How can I obtain the actual height of the site on the map when using txsite?

Hello:

In the example CDL Channel Model Customization with Ray Tracing, a map of buildings in Hong Kong is imported. When creating a base station, the antenna height is set to 4 meters, but this base station is on top of a building. How can I obtain the actual height of this base station?

I believe a possible method could be:

1. Use readgeotable to read the building information.
2. Use isinterior to check if the site's latitude and longitude are within a building's geopolyshape.
3. If the site is within a building's geopolyshape, then the site's height would be 'buildingHeight + AntennaHeight'.

However, this method is very inefficient in the case of a large map with multiple sites. Since the site can be visualized in 3D using show, it should actually contain height information. Is there a simpler way to obtain the height of the site?

Thank you!

Answer 1

[Rangesh]

Hi Xinhua Zheng,

I understand that you are interested in determining the height of the building where the transmitter is located.

When you run the example, you can examine the cell array "rays" in the workspace. The ray object "rays{1,1}(1,1)" provides one of the paths between the transmitter (Tx) and the receiver (Rx). This contains the location of Tx and Rx which contains the height, as shown in the image below.

Please note that the height is referenced to the ellipsoid defined by the World Geodetic System of 1984 (WGS84). Depending on the standards, the height is calculated accordingly.

You can refer the following links to understand better:

• raytrace: computes the propagation paths between the Tx and RX https://in.mathworks.com/help/comm/ref/txsite.raytrace.html
• comm.Ray: object contains the properties of the RF propagation ray. https://in.mathworks.com/help/comm/ref/comm.ray.html

I hope this resolves your query.