Radio Coverage

I can be contacted at E-mail address:- web@g3tvu.co.uk

Found under:-

'Tools/Radio Coverage'

(A 'click' on any Red underlined name will take you to that page).

There are a number of types of direct Radio Coverage plots, plus a 'Route Radio Coverage' feature, and two ways to 'Find Best Sites' for communication. This is where locations capable of providing Radio Coverage to a number of selected Units, or to all the Waypoints generated by the Object Editor on a Route, can be plotted.

(Use Up or the Back button to return to this page).

In the following plots, the fixed Unit(s) and mobile unit - whose parameters are to be used as the receiver - have to be selected. You also have to decide on the Units of measurement and range of signal levels to be displayed, plus the maximum Range to be plotted. It should be noted that the display generated for a Fixed Unit 'Gain' antenna is as if that antenna was pointed towards a particular azimuth, and with a defined antenna Elevation tilt - it can be set as a link direction or defined in degrees, i.e. its radiation pattern and direction does apply to the plot. The antenna pattern can be shown on the plot by checking 'Draw' which creates a small drawing of the antenna pattern overlaid at its location aligned with its azimuth. Clicking on the View pattern button opens the Pattern Viewer which gives a display of the Azimuth and Elevation parameters of the antenna. The Mobile Unit however is treated as if it has an 'Omni' antenna, even if in fact a 'gain' antenna is specified in its System. The effect of this is to simulate a gain antenna at the mobile Unit which always points towards the Fixed Unit for every location.

It should also be noted that a 'mobile' unit has to be specified for the Field Strength plots, where its antenna height is taken into consideration as the unit is moved.

Note:-

With these descriptions, a 'mobile' unit is one which is being moved during the plots - a Unit called 'Mobile', with capital 'M', is a named and specified Unit as part of the Base Network Membership.

Click here to see how to change the Signal Plot legend location.

Click here for notes on Single Colour plots with customised scaling.

Click here for notes on gain antenna patterns.

Click here for a full description of the Antenna Pattern Viewer.

Click here to se how to produce a Blank white screen for Coverage plots.

Single Polar	where the performance of a single Unit coverage to a defined mobile Unit is performed in a radial sweep manner. Azimuth covered ,and radial range of the plot can be specified.
Combined Cartesian	This mode plots the coverage of one or more fixed Units to a defined mobile Unit, producing the radio coverage plots for an area in X-Y rather than radial mode. This produces a constant defined (pixel) resolution over the area. There are a number of different aspects to the operation of this feature which are shown separately below:

*Single Unit Coverage*	where only one fixed Unit is selected, and the signal levels experienced by a defined mobile unit are calculated.
Multiple Unit Coverage	where the overall Best signal level* at every point from a selected number of fixed units to a defined mobile unit is plotted.*
Best Unit	for coverage plots, where the Unit providing the best signal level is displayed from amongst the selected source Units.
Interference	An Interference plot over an area is produced between a wanted and interfering station, where the minimum signal level and interference margin can be selected and plotted as required.
Fresnel	The first Fresnel Zone clearance required for a link is selected, and a plot of areas where the criteria is achieved are plotted.

Detailed Area Coverage	Note that it is also possible to perform a defined area plot using any of the above Cartesian plot modes.

Generating a Blank white screen for Coverage plots:

With all these plots it is important to plot over a greyscale or black/white picture to avoid colour degradation. An even better way is to produce a 'Blank' picture by merging an elevation map of an area with a road map after setting the merge screen to 'Copy' and contrast set to zero, with brightness set to 2.5. This will produce a white screen referenced to the Elevation Matrix which can be saved as a new picture under the name 'Blank'.

(Don't forget to 'reset' the brightness and contrast afterwards on the Merge pane, as you may think the servers are down!)

As an alternative method of producing the blank white screen which contains the elevation data, open a Map Picture and save it as the name 'Blank'. Next open 'Picture properties' - select 'Grey scaled slope', contrast to 0% and Brightness to 100%. A click on 'Draw' will then produce a white screen which can be saved again as 'Blank'. This procedure is used to avoid overwriting the original source picture properties.

The Blank screen (which holds the elevation data) can then be used to produce the colour plots without any other detail, and saved as a new picture. These colour pictures can then be merged over any other picture you have prepared to show pertinent detail.

Note that the losses incurred by the Land foliage coverage can also be incorporated into these plots

- to see how, visit:

Note:

During plots, the computer CPU load can be reduced by pressing the 'S' key to slow down processing, or paused using the Space Bar - these actions are reported on the lower data area of the main window.

Plot Signal Strength Legend location:

The signal strength legend is visible and placed in the Top Left corner of a plot by default. If you wish to change its location - or not have it displayed - open the Single Polar Radio coverage pane.

This pane is where the details of the plot to be drawn can be seen.

When Rainbow colours are selected in the Plot area, a left click on the Colour button adjacent to the 'Fill area' produces another pane where the displayed colours may be changed and signal level ranges examined. At the lower right of this pane is the area controlling the legend position, with a check box to disable it.

Similarly for Combined Cartesian coverage, where the pane below is displayed:

A click on the Colour button in the 'Signal range to draw' area, when Rainbow colours are selected, then produces the same Rainbow colours pane as above, with the legend location being selectable.

Note:

Checking the 'Completed.wav' box on the above pane causes the computer to generate a 'Plot complete' sound when the plot generation is finished. This is a very useful feature where multi-unit high resolution plots are being performed as they can take a considerable time to complete.

It is also useful to be able to use the S and Space bar features Here to control CPU usage during the task.

Single colour Plots:

In both the Single Polar and Combined Cartesian Radio Coverage panes shown above, Rainbow Colours have been selected for the plot. By un-checking the Rainbow box, a single colour plot can be performed as shown on the Single Polar coverage page. In this case a selectable single colour is used, (in Solid or Transparent form), to show areas meeting the selected signal range criteria.

If 'Contour' is selected in the Polar Plot, this coloured line will be placed at the lower signal boundary of the plot.

With both Polar and Cartesian plots, a succession of signal range plots can be performed and 'kept in picture' with your own signal range specifications. The only thing that is required for completion is a 'custom' legend. This could be generated in an external photo program - copied - then pasted and saved in the plot produced by extracting it from the RM folder, modifying, and then returning it to the folder.

Gain Antenna Patterns:

Where a gain antenna, such as the Yagi, is selected in Network Properties for my Base unit System: