Antenna Bearings – Geodesic Map
When this webpage was loaded the original IP-derived Latitude and Longitude was used to render the Antenna Bearings Map for the Grid Square location as a default. Normally, the map center accuracy should be more than adequate for HF radio DX communication purposes. However, if you wish to generate a map for any other Grid Square location, you may enter a properly formatted Maidenhead Grid below and regenerate the map.
The Antenna Bearings Map generated above is a traditional map, that has been rendered in a regular format instead of a circle as in the case of GCM projection. The map is rendered as a Mercator projection. This provides an intuitive view of geographic entities like land masses and oceans, thus making it easier to interpret. The map base is a regular Google-style map for easier recognition. The QTH location for which the geodesic path and antenna bearing angles are displayed is shown as the red colored marker for easy identification.
The antenna bearings map displays geodesic paths and short-path bearings to various DX locations from your QTH. Typically, the map would display between 13-18 DX locations across various continents depending on your home QTH. For more information on various map types and the significance of a rectangular Mercator Map in relation to HF amateur radio for DX communication, please refer to the article Geodesy for Terrestrial HF Radio.
The blue-colored arcing paths represent the actual signal paths as they propagate across long distances toward DX destinations. Unlike intuitive direction paths that one might assume, due to the spherical structure of the Earth, the shortest-distance straight-line geodesic paths as rendered on the rectangular map canvas appear as curved lines in the form of arcs. Contrary to intuition, where one might believe that a straight line drawn on a map between two locations indicates the shortest distance, these arced paths actually designate the shortest physical distance to the DX locations from your home QTH.
You will notice small red-colored rectangular boxes with numbers placed on top of each destination marker. These numbers indicate the antenna bearing beam headings to each destination from your home QTH. The antenna bearing angle to the north is 0° while the east is 90°, the south is 180°, the west is 270°, and so on. A bearing to any other destination lying between two adjacent geodesic paths lines may be roughly interpolated by looking at the map. However, the interesting thing is that most HF directional antennas have a fairly broad azimuth coverage angle. Hence, it may be unlikely that you might need to worry about swinging the beam around very often.
One must also remember the following vital aspect of directional antennas while beaming to DX destinations. Typically, the azimuth angle coverage of a directional HF radio antenna is around ±40° to ±50° for normal 2-3-5 element Yagi, 2-3 element Cubical Quad, etc. Hence, such antennas can often broadly cover an entire continent at DX distances without even having to swing the beam around for various QSOs within the region. The bottom line is that during most of the typical DX sessions, at any given point in time, it might rarely be necessary to swing the antenna around too frequently…