Training Question: Do I Have Line of Sight on This Path?

Training Question: Do I Have Line of Sight on This Path?

Given a transmitter site and a receiver site, determine if line of sight exists, and if not, estimate how much loss will be introduced based on the obstacle(s).

The two sites are:

Cheyenne Mountain Test Facility

38 44 45.00 N

104 51 39.00 W

Castle Rock Test Site

39 25 39.00 N

104 52 00.00 W

(Both of these sites are included in the Fixed Facility data base supplied with the TAP demo.)

From the Path menu, select "Path Profile":

The TAP Path Setup form is displayed:

Enter the site description, coordinates, and datum, OR use the Fixed Facility Lookup button to find each site in the data base.
If the elevation of the site is known from a map, survey, etc., click the Elevation Mode "Specified" option and enter the elevation. Otherwise, click the "Interpolated" option and the program will search for the elevation from the topographic data files.
Enter the height of the center of radiation Above Ground Level for each antenna.

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 "Path Profile" tab on the form:

Select the "Terrain Data" option for earth curvature.
Select "Base Only" for reference lines.
Select "1" for the Fresnel Zone.
Set the Fresnel Clearance Ratio to 0.5.
Set the Frequency to 450 MHz.

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 Continue button.

The path profile is displayed:

You can move the mouse along the path to see an estimate of the Bullington knife-edge loss (base on Fresnel zone penetration) of obstacles along the path. For example, the peak at 33.10 miles introduces a loss of approximately 8.52dB.
You can add text labels to the drawing.
You can add text file information to the drawing.
In TAP 4.3 and later, you can set the properties (color, line width) of different parts of the drawing.
In TAP 4.3 and later, you can export the path distance and elevation values to an ASCII file.
In TAP 4.3 and later, you can save the drawing to your own file name.