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Doppler Systems LLC

Radio Direction Finders and Direction Finding Systems

Doppler Radio Direction Finders and Direction Finding Equipment

Doppler Direction Finder Accessories

GPS Yaw Rate
Self Test


Our GPS units interface with the DDF7000 direction finders to provide geographical position and time tagging of bearing data.  In mobile applications our SignalTrack and TargetTrack software packages use the GPS measurements to locate the position of the vehicle on the map allowing the operator to view the line-of-bearing from the vehicle to the target emitter.  In fixed site applications our software uses the GPS to automatically locate the fixed site location on the map eliminating the possibility of operator error in entering the position manually.

If sites are networked the GPS provides time tagging of the data allowing real time synchronization of the data as well as facilitating post collection analysis of the log files from different sites.

 It comes preprogrammed to provide the correct data message formats and data message rates required by SignalTrack and TargetTrack.  It is available with either RS232 or USB interface and includes a magnetic mount.

GPS Used with Doppler Radio Direction Finders

Yaw Rate Sensor

The DDF7056 Yaw Rate Sensor improves the accuracy of the mobile direction finder by providing more frequent updates of the vehicle heading.  This sensor is particularly useful in applications where the vehicle is performing numerous turns.  Typically headings from a GPS are used; however, these headings occur only once per second and lag the actual heading by 1.1 seconds.  Using the yaw rate sensor in conjunction with the GPS improves the accuracy of the heading as well as providing up to date heading estimates 10 times per second. It needs to be securely mounted to the vehicle with its base parallel to the floor of the vehicle.  Includes 6 ft power (Power Pole) and data (RS232) cables.

Yaw Rate Sensor used in Mobile DF

Power Distributor

The DDF7051 mobile power distributor provides a simple way to connect all the components of a direction finder to 12 V power using only one cigar lighter outlet on the vehicle.  All of our direction finders and accessories have mating power connectors that plug directly into the power distributor for a compact and clean installation.

The DDF7052 fixed site power distributor is similar to the mobile unit except that a 13.5 V 20 A power supply is provided to power the unit off of 110 Volt or 220 volt ac power.

Mobile Power DistributorDoppler DF Fixed Site Power Supply

Self-Test Generator

Failure of a a single element of a fixed site antenna can cause significant errors in the measured bearing.  The DDF7057 Self-Test Generator insures fixed site antennas are operating correctly.  Using the Self-Test Generator and the MPT User Interface software you can automatically test each of the eight antennas in a fixed site array on all three bands.  It includes 25 ft power and data cables and antennas for VHF, UHF and THF bands. This unit should be placed between 20 ft and 200 ft from the fixed site antenna in a enclosed environment to protect from rain.

Doppler DF Self Test GeneratorDoppler DF Self Test Geneator Rear View


The compass is used in mobile applications where the vehicle is going to remain mostly stationary.  It is used to provide a vehicle heading.  It needs to be mounted away from magnetic materials (steel and iron) and must be calibrated to the magnetic environment of the vehicle.  The TargetTrack and SignalTrack software packages include compass calibration functions.

Doppler DF Compass