Welcome to Doppler Systems' Web Site..
Established in 1981, Doppler Systems designs and manufactures radio direction finding equipment for amateur, commercial and government users. Fixed-site and mobile units are available for frequencies between 100 and 1000 MHz.
All of our direction finders operate on the simulated Doppler principle utilizing a patented constant impedance, smoothly varying RF summing unit for high sensitivity and high dynamic range.
Our 7000 series Multi Position Tracker (MPT) direction finder utilizes the latest technology to provide an accurate line of bearing to a radio frequency emitter. Depending on the antenna configuration it can be used as either a fixed site or a mobile direction finder. Multiple sites can be networked to provide geolocation of an RF source. In the fixed site configuration the DF antennas are mast mounted arrays of 8 biconical elements in a circular array with RF summing electronics embedded in the central hub ring. Fixed site DF's are always calibrated so that the line of bearing is relative to North.
The mobile configuration consists of the same processor coupled with a magnetically mounted summer and four vertical whip antennas. In mobile systems the DF's are calibrated so that the line of bearing is relative to the forward direction of travel of the vehicle. Factory calibration constants are built into the direction finder for many common receivers. USB host interfaces are provided to allow a GPS receiver, the DF receiver and a compass to be connected to the direction finder. A windows based software program is included that locates the tracking vehicle on a map and allows triangulation by displaying the lines of bearing taken from several locations.
Three software packages are provided with our direction finders.
- MPT User interface is used to change the DDF7000 processor settings and provides a basic interface for mobile users to determine the line-of-bearing relative to the vehicle.
- Our SignalTrack software suite is a map based solution allowing the user to display a single direction finder location or any number of networked direction finders on a map. Then using the data provided by the direction finder SignalTrack displays the bearings on the map and calculates the position of the source of the transmission. Networking can be accomplished via an Ethernet base network or a network of radio modems.
- TargetTrack is our most full featured software package providing Signal and Communications Intelligence professionals with data base archiving and retrieval of signal intercepts. It provides the same functions as SignalTrack but offers additional features for post collection data analysis.
The latest versions of all of our Windows based software programs are available for downloading from the Software page. These programs may be run in "playback" mode to see how they function. Firmware upgrades for the DFs may be downloaded from Firmware Upgrades. Hardware and software manuals are available for downloading in PDF format from Manuals.
Visit our Frequently Asked Questions page for a discussion of applications and some interesting technical issues. Also check out our Technical Application Notes for more detailed discussion of specific topics.
For more information on our products or to place an order, please see our Contact list.