Direction Finder Accessories
Doppler Systems, LLC offers several direction finder accessories to optimize the function of your radio direction finder (RDF). Our RDF accessories include GPS units, Yaw Rate Sensors, Power Distributors, Self-Test Generators, and Compasses. To skip directly to an accessory of interest, click one of the targets below.
Our GPS units interface with the DDF7000 direction finders to provide geographical position and time-tagging of bearing data. Our SignalTrack and TargetTrack software packages use GPS measurements to locate the position of a vehicle on a map. As a result, this allows the operator to view the line-of-bearing from the vehicle to the target emitter. Our software also uses the GPS to automatically locate a fixed site location on the map. This, for example, can eliminate the possibility of operator error when entering the position manually.
If sites are networked, the GPS provides data time-tagging. This synchronizes data at real-time and allows one to post-analyze log files from different sites.
The GPS comes pre-programmed 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. In addition, it includes a magnetic mount.
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. With this in mind, it needs to be securely mounted to the vehicle with its base parallel to the floor. The Yaw Rate Sensor includes 6 ft power (Power Pole) and data (RS232) cables.
The DDF7051 mobile Power Distributor provides a simple way to connect all the components of a direction finder to 12 V power with 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. However, a 13.5 V 20 A power supply is provided to power the unit off of 110 Volt or 220 volt ac power.
If a single element of a fixed site antenna fails, it can cause significant errors in the measured bearing. In contrast, the DDF7057 Self-Test Generator insures that fixed site antennas are working 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 in an enclosed environment between 20 – 200 ft from the fixed site antenna.
Obviously, the Compass provides a vehicle heading. Mobile applications use the Compass when the vehicle is going to remain mostly stationary. For optimal use, we recommend mounting the Compass away from magnetic materials such as steel and iron. In addition, one should also calibrate it to the magnetic environment of the vehicle. Our TargetTrack and SignalTrack software packages include Compass calibration functions.