Training Question: Does this site provide adequate signal?

Training Question: Does this site provide adequate signal
at I-70 and I-25?

Given a transmitter site and a receiver location, does the facility provide adequate signal?

The transmitter site is:

Castle Rock Test Site

39 25 39.00 N
104 52 00.00 W

The highway intersection is at:

Mousetrap (I-70 & I-25)

39 46 30.00 N
104 59 40.00 W

Required Field Calculation

The first step is to determine what should be considered "adequate signal" for this study.

From the TAP "Utilities" menu select "Compute Required Field" to determine if this field strength level is adequate for specific receivers to be used at the target location.

Enter the manufacturer's specified receiver input voltage or power
Enter the receiver antenna gain value
Enter other gain and losses, OR use the "Gain/Loss Lookup" button to compute transmission line losses, and enter building and body losses, and other loss categories.
The program will compute the required field to achieve the needed receiver input. You can then compare this computed required level to the predicted field strength level you caclulate with the Single Point Field program below.

Predicted Field Calculation

Now that we have a value of field strength we can consider a threshold, we can compute the predicted field from the transmitter site. From the Coverage menu, select "Single Point Field":

The TAP Path Setup form is displayed:

For the Transmitter Site, use the "Fixed Facility Lookup" button to find the Castle Rock facility in the data base.
For the Receiver Site, either enter the description, coordinates, and datum for the site, OR use the "Location Lookup" button to enter the location in the data base so it can be used again later.
Enter the height of the center of radiation Above Ground Level for each antenna.
With TAP 4.3 and later you can enter the information on the TAP Path Setup form, then use the "Save to Location" button to write the values to a new record in the Location data base.

Click the Topo Data tab on the form:

Click the "Do NOT Save or Reuse Existing Elevation Data" option.
Set the data interval to 0.10 miles.
Select the FCC interpolation method for the elevation search.
Select the data resolutions to search 3-second and 30-second topographic data.
Set the effective earth curvature value to 1.333.
You can check to verify the configuration information for the topo data file locations.

Click the "Surface" tab on the form:

If any items are displayed in the Surface Features Files list, click the "Remove All" button.

Click the Propagation tab on the form.

Click the pulldown list to select the Longley-Rice propagation model. (Note that you can use any of the available propagation models in the Single Point Field mode.)
When the Longley-Rice Parameters Template is displayed, find the LR Defaults template, then click the Close button on the Template form.

Click the Continue button on the TAP Path Setup form.

The TAP Single Point Field Study form is displayed, showing the computed field strength at the target site based on the facility specified:

The computed field strength is displayed on the left side of the form (in this example, 38.19dBu. For TAP 4.3 and later, the equivalent receiver input power or voltage (assuming zero gains and losses for the receiver antenna, transmission line, etc.).