Finetuning graphs and plots
Setting up contour colors
There are three files, located in the default installation at C:\itshfbc\database\, where the contour values are defined for output parameters, to be used in VOACAP graphs & VOAAREA coverage maps:
VOACAP GPH VOACAP Point-to-Point parameter auto scaling info VOAPLT GPH VOACAP auto scaling data used by AREAPLTW.EXE
Syntax
xfact, icode, num, [ con(num) ]
Where:
xfact = multiplying factor
Usually either 1. or 100. (100 for percents)
icode = calculating code
0 = user-defined values given in CON (max of 6 allowed **)
1 = MAX down in CON(1) increments, Min allowed CON(2)
2 = MIN to MAX in 6 program-defined steps
3 = MIN up in CON(1) increments, Max allowed CON(2)
num = number of numeric arguments to follow.
con(num) = numeric arguments, up to num
If num = 2, then two arguments have to follow. They become
CON(1) and CON(2).
When num = 0, there are no numeric arguments (icode = 2).
The max value of num = 6 can only be used in the case of icode = 0.
** in reality, VOACAPW.EXE accepts 10 user-defined values. These need to be defined in the data input card.
Contour colors
The default values will be read from C:\itshfbc\database\colors.gph (for graphs) and C:\itshfbc\database\colors.con (for coverage maps). See http://www.uwasa.fi/~jpe/voacap/colors.htmlExamples
1. USER DEFINED CONTOUR VALUES (ICODE = 0)
MUFday= % of days/month sky-wave propagation expected at MUF mode
MUF days expected [%]
100. 0 6 1. 10. 50. 90. 99. 110.
Explanations:
- Multiply values in datafile by 100.
- Use 6 values given.
2. PROGRAM DEFINED MAX TO USER DEFINED MIN + INCREMENT (ICODE = 1)
DBU = Median field strength at receive location (dBu)
Field Strength Median [dBu]
1. 1 2 5. 0.
Explanations:
- Find MAX in datafile (e.g. say it was 69)
- Round up to the next multiple of CON(1) (70 in this case).
- Contours start at 70 (but you will not see this one) and go down in steps of 5 [= CON(1)] for 6 contours. The lower limit will be 0 [= CON(2)]. Thus, if max was 14, contours would be >10, 5, <0.
3. PROGRAM DEFINED MAX, MIN AND INCREMENT (ICODE = 2)
TANGLE= Radiation angle (degrees)
Radiation Angle Transmit [degrees]
1. 2 0
Explanations:
- Find MIN and MAX in datafile (e.g. 4.6, 32.3)
4. PROGRAM DEFINED MIN TO USER DEFINED MAX AND INCREMENT (ICODE = 3)
RPWRG = Required power & antenna gain to achieve reliab (dB)
Required Power & Antenna Gain [dB]
1. 3 2 10. 200.
Explanations:
- Find MIN in datafile
- Round down to the next multiple of CON(1)
- Contours start at this value and go up in steps of 10 [= CON(1)] for 6 contours. The upper limit is 200 [= CON(2)].
Setting up plot colors
There are two definition files, located in the default installation at C:\itshfbc\database\, that define the plot colors for VOACAP graphs and VOAAREA coverage maps as follows:
COLORS GPH Colors for auto contour shading for Point-to-Point plots COLORS CON Colors for auto contour shading for Area Coverage plots
Point-to-Point Plots
Colors.gph - original
8 7 1 2 3 15 Color indexes
1 4 6 56 58 59 Black/White shade codes
dark grey red gren yell whit
grey
This controls the colors used for Point-to-Point graph shading.
On the first line, place 6 colors used for auto shading.
On the 2nd line, place the shading codes to be used for black/white shading.
The right-most value corresponds to the highest value shaded.
Below is a list of the value colors that may be used.
Using an invalid color value will cause the default values to be used.
0=Black 4=Blue 8=Dark grey 12=Lite blue
1=Red 5=Magenta 9=Orange 13=Pink
2=Green 6=Cyan 10=Lite green 14=Pale blue
3=Yellow 7=Grey 11=Brown 15=White
For point-to-point graphs we could use the following color scale (originally suggested by Dan AC6LA at http://www.qsl.net/ac6la/mapcontrol.html) [from highest to lowest value]:
Red, Orange, Yellow, Light Green, Pale Blue, Grey.
For the color abbreviations, see file COLORS.WIN in the same DATABASE directory. Subsequently, you would change the first line of COLORS.GPH to:
7 14 10 3 9 1 Color indexes
Now these 6 colors are always automatically selected for graphs.
Area Coverage Plots
We will now change the Area Coverage colors accordingly:
Colors.con - original
15 7 6 14 2 3 9
whit grey cyan pale grn yell orng
blue
This controls the colors used for auto contour shading.
On the first line, place 7 colors used for auto shading.
The right-most value corresponds to the highest value shaded.
Below is a list of the value colors that may be used.
Using an invalid color value will cause the default values to be used.
0=Black 4=Blue 8=Dark grey 12=Lite blue
1=Red 5=Magenta 9=Orange 13=Pink
2=Green 6=Cyan 10=Lite green 14=Pale blue
3=Yellow 7=Grey 11=Brown 15=White
Let us use the color scale suggested by Dan AC6LA (from highest to lowest value):
Red, Orange, Yellow, Light Green, Pale Blue, Magenta, Grey.
Subsequently, you would change the two first lines of COLORS.CON to:
7 5 14 10 3 9 1
grey magn llbl lgrn yell orng red
Now these 7 colors are always automatically selected for Area Coverage plots, so no laborous manual color definitions while plotting are needed from our part.
And while using the VOAAREA program, my settings under the LAYERS button are:
- Grid = Grey
- Countries = Blue (or Black)
- Zones = Ignore
- Cities = Ignore
- MainBeam = Red
- Contours = Shading, no contours
Y-axis scaling for Time & Distance graphs
The VOACAP Time and Distance Plots (Run > Time and Run > Distance) are very informative graphs that let you compare the output parameter values for user-specified frequencies. The Time Plot lets you view the output parameters on a 24-hour scale, e.g. if you want to see which of the specified frequencies is best at the given time of day.
The Distance Plot calculates the variation of output parameter values with regards to distance at the user-specified hour.
By default, most of the output parameter values are automatically scaled. There are, however, some parameters which could benefit from a fixed Y-scale. The Y-axis scaling info is found in C:\itshfbc\database\voadist.gph.
VOADIST GPH VOACAP Point-to-Point parameter Y-scale info
Syntax
The variable names are:
xfact,icode,zmin,zmax,zlab,zinc
xfact = The multiplier factor, usually 1 or 100 [for percentages]
icode = 0 = zmin & zmax are fixed.
= 1 = zmin & zmax are calculated from data.
zmin = minimum Y value on axis
zmax = maximun Y value on axis
zlab = number label at every ZLAB increment
zinc = tick mark at every ZINC increment
Example 1
SDBW = Median signal power at receiver (dBW)
Signal Power at Receiver (dBW)
1. 0 -160. -50. 10. 2.
Explanation:
- Set the minimum value to -160 (corresponds to [median] S0 on the S-meter)
- Set the maximum value to -50 (corresponds to [median] > S9 + 40 dB)
- Set the number label at every 10th increment
- Set the Y-axis tick mark at every 2nd increment
Example 2
SNR = Median signal-to-noise ratio (dB)
Signal-to-Noise (Median) (dB)
1. 0 0. 100. 10. 2.
Explanation:
- Set the minimum value to 0. This is, in fact, too low. A minimum value of 20 would do.
- Set the maximum value to 100. For big BC stations, this can be too low a max value...
- Set the number label at every 10th increment
- Set the Y-axis tick mark at every 2nd increment
Example 3
SNRxx = Signal-to-Noise ratio (dB) at Req. Rel.
Signal-to-Noise at Req. Rel. (dB)
1. 0 0. 100. 10. 2
Explanation:
- Set the minimum value to 0. This is, in fact, too low. A minimum value of 20 would do.
- Set the maximum value to 100. Now, this can be too high a value. However, now at least, the SNR and SNRxx scales are the same.
- Set the number label at every 10th increment
- Set the Y-axis tick mark at every 2nd increment