the field of the reflected
wave from that of the incident wave.

Earth current return losses only apply to the
vertical and inverted 'L' antennas. They are
calculated from the conductivity and permittivity of
the earth assuming an hemispherical earthing conductor.
____________________

^19 The radiation resistance is listed in the
record headed 'RaR' in the antenna file.

ANTENNA PROGRAM

Environment File Environment File

As in the main program the antenna program
generates an environment file 'ANTENVIR.SAV' which if
it exists will overwrite the internal defaults, thus
retaining previous settings. Read and limit errors are
treated the same as the read errors in the main
program.

ANTENNA FILE FORMAT ANTENNA FILE FORMAT

Appendix A - Antenna File Format Appendix A - Antenna File Format

Antenna files are in ASCII. The records can be up
to 255 characters wide in accordance with DOS text
files rules. Spaces are used to separate items within
each record.

Antenna gain is always assumed to be symmetrical
about an axial reference, so only values for bearings
of 0 and 180 degrees to that reference are required.
The axial reference must be selected accordingly. This
is normally in the direction of the conductor of long
wire aerials or the beam of directional antennas.

Steerable beam antennas are assumed to be directed
at the target station so only the gain on the beam is
relevant. Thus as with omnidirectional antennas,
bearing becomes irrelevant when considering steerable
devices.

A file is divided into data blocks. Preceding the
data is a comments block. This is intended for listing
the control parameters of the antenna which is
displayed by the program when initially selected, but
otherwise ignored. A comment line must begin with a
space otherwise it will not be displayed.

The first record in a data block requires an asterisk
in column 1 to mark the beginning of the block. The
first three columns in the remaining records are
ignored by the program and can be used for annotation.
All records between the end of a data block and the
next record with an asterisk in column 1 will be
ignored by the program and can be used for additional
comments.

The first data block requires three records. The
antenna program generates a fourth which is ignored by

ANTENNA FILE FORMAT ANTENNA FILE FORMAT

the main program. The first record of the first data
block require four parameters following the asterisk.

a) The number of bearing data blocks. A value of
unity indicates an omnidirectional or steerable
antenna requiring only one block.
Range 1 to 181
b) The number of elevation data records per block.
Range 1 to 91
c) The number of frequency columns.
Range 1 to 30
d) The azimuth of the antenna's axial reference.
This is set to zero for omnidirectional and
steerable antennas.
Range 0.0 to 360.0 degrees

The second record of the first data block requires
a list of the frequencies (MHz) in ascending order for
which the data is appropriate.
Range 1.5 to 60.0 MHz

The third record of the first data block requires
a list of the losses (dB) associated with each of the
above frequencies.
Range 0.0 to 30.0 dB

The second and remaining data blocks require the
values of gain (dB) associated with the frequency
column, elevation record and bearing block. The
antenna program writes the bearing after the asterisk
in the first record of each block and the elevation at
the beginning of the remaining records. These are not
used by the prediction program which assumes that all
angles are uniformly spaced.

The second and successive records of these data
blocks will require the antenna gain (dB) for each of
the frequencies given in the first data record.
Range -30.0 to 50.0 dB

ARCHIVE FILE FORMATS ARCHIVE FILE FORMATS

Appendix B - Archive File Formats Appendix B - Archive File Formats

The Gazetteer and Circuit files are in ASCII text.
The records are less than 80 characters wide. Spaces
are used to separate items within each record.

The gazetteer file 'GAZETEER.DAT' has one Station
Record per entry and is headed by a record giving a
brief annotation of the columns.

Each Circuit file requires the extension '.CIR' to
its name to be recognised by the program. It consists
of two Station Records and one System record. It may
also contain two records of comments and three of
annotation.

The format of the records is as follows:

Gazetteer File and records 1 and 2 of Circuit File
Station parameters

Columns
1 - 24 Name of Station or Town etc
26 Longitude Hemisphere E or W
27 - 33 Longitude degrees 0 to 180
35 Latitude Hemisphere N or S
36 - 41 Latitude degrees 0 to 90
42 - 46 Transmitter Power dBW
47 - 48 Local Noise Index 1 to 6
49 - 55 User Specified Noise Level dBW/Hz
56 - 57 Antenna Pattern Index 1 to 5
59 - 66 Antenna File
67 - 71 Additional Antenna Gain dB

ARCHIVE FILE FORMATS ARCHIVE FILE FORMATS

Record 3 of Circuit File - Service parameters

Columns
1 - 12 Circuit Identifying Title
13 - 14 Service Type Index 1 to 6
15 - 16 Service Grade Index 1 to 3
17 - 21 Required S/N Ratio dB/Hz

Records 4 and 5 of Circuit File [Optional]

Columns
1 - 50 Additional Information for display
during selection by program.

Comment lines may be added to the gazetteer and
circuit files, provided an asterisk is placed in column
1. All lines beginning with an asterisk will be
ignored by the main program.

A blank field in the gazetteer file will be
ignored by the program while its associated parameter
will remain unchanged. It is thus necessary to insure
that each record is complete with name and co-
ordinates. Other fields are optional although
archiving via the program produces complete entries.

Warning it is important that any editing of these
files must be in accordance with the strict format
given above.

ENVIRONMENT FILE FORMATS ENVIRONMENT FILE FORMATS

Appendix C - Environment File Formats Appendix C - Environment File Formats

Main Program Environment File Main Program Environment File

The Environment file 'ENVIROMT.SAV' consists of
eleven records. The format is as follows.

Record 1 - Colour Style parameters

28 three column entries
Entry
Odd 8 Foreground Colour Indices 0 to 15
1 Graphics Grid Colour Index 0 to 15
5 Graphics Line Colour Indices 0 to 15
Even 8 Background Colour Indices 0 to 7
1 Graphics Background Index 0 to 15
5 Graphics Fill Indices 0 to 15
The order is as from A to ] in the
colour set-up menu.

Record 2 - Graphic Fill patterns and Line Styles

12 three column entries
Entry
1 Fill pattern control 0 to 11
0 = use fill patterns with monochrome
only, else use with colour.
2 to 6 Fill pattern indices 0 to 11
7 Line style control 0 to 4
0 = use line styles with monochrome
only, else use with colour.
8 to 12 Line style indices 0 to 4

Record 3 - Miscellaneous parameters

Columns
1 - 2 Output Printer Port 1 to 9
4 - 11 Output File

ENVIRONMENT FILE FORMATS ENVIRONMENT FILE FORMATS

12 - 15 Number of Lines per Page 36 to 200
16 - 19 Number of Columns per Page 80 to 255
20 - 23 Hours Ahead of GMT(UT) -13 to +13
24 - 29 Smoothed Sun Spot Number 0 to 300
30 - 31 Sporadic E Index 1 or 2
32 - 33 Short or Long Path Index 1 or 2
34 - 35 Reliability or Probability 1 or 2
36 - 40 Screen Aspect Ratio Modifier 0.5 to 2
41 - 42 Printer type Index 1 to 4
43 - 44 Character Suppression Index 1 to 8
45 - 46 Data Byte Format Index 1 to 3
47 - 50 Horizontal Density dpi 1 to 240
51 - 54 Vertical Density dpi 1 to 240

Records 4 to 8 - Directory paths

These records use columns 1 to 30

Record 4 Path to World data Maps
Record 5 Path to Archived Circuits and
Gazetteer
Record 6 Path to Antenna files
Record 7 Path to Video Driver files
Record 8 Path to Output File storage area

Records 9 to 11 - Printer control sequences

These records use columns 1 to 30

Record 9 Set up sequence for graphics
Record 10 Preceding graphic data string
Record 11 Restore to normal operation string

Records 12 and 13 - Station parameters

Columns
1 - 24 Name of Station or Town etc
26 Longitude Hemisphere E or W
27 - 33 Longitude degrees 0 to 180
35 Latitude Hemisphere N or S

ENVIRONMENT FILE FORMATS ENVIRONMENT FILE FORMATS

36 - 41 Latitude degrees 0 to 90
42 - 46 Transmitter Power dBW
47 - 48 Local Noise Index 1 to 6
49 - 55 User Specified Noise Level dBW/Hz
56 - 57 Antenna Pattern Index 1 to 5
59 - 66 Antenna File
67 - 71 Additional Antenna Gain dB

Record 14 - System parameters

Columns
1 - 12 Circuit Identifying Title
13 - 14 Service Type Index 1 to 6
15 - 16 Service Grade Index 1 to 3
17 - 21 Required S/N Ratio dB/Hz
20 - 24 Minimum Elevation degrees 0 to 90
25 - 27 Required Reliability % 0 to 99
28 - 32 Multipath Power Ratio dB
33 - 38 Multipath Delay Time ms
39 - 40 Frequency Table Index 0 to 5
41 - 43 Number of Frequencies 1 to 30

Records 15 and 16 - Frequencies

15 five column entries per record in sequential
order.

Antenna Environment File Antenna Environment File

The Antenna environment file consist of five
records. The format is as follows.

Record 1 - Colour Style parameters

16 three column entries
Entry
Odd Foreground Colour Indices 0 to 15
Even Background Colour Indices 0 to 7

ENVIRONMENT FILE FORMATS ENVIRONMENT FILE FORMATS

The order is as from A to P in the
colour set-up menu.

Record 2 - Path to Antenna directory

Record 3 - Antenna parameters

Columns
1 - 2 Height Wavelength/Metre 1 or 2
3 - 9 Antenna Height
10 - 11 Length Wavelength/Metre 1 or 2
12 - 18 Antenna Length
19 - 23 Dipole Tilt degrees 0 to 90
24 - 29 Azimuth Bearing degrees 0 to 360
30 - 36 Area of Earthing Device sq-m
37 - 39 Bearing Resolution degs 1 to 20
40 - 42 Elevation Resolution 1 to 10
43 - 45 Earth Classification 1 to 13
46 - 52 Earth Conductivity m-mhos
53 - 58 Earth Permittivity (air=1)
59 - 60 Frequency Table Index 1 to 5
61 - 63 Number of Frequencies 1 to 30

Records 4 and 5 - Frequencies

15 five column entries per record in sequential
order.

MISCELLANEOUS INFORMATION MISCELLANEOUS INFORMATION

Appendix D - Miscellaneous Information Appendix D - Miscellaneous Information

Operational Hints Operational Hints

While the accuracy of the predictions is effected
by that of the input data there is no necessity to lose
sleep trying to fill in every detail. For instance, it
is not always possible to know all the details of the
remote station such as the transmitter output power and
antenna etc. In such cases you may have to make
intelligent guesses and approximations.

Commercial broadcasters often publish several
different several transmitters of different power
outputs with no information on which would be used for
what and when. One might make assumptions on the
distance of the target area of the service etc, or to
assume the geometric mean power (that is average in
terms of dBW).

The omnidirectional option is recommended where
nothing is known about an antenna, or one of the other
options if an assumption of the vertical polar diagram
is thought justified.

The resolution at which parameters may be entered
is higher than normally necessary. Generally, a
coordinate error of a degree or a dB in power etc will
have little effect on the final result.

Turbo Pascal Turbo Pascal

This program has been written in Borland Turbo
Pascal and therefore uses Borland routines and
parameters. For users unfamiliar with Turbo Pascal
this section covers those items relevant to operation
of this program.

MISCELLANEOUS INFORMATION MISCELLANEOUS INFORMATION

Video Drivers
Copies of the drivers, files with the extension
'.BGI' are supplied with the program, without which the
graphics cannot operate. However, owners of Turbo
Pascal may save disc space by specifying the path to
the Pascal BGI files in the set up procedure.

Colour Indices

0 Black 8 Dark Grey
1 Blue 9 Light Blue
2 Green 10 Light Green
3 Cyan 11 Light Cyan
4 Red 12 Light Red
5 Magenta 13 Light Magenta
6 Brown 14 Yellow
7 Light Grey 15 White

Fill Pattern Indices

0 Empty
1 Solid fill
2 Horizontal lines
3 Light climbing diagonal lines
4 Heavy climbing diagonal lines
5 Heavy falling diagonal lines
6 Light falling diagonal lines
7 Light hatch
8 Heavy cross hatch
9 Interleaving line
10 Widely spaced dots
11 Closely spaced dots

Line Style Indices

0 Solid line
1 Dotted line
2 Centred dotted line
3 Dashed line
4 Widely spaced dashed line

CONVERSION TABLES CONVERSION TABLES

Appendix E - Conversion Tables Appendix E - Conversion Tables

Decibels with respect to 1 watt Decibels with respect to 1 watt

To convert dBW to power, separate the decibel
value into tens and units. Convert the units in the
table below and if positive multiply it by 10 for every
10 dBW or if negative divide by 10.

dBW units
ΪΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΏ
³dBW -9 -8 -7 -6 -5 -4 -3 -2 -1 ³
³Watts 0.13 0.16 0.20 0.25 0.32 0.40 0.50 0.63 0.79 ³
ΓΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔ΄
³dBW 0 +1 +2 +3 +4 +5 +6 +7 +8 +9 ³
³Watts 1 1.26 1.58 1.99 2.51 3.16 3.98 5.01 6.31 2.82 ³
ΐΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΩ

Examples 43 dBW = 3 + 10 + 10 + 10 + 10
which is equivalent to
1.99 x 10 x 10 x 10 x 10
= 19,900 Watts or 19.9 Kilo-Watts

-25 dBW = - (5 + 10 + 10)
which is equivalent to
0.32 / (10 x 10)
= 0.0032 Watts or 3.2 milli-Watts

CONVERSION TABLES CONVERSION TABLES

Decibels with respect to 1 microvolt Decibels with respect to 1 microvolt

To convert dBuV to microvolt, separate the
decibel value modulo twenty wise. Convert the units in
the table below and multiply by 10 for every 20 dBuV

dBuV units
ΪΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΏ
³dBuV 0 1 2 3 4 5 6 7 8 9 ³
³uV 1.0 1.12 1.26 1.41 1.58 1.78 1.99 2.24 2.51 2.82³
ΓΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔ΄
³dBuV 10 11 12 13 14 15 16 17 18 19 ³
³uV 3.16 3.55 3.98 4.47 5.01 5.62 6.31 7.08 7.94 8.91³
ΐΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΩ

Examples 26 dBuV = 6 + 20
which is the equivalent of
1.99 x 10
= 19.9 micro-Volt

38 dBuV = 18 + 20
which is the equivalent of
7.94 x 10
= 79.4 micro-Volts

LICENSE LICENSE

Appendix F - License Appendix F - License

Free use of GWPROP is granted for Amatuer
non-profit making activities.

All inquiries should be addressed to

Gordon West
11 Elmlea Drive,
Olney, Milton Keynes, Bucks,
MK46 5HU.

Tel 01234 712803
email gwd_west@compuserve.com