06 February 2012

calculating distances between cities

When I'm doing mediumwave dxing (that is, identifying and logging distant AM broadcast band stations), I like to know the distance between the transmitter site any my listening location. This isn't as exact as it could be, because most of the time I only log the city of the station license holder. This is not always the same as the location of the transmitter site. For example, KCBS AM 740 is licensed in San Francisco, CA, but their four transmitter towers are near the city of Novato; almost 30 miles north of San Francisco.

In the case of logging 10-watt Travelers' Information Stations (TIS), I like to get an exact distance. So here are some methods for determining the shortest distance between two cities or map locations:

Geobytes city distance tool - Also shows compass heading
• Great circle mapper - Focuses on the distance between two airports
• Google Maps distance calculator - Lets you zoom in to plot or move the pins
• MWList - worldwide longwave, mediumwave, and TBL database; shows logged receptions on a world map

Thanks to the folks on starchat.net irc channel #mwdx for sharing some of these resources.