RDF Mapper

RDF Mapper is a tool for visualising bearings produced by a pseudo-doppler radio direction finder (or other bearing finding hardware). It was originally written to work with the PA8W doppler RDF.

Downloads (Version 1.0.2)

Download for Windows (32 bit)

Download for Windows (64 bit)

Download for Mac

Download Source (will run on Processing3 for Windows, Linux, Mac OS)

Required Hardware

At a minimum, the RDF Mapper requires a doppler RDF receiver which can output bearings over a serial (or USB serial) link. Additionally the mapper can take advantage of a serial (or USB serial) GPS dongle. With the GPS dongle enabled, the software will calculate heading and adjust the bearing plotting as you move around. This is particularly useful for applications where the doppler array is mounted on a vehicle.

If you're interested in building a doppler RDF I can highly recommend PA8W's (Wil's) designes which can be found here.


All configuration is done through the settings screen. The RDF and GPS serial devices can be selected, along with their baud rate. Once they're started the data coming from them will be visible in the terminals on the settings screen. The GPS device needs to output NMEA frames, and the RDF should output bearings with the format %xxx where xxx is a three digit bearing in degrees, for example %043 or %263. The RDF frame should be terminated with a trailing newline e.g. %043\n.
The number of GPS fixes averaged to give speed and heading can both be independently specified, smoothing out the noise in GPS readings. Finally, the minimum speed required to determine a heading can be set. This setting makes it possible to smooth out noise or jitter in low-speed GPS headings. If the minimum speed setting is 0, all bearings are plotted relative to north (useful for static applications).


The main screen of the RDF Mapper shows the map, the current position (from GPS) and the bearing lines (from RDF). In the top right are some map controls. At the top are zoom in and out buttons (keyboard + and -). Next, the button which resembles a target, centres the map on the current position (keyboard c), and the button below toggles whether or not the map moves with the current position (keyboard l). Finally, the bottom button removes all current bearing lines (keyboard space). The map can be moved by clicking and dragging, or using the arrow keys. The map controls can be seen in action here.

Known Limitations

RDF Mapper is written using the Processing.org framework and the Unfolding library. There are some compatibility issues with Unfolding and Processing3 which will hopefully be resolved as the Unfolding project progresses. These can result in the software failing to render maps on some systems.


Copyright 2017 Jonathan Musther

RDF Mapper is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

RDF Mapper is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

You should receive a copy of the GNU General Public License
along with RDF Mapper. If not, see <http://www.gnu.org/licenses/>.

Contact - Jonathan Musther


+64 (0) 27 749 6350