During this guide, you'll need the following information at hand:
- The altitude (above sea level) of your antenna. To find this, you can either use a GPS, or use something like https://www.freemaptools.com/elevation-finder.htm to zoom in on the exact spot of your antenna, and then add the distance above ground level your antenna is located.
- The latitude and longitude of your antenna (to at least five decimal places). To find this, you can use the output from the elevation finder above, or you can use a GPS, or use maps.google.com to zoom in on the exact spot of your antenna, and click to get the latitude and longitude.