RF Field Strength Levels with HDMapper
Displaying the appropriate field strength levels is essential to producing a meaningful coverage map. With HDMapper, you can enter levels manually, or you can use the TAP Mobile Facility Lookup function. TAP enables you to compute the required field level for different mobile equipment configurations and environmental conditions, such as body and building losses, as well as land-use characteristics that affect the local environment of each mobile unit location.
The field strength values used in the article are for example purposes only. You should compute the appropriate required field strength levels for your particular application.
After you have setup and run a TAP coverage study the HDMapper form is displayed with default settings, as shown below:
The initial default field strength break-point (used to distinguish the colors plotted on the coverage study layer of the map) is set by the mobile facility you used when you set up the coverage study. To change or add break points for different field strength levels, or to change colors of the existing settings, double click the legend entry for the field strength layer:
The Layers form is displayed with the current settings:
The default setting for coverage studies created with TAP is to plot the layer with the Value Ranges option, using the DBU_FIELD values from the coverage shape file generated by TAP. You can add more levels to plot by clicking the Add button:
After Add is selected, the new level is equal to the maximum for that field. You can either type in a new value or you can double-click the level to open the TAP Mobile Facility Lookup function.
When the Mobile Facility Lookup form is displayed, find the mobile facility record that represents the field strength level you want to add to the map and click the Continue button.
The Required Field value from the Mobile Facility Database record will be inserted into the HDMapper Layer form value:
You can repeat the process to set other levels, if desired. The order of the entries is automatically sorted, from the lowest value to the highest. The first item in the list is always shown as “Below” the lowest value you enter. You can change the Layer Name displayed in the legend and the description next to each level. You can double-click the symbols to the left of each entry to set the symbol style and color for each level. (Note that the symbol options for Tile studies will depend on the “Filled Tile” or “Symbol” selection during the Area Coverage Setup.) Here is an example of the process to change the color:
Here is an example of how to change the fill:
While this example is for a coverage layer, the same adjustments can be made to the appearance of other shape file layers. If you want to save the levels and color and fill settings for reuse at a later date, click the Save button and save the Template. When you wish to use a previously-saved template, simply click the Load button.
When you click the Continue button on the Layer, the map is displayed with the new settings.
It may be helpful to adjust the order of the layers or change other layer colors to improve the presentation: